Section 07-01: Transmission, Automatic—AODE
1994 Mustang Workshop Manual
DIAGNOSIS AND TESTING

Pinpoint Tests

NOTE: Prior to entering Pinpoint Tests, check the system wiring harness for proper connections, bent or broken pins, corrosion, loose wires, proper routing, proper seals and their condition. Check the PCM, sensors and actuators for damage. Refer to the Powertrain Control/Emissions Diagnosis Manual.

NOTE: If electrical diagnosis has been performed and a concern still exists, refer to Diagnostic Routines.

If DTCs are present while performing the On-Board Diagnostics, refer to the On-Board Diagnostic Trouble Code Description Chart for the appropriate service procedure. Prior to entering Pinpoint Tests, refer to any TSBs and Oasis messages for AODE transmission concerns.

NOTE: Prior to entering pinpoint tests, the vehicle harness must be checked for continuity and shorts; the powertrain control module (PCM) (12A650) must be checked for any concerns. Refer to the Powertrain Control/Emissions Diagnosis Manual for proper procedures.

NOTE: If any non-transmission DTCs appear, service those codes first. They could affect the electrical operation of the transmission. Record and erase DTCs from continuous memory after service has been performed. After servicing any DTCs in the Quick Test, repeat the Quick Test.



On-Board Diagnostic Trouble Code Description Chart 
*Output circuit check, generated only by electrical symptoms.
**May also be generated by some other non-electric transmission hardware system.
Three Digit DTCa Four Digit DTCb Component Description Condition Symptom Action
111 P1111 SYSTEM Pass No malfunction detected. Malfunction not detected by PCM. PC/ED
112
113		 P0112
P0113		 IAT IAT indicates 125°C (254°F) (grounded)
IAT indicates -40°C (-40°F) (open circuit)		 Voltage drop across IAT exceeds scale set for temperature 125° C (254°F).
Voltage drop across IAT exceeds scale set for temperature -40°C (-40°F).		 Incorrect EPC pressure. Either high or low which will result in harsh or soft shifts. PC/ED
114 P0114 IAT IAT out of on-board diagnostic range IAT temperature higher or lower than expected during KOEO and KOER. Rerun on-board diagnostic at normal operating temperature. PC/ED
116 P1116 IAT ECT out of on-board diagnostic range ECT temperature higher or lower than expected during KOEO and KOER. Rerun on-board diagnostic at normal operating temperature. PC/ED
117
118		 P0117
P0118		 ECT ECT indicates 125°C (254°F)
ECT indicates -40°C (-40°F)		 Voltage drop across ECT exceeds scale set for temperature 125°C (254°F) (grounded).
Voltage drop across ECT exceeds scale set for temperature -40° C (-40°F) (open circuit).		 Torque converter clutch will always be off, resulting in reduced fuel economy. PC/ED
121 P1124 TP TP voltage high/low for on-board diagnostic. TP was not in the correct position for on-board diagnostic. Rerun at appropriate throttle position per application. PC/ED
122, 123, 124, 125, 167 P0122, P0123, P1120, P1121, P1125 TP TP concern PCM has detected an error. This error may cause a transmission concern. Harsh engagements, firm shift feel, abnormal shift schedule, torque converter clutch does not engage. Torque converter clutch cycling. PC/ED
157, 158, 159, 184, 185 P0102, P0103, P1100, P1101 MAF MAF concerns MAF system has a malfunction which may cause a transmission concern. High/low EPC pressure, incorrect shift schedule. Incorrect torque converter clutch engagement scheduling. Symptoms similar to a TP failure. PC/ED
212
211-219
221-224
232-239
241-243		 P0300-P0308
P0320, P0340
P1351-P1364		 ICM ICM concerns ICM system has a malfunction which may cause a transmission concern. Harsh engagements and shifts, late WOT shifts, no torque converter clutch engagement. PC/ED
452 P0500 VSS Insufficient input from VSS. PCM detected a loss of vehicle speed signal during operation. Torque converter clutch engages, shift engagement/disengagement (hunting) on grades. PC/ED
522 P1709 MLP MLP not in PARK. On-board diagnostic not run in PARK. Rerun on-board diagnostic in PARK. Refer to Pinpoint Test D.
536 P1703 BOO Brake not actuated during on-board diagnostic.
BOO switch circuit failed.		 Brake not cycled during KOER.
Brake ON/OFF circuit failure.		 Failed ON or not connected— torque converter clutch will not engage at less than 1/3 throttle.
Failed OFF or not connected— torque converter clutch will not disengage when brake is applied.		 PC/ED
539 P1460 A/C A/C clutch cycling pressure switch error A/C or Defrost ON condition may result from A/C clutch being ON during on-board diagnostic. DTC set during on-board diagnostic— rerun TOT—A/C OFF.
Failed ON—EPC pressure slightly low with A/C OFF.		 PC/ED
617** P1731** SS1 or internal parts 1-2 shift error Engine rpm drop not detected when 1-2 shift was commanded by PCM. Improper gear selection depending on failure or mode and manual lever position. Shift errors may also be due to other internal transmission concerns (stuck valves, damaged friction material). Refer to Solenoid On/Off Charts. Refer to Pinpoint Test A.
618** P1732** SS1, SS2 or internal parts 2-3 shift error Engine rpm drop not detected when 2-3 shift was commanded by PCM. Improper gear selection depending on failure or mode and manual lever position. Shift errors may also be due to other internal transmission concerns (stuck valves, damaged friction material). Refer to Solenoid On/Off Charts. Refer to Pinpoint Test A.
619** P1733** SS1, SS2 or internal parts 3-4 shift error Engine rpm drop not detected when 3-4 shift was commanded by PCM. Improper gear selection depending on failure or mode and manual lever position. Shift errors may also be due to other internal transmission concerns (stuck valves, damaged friction material). Refer to Solenoid On/Off Charts. Refer to Pinpoint Test A.
621* P0750* SS1 SS1 solenoid circuit failure SS1 circuit failed to provide voltage drop across solenoid. Circuit open or shorted or PCM driver failure during on-board diagnostic. Improper gear selection depending on condition mode and manual lever position. See Solenoid On/Off chart. Refer to Pinpoint Test A
622* P0755* SS2 SS2 solenoid circuit failure SS2 circuit fails to provide voltage drop across solenoid. Circuit open or shorted or PCM driver failure during on-board diagnostic. Improper gear selection depending on condition mode and manual lever position. See Solenoid On/Off chart. Refer to Pinpoint Test A
623 TBD TCIL TCIL circuit failure TCIL circuit open or shorted. Failed ON—Overdrive cancel mode on. NO flashing TCIL for EPC or sensor failure.
Failed OFF—Overdrive cancel mode never indicated. NO flashing TCIL for EPC or sensor failure.		 PC/ED
624* P1747** EPC EPC solenoid circuit failure, shorted circuit or output driver. Voltage through EPC solenoid is checked. An error will be noted if tolerance is exceeded. Short Circuit—Causes minimum EPC pressure (minimum capacity) and limits engine torque (alternate firm). Refer to Pinpoint Test E.
625* P1746** EPC Shorted PCM output driver.   Open Circuit—Causes maximum EPC pressure, harsh engagements and shifts. Refer to Pinpoint Test E.
628** P0741** Transmission Transmission slippage detected. The PCM picked up an excessive amount of slippage during normal vehicle operation. Transmission slippage/erratic or no torque converter clutch operation. Flash TCIL. Refer to Diagnosis by Symptom.
632 P1780 TCS TCS not changing states. TCS not cycled during self-test. TCS circuit open or shorted. Rerun on-board diagnostic and cycle switch. No D cancel when switch is cycled. PC/ED
634 P1709 MLP MLP out of range. Indicated voltage drop across MLP exceeds limits established for each position. Harsh engagements, firm shift feel.
No 3/4 shift.		 Refer to Pinpoint Test D.
636 P1711 TOT TOT out of on-board diagnostic range. Transmission not at operating temperature during on-board diagnostic. Warm vehicle to normal operating temperature. Refer to Pinpoint Test B.
637
638		 P0713
P0712		 TOT -40°C (-40°F) indicated TOT sensor circuit open.
157°C (315°F) indicated TOT sensor circuit grounded.		 Voltage drop across TOT sensor exceeds scale set for temperature -40°C (-40°F)
Voltage drop across TOT sensor exceeds scale set for temperature of 157°C (315°F)		 Firm shift feel. Refer to Pinpoint Test B.
639 P0720 OSS Insufficient input from Output Shaft Speed Sensor. PCM detected a loss of OSS signal during operation. Harsh shifts, abnormal shift schedule, no torque converter clutch activation. Refer to Pinpoint Test F.
652* P0743* TCC TCC solenoid circuit failure during on-board diagnostic. TCC solenoid circuit fails to provide voltage drop across solenoid. Circuit open or shorted or PCM drive failure during on-board diagnostic. Short circuit—Engine stalls in second (OD, 2 range) at low idle speeds with brake applied.
Open circuit— Torque converter clutch never engages.		 Refer to Pinpoint Test C.
654 P1705 MLP MLP not indicating PARK during KOEO. On-board diagnostic not run in PARK. Rerun on-board diagnostic in PARK Refer to Pinpoint Test A.
656** P1741** TCC Excessive torque converter clutch engagement error. Excessive variations in slip (engine speed surge) across the torque converter clutch. Engine RPM oscillation is present in 3rd gear. Refer to Pinpoint Test C.
657 P1783 TOT Transmission overtemp condition indicated. Transmission oil temperature exceeded 127°C (270°F). Increase in EPC pressure. Refer to Pinpoint Test B.
659 P1706 MLP MLP indicating PARK during operation. High vehicle speed is detected when MLP indicates PARK. EPC pressure high, all shifts firm. Refer to Pinpoint Test D
667 P0707 MLP MLP circuit below minimum voltage. MLP sensor, circuit or PCM shorted or grounded. Increase in EPC pressure. Refer to Pinpoint Test D.
668 P0708 MLP MLP circuit above maximum voltage. MLP sensor, circuit or PCM indicates open. Increase in EPC pressure. Refer to Pinpoint Test D.
675 N/A MLP MLP circuit voltage out of range. MLP sensor, circuit or PCM operating erratically. Increase in EPC pressure. Refer to Pinpoint Test D.
N/A P0751** SS1 Shift solenoid #1 functional failure. Mechanical or hydraulic failure of the shift solenoid. Improper gear selection depending on failure mode and manual lever position. Refer to Solenoid On/Off Chart. Refer to Pinpoint Test A.
N/A P0756** SS2 Shift solenoid #2 functional failure. Mechanical or hydraulic failure of the shift solenoid. Improper gear selection depending on failure mode and manual lever position. Refer to Solenoid On/Off Chart. Refer to Pinpoint Test A.
N/A P1742 TCC TCC solenoid failed ON (Calif. only). TCC solenoid has failed ON by electric, mechanical or hydraulic concern. Harsh shifts. Refer to Pinpoint Test C.
N/A P1743 TCC TCC solenoid failed ON TCC solenoid has failed ON by electric, mechanical or hydraulic concern. Harsh shifts. Refer to Pinpoint Test C.
N/A P1744 Transmission (Calif. only) Transmission slippage detected. The PCM picked up an excessive amount of slippage during normal vehicle operation. Transmission slippage/erratic or no torque converter clutch operation. Refer to Diagnosis by Symptom.
N/A P1751** SS1 Shift solenoid #1 functional failure (Calif. only). Mechanical or hydraulic failure of the shift solenoid. Improper gear selection depending on failure mode and manual lever position. Refer to Solenoid On/Off Chart. Refer to Pinpoint Test A.
N/A P1756** SS2 Shift solenoid #2 functional failure (Calif. only). Mechanical or hydraulic failure of the shift solenoid. Improper gear selection depending on failure mode and manual lever position. Refer to Solenoid On/Off Chart. Refer to Pinpoint Test A.
a 5.0L
b 3.8L
  

PINPOINT TEST A: DIAGNOSTIC TROUBLE CODES 617/P1731, 618/P1732, 619/P1733, SHIFT ERRORS; 621/P0750, 622/P0755, SOLENOID CIRCUIT FAILURES; P0751, P1751 SHIFT SOLENOID #1 MALFUNCTION; P0756, P1756 SHIFT SOLENOID #2 MALFUNCTION

Pinpoint Test A

This Pinpoint Test is intended to diagnose the shift solenoids electrical system ONLY. To prevent replacement of good components, be aware that the following areas may be at fault:

This Pinpoint Test is intended to diagnose the following components:







Solenoid PCM Signal Output Pin KOEO DTC
5.0L SS1a 51 621
5.0L SS2b 52 622
3.8L SS1a 27 P0750
3.8L SS2b 1 P0755
a SS1 = Shift Solenoid 1
b SS2 = Shift Solenoid 2
 

A1 AODE ELECTRONIC DIAGNOSTICS

Yes
REMAIN in Output State DTM. GO to A2.

No
PRESS throttle and release. If vehicle did not enter Output State DTM, REFER to Powertrain Control/Emissions Diagnosis Manual

 

A2 CHECK ELECTRICAL SIGNAL OPERATION

 CAUTION: Do not pry on connector, pull up on the connector harness.

Yes
GO to A5.

No
GO to A3.

 

A3 CHECK CONTINUITY OF SOLENOID SIGNAL AND VPWR HARNESS CIRCUITS

Yes
GO to A4.

No
SERVICE OPEN circuits. REMOVE breakout box. RECONNECT all components. REPEAT Quick Tests.

 

A4 CHECK SOLENOID HARNESS FOR SHORTS TO POWER AND GROUND

  • Ensure Breakout Box 007-00033 is installed and powertrain control module disconnected.
  • Ensure transmission harness connector is disconnected.

    NOTE: Refer to schematic and charts preceding this pinpoint test.

  • Measure resistance between PCM signal output pins and test Pin 37 and 57 for 5.0L/test Pin 71 and 97 for 3.8L at breakout box.
  • Measure resistance between PCM signal output pin and test Pins 40, 60 and 46 for 5.0L/test Pins 51, 76, 77, 103 and 91 for 3.8L at breakout box and chassis ground.
  • Is each resistance greater than 10,000 ohms?
Yes
GO to A5.

No
SERVICE short circuits. REMOVE breakout box. RECONNECT all components. REPEAT Quick Tests.

 

A5 TRANSMISSION FUNCTIONAL TEST

  • Disconnect vehicle harness at transmission.

     CAUTION: Do not attempt to pry connector. Depress tab and pull up on harness connector.

  • Install Rotunda Transmission Tester 007-00085 or equivalent to transmission connector.
  • Using tests outlined under tester instructions, perform Solenoid Function Test.

    NOTE: LED will turn GREEN when solenoid activates and turn OFF when deactivated. LED will turn RED if an ACTIVATED solenoid/harness is shorted to battery positive. LED will remain off if an ACTIVATED solenoid/harness is shorted to ground or no continuity (open circuit).

  • Does solenoid (LED GREEN) activate?
Yes
GO to A6.

No
GO to A7.

 

A6 TRANSMISSION DRIVE TEST

  • Perform the Transmission Drive Test as outlined under tester instructions Step IV, Dynamic Testing—Engine Running.
  • Does the vehicle upshift when commanded by the tester?
Yes
REFER to the Powertrain Control/Emissions Diagnosis Manual to diagnose powertrain control module or vehicle harness concerns. ERASE all codes and PERFORM the Drive Cycle Test as outlined. RE-RUN Quick Test. If DTCs are still present, REFER to Diagnosis by Symptom.

No
GO to A7.

 

A7 CHECK RESISTANCE OF SOLENOID/HARNESS

NOTE: Refer to the Transmission Tester for terminal locations.

  • Bench/Drive switch in BENCH mode.
  • Rotate gear select switch to OHMS CHECK position.
  • Connect ohmmeter negative lead to SS-1 jack and positive lead to VPWR jack on tester. This is to test SS-1.
  • Record resistance.
  • Resistance should be between 20 and 30 ohms.
  • Connect ohmmeter negative lead to SS-2 jack and positive lead to VPWR jack on tester. This is to test SS-2.
  • Record resistance.
  • Resistance should be between 20 and 30 ohms.
  • Is resistance for each solenoid between 20 and 30 ohms?




Yes
GO to A8.

No
GO to A9.

NOTE: Out of specification may be caused by internal harness or solenoid concerns.

 

A8 CHECK SOLENOID/HARNESS FOR SHORT TO GROUND

  • Check for continuity between BAT- jack (engine ground) and appropriate jack with an ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Tester Jack
    SS-1 SS-1/VPWR
    SS-2 SS-2/VPWR

  • Connection should show infinite resistance (no continuity).
  • Is there continuity?




Yes
GO to A9.

No
GO to Diagnosis by Symptom Charts.

 

A9 INTERNAL ELECTRONIC DIAGNOSTICS

  • Drain transmission fluid.
  • Remove transmission oil pan.
  • Check that the internal harness connector is fully engaged on the shift solenoid assembly.
  • Check that the internal harness connector terminals are fully seated in the connector.
  • Inspect the connector for damage.
  • Are above in good condition?
Yes
GO to A10.

No
SERVICE as required.

 

A10 CHECK INTERNAL HARNESS (CONTINUITY)

  • Disconnect internal harness from solenoid assembly (3-wire connector).

     CAUTION: Do not probe into connector terminals.

  • For SS-1, connect the positive lead from an ohmmeter to the tester jack SS-1 and the negative lead at the White wire of the 3-wire connector.
  • Record resistance. Resistance should be less than 0.5 ohm.
  • For SS-2, connect the positive lead from an ohmmeter to the tester jack SS-2 and the negative lead at the Black wire of the 3-wire connector.
  • Record resistance. Resistance should be less than 0.5 ohm.
  • For VPWR, connect positive lead to VPWR and the negative lead to the White/Black wire of the 3-wire connector.
  • Record resistance. Resistance should be less than 0.5 ohm.
  • Is resistance for each solenoid less than 0.5 ohm?
Yes
GO to A11.

No
REPLACE internal harness. GO to A12 .

 

A11 CHECK INTERNAL HARNESS (SHORTS TO GROUND)

  • Check for continuity between BAT- jack (engine ground) and the appropriate wire with an ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Wire
    SS-1 White
    SS-2 Black
    VPWR White/Black

  • Connection should show infinite resistance (no continuity).
  • Does connection show continuity?
Yes
REPLACE internal harness. GO to A12 .

No
GO to A12.

 

A12 CHECK SOLENOID RESISTANCE AT SOLENOID

  • For SS-2, check solenoid resistance by connecting an ohmmeter at the outboard No. 2 terminal and + terminal of the solenoid assembly.
  • Record resistance.
  • For SS-1, connect the ohmmeter to the center No. 1 terminal of the solenoid assembly and to the + terminal.
  • Record resistance.
  • Resistance should be between 20 and 30 ohms.



  • Is resistance for each solenoid between 20 and 30 ohms?
Yes
GO to A13.

No
REPLACE solenoid assembly.

 

A13 CHECK SOLENOID FOR SHORT TO GROUND

  • Check for continuity between BAT- jack (engine ground) and appropriate terminal with ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Terminal
    SS-1 1
    SS-2 2
    PWR +

  • Connection should show infinite resistance (no continuity).
  • Does connection show continuity?
Yes
REPLACE solenoid assembly.

No
REFER to Diagnosis by Symptom Charts.

  

PINPOINT TEST B: DIAGNOSTIC TROUBLE CODES 636/P1711: OUT OF SELF-TEST RANGE; 637/P0713: TOT SENSOR CIRCUIT OPEN; 638/P0712: TOT SENSOR CIRCUIT SHORTED; 657/P1783: TRANSMISSION OVERTEMP INDICATED

Pinpoint Test B

This Pinpoint Test is intended to diagnose the TOT sensor electrical system ONLY. To prevent replacement of good components, be aware that the following areas may be at fault:

  • Engine
    • Cooling
  • Electrical
    • Battery, Wiring Harnesses
  • Transmission
    • Internal Transmission Components, Cooling, Fluid

This Pinpoint Test is intended to diagnose the following components:

  • Transmission Wiring Harness, TOT, SIGNAL RETURN
  • Powertrain Control Module (PCM)—12A650




 

B1 AODE ELECTRONIC DIAGNOSTICS

  • Check to make sure transmission harness connector is fully seated, terminals are fully engaged in connector and in good condition before proceeding.
  • Have the items above been checked?
Yes
GO to B2.

No
PERFORM checks. ERASE codes. REPEAT Quick Test.

 

B2 CHECK ELECTRICAL SIGNAL OPERATION

  • Turn ignition switch to the OFF position.
  • Disconnect transmission connector.

     CAUTION: DO NOT PRY connector. Pull up on vehicle harness connector.

  • Using a mirror, inspect both ends of the connector for damaged or pushed out pins, corrosion, loose wires and missing or damaged seals.

    NOTE: Refer to the schematic and chart preceding this pinpoint test.

  • Connect a VOM positive test lead to TOT circuit and negative test lead to Signal Return (SIGRTN) circuit of transmission harness connector.
  • Place VOM on 20 volt scale.
  • Turn ignition switch to RUN, engine off.
  • Is voltage between 4.75 and 5.25 volts?
Yes
GO to B3.

No
REFER to Powertrain Control/Emissions Diagnosis Manual for diagnosis of NO Reference Voltage.

 

B3 CHECK CONTINUITY OF TOT AND SIG RTN CIRCUITS

  • Turn ignition switch to the OFF position.
  • Ensure that the vehicle harness is disconnected at the transmission connector.
  • Disconnect powertrain control module (PCM). Inspect for damaged or pushed out pins, corrosion or loose wires.
  • Install breakout box 007-00033. Leave powertrain control module (PCM) disconnected.

    NOTE: Refer to schematic and charts preceding this Pinpoint Test.

  • Measure resistance between PCM signal test Pin 49 for 5.0L/test Pin 37 for 3.8L at breakout box and signal test pin at transmission harness connector.
  • Measure resistance between PCM signal test Pin 46 for 5.0L/test Pin 91 for 3.8L at breakout box and signal test pin at transmission harness connector.
  • Are both resistances less than 5 ohms?
Yes
GO to B4.

No
SERVICE open circuits. REMOVE breakout box. RECONNECT all components. ERASE all codes. REPEAT Quick Tests.

 

B4 CHECK TOT CIRCUIT FOR SHORT TO VPWR AND GROUND

  • Turn ignition switch to the OFF position.
  • Ensure transmission harness connector is disconnected.
  • Disconnect powertrain control module (PCM). Inspect for damaged or pushed out pins, corrosion or loose wires.
  • Install breakout box 007-00033. Leave powertrain control module (PCM) disconnected.

    NOTE: Refer to schematic and chart preceding this Pinpoint Test.

  • Measure resistance between TOT test pin and Pins 37 and 57 for 5.0L/test Pins 71 and 97 for 3.8L at breakout box.
  • Measure resistance between TOT test pin and chassis ground.
  • Is each resistance greater than 10,000 ohms?
Yes
GO to B5.

No
SERVICE short circuit(s). REMOVE breakout box. RECONNECT all components. ERASE codes. REPEAT Quick Tests.

 

B5 CHECK RESISTANCE OF TOT SENSOR/HARNESS

NOTE: Refer to the Transmission Tester for terminal locations.

  • Vehicle must be at normal operating temperature.
  • Disconnect vehicle harness at transmission.

     CAUTION: Do not attempt to pry connector. Depress tab and pull up on harness connector.

  • Install Transmission Tester 007-00085 or equivalent to transmission connector.
  • Set Bench/Drive switch to BENCH mode.
  • Rotate gear selector switch to OHMS/DIODE CHECK position.
  • Connect ohmmeter negative lead to -TOT jack and positive lead to +TOT jack on tester.
  • Perform tests 1 and 2.

    NOTE: While perforiming Test 1 and 2, observe resistances. DTC 637 is set if resistance value exceeds 869K ohms (OPEN circuit). DTC 638 is set if resistance value falls below 597 ohms (short circuit).

  • Test 1
  • Record resistance.
  • Resistance should be approximately in the following ranges:

    TRANSMISSION FLUID TEMPERATURE
    °C °F Resistance (Ohms)
    0-20 32-58 100K-37K
    21-40 59-104 37K-16K
    41-70 105-158 16K-5K
    71-90 159-194 5K-2.7K
    91-110 195-230 2.7K-1.5K
    111-130 231-266 1.5K-0.8K

  • Test 2
  • Check for intermittent short or open.
  • If resistance was between 0.8K and 100K ohms, perform following test. If transmission is warm, allow transmission to cool. Check transmission oil temperature sensor (TOT sensor) resistance again. Compare resistance with initial resistance. Resistance should decrease if transmission was heated and should increase if transmission was allowed to cool. If correct change in resistance occurs, REPEAT Self-Test.
  • Is resistance in range?
Yes
GO to B6.

No
GO to B7.

 

B6 CHECK TOT SENSOR/HARNESS FOR SHORT TO GROUND

  • Check for continuity between BAT- jack (engine ground) and appropriate jack (-TOT and +TOT) with ohmmeter or other low current tester (less than 200 milliamps).
  • Connection should show infinite resistance (no continuity).
  • Is there continuity?




Yes
GO to B7.

No
REPEAT Quick Test if DTCs are still present. REFER to thePowertrain Control/Emissions Diagnosis Manual to diagnose harness or powertrain control module (PCM) concerns.

 

B7 INTERNAL ELECTRONIC DIAGNOSTICS

  • Drain transmission fluid.
  • Remove transmission oil pan.
  • Check that internal harness connector is fully engaged on transmission oil temperature sensor (TOT sensor).
  • Check that internal harness connector terminals are fully seated in connector.
  • Inspect the connector for damage.
  • Are above in good condition?
Yes
GO to B8.

No
SERVICE as required.

 

B8 CHECK INTERNAL HARNESS (CONTINUITY)

  • Disconnect internal harness from transmission oil temperature sensor (TOT sensor).

     CAUTION: Do not probe into connector terminals.

  • For transmission oil temperature sensor (TOT sensor), connect the positive lead from an ohmmeter to the tester +TOT jack and the negative lead at the White/Red wire of the TOT sensor connector.
  • Record resistance. Resistance should be less than 0.5 ohm.
  • Connect the positive lead from an ohmmeter to the tester -TOT jack and the negative lead at the red wire of the TOT wire connector.
  • Record resistance. Resistance should be less than 0.5 ohm.
  • Is resistance less than 0.5 ohm?
Yes
GO to B9.

No
REPLACE internal harness. GO to B10.

 

B9 CHECK INTERNAL HARNESS (SHORTS TO GROUND)

  • Check for continuity between BAT- jack (engine ground) and the appropriate wire (+TOT and -TOT) with ohmmeter or other low current tester (less than 200 milliamps).

    Sensor Wire
    TOT+ White/Red
    TOT- Red

  • Connection should show infinite resistance (no continuity).
  • Is there continuity?
Yes
REPLACE internal harness. GO to B10.

No
GO to B10.

 

B10 CHECK TOT SENSOR RESISTANCE

  • Check sensor resistance by connecting an ohmmeter at the terminals of the transmission oil temperature sensor (TOT sensor) assembly.
  • Record resistance.
  • Resistance should be in range of temperature of the vehicle.
  • Resistance should be approximately in the following ranges:

    TRANSMISSION FLUID TEMPERATURE
    °C °F Resistance (Ohms)
    0-20 32-58 100K-37K
    21-40 59-104 37K-16K
    41-70 105-158 16K-5K
    71-90 159-194 5K-2.7K
    91-110 195-230 2.7K-1.5K
    111-130 231-266 1.5K-0.8K

  • Is resistance in range?
Yes
GO to B11.

No
REPLACE transmission oil temperature sensor (TOT sensor).

 

B11 CHECK TOT SENSOR FOR SHORT TO GROUND

  • Check for continuity between engine ground and appropriate terminal with ohmmeter or other low current tester (less than 200 milliamps).

    Sensor Terminal
    TOT +/-

  • Connection should show infinite resistance (no continuity).
  • Is there continuity?
Yes
REPLACE transmission oil temperature sensor (TOT sensor).

No
RERUN Quick Test if DTC is still present. REFER to the Powertrain Control/Emissions Diagnosis Manual to diagnose harness or powertrain control module (PCM) concerns.

  

PINPOINT TEST C: DIAGNOSTIC TROUBLE CODES 628/P0741: TCC ENGAGEMENT ERROR DETECTED; 652/P0743: TCC SOLENOID CIRCUIT FAILURE; 656/P1741: TCC EXCESSIVE SLIP DETECTED; P1742: TCC SOLENOID FAILURE; P1743: TCC SOLENOID FAILURE

Pinpoint Test C

This Pinpoint Test is intended to diagnose the TCC solenoid electrical system ONLY. To prevent replacement of good components, be aware that the following areas may be at fault:

  • Engine
    • Performance, Cooling
  • Electrical
    • Battery, Input Sensors, Wiring Harnesses, BOO Switch
  • Transmission
    • Internal Transmission Components, Linkages, Cooling

This Pinpoint Test is intended to diagnose the following components:

  • Transmission Wiring Harness, TCC, VPWR
  • Powertrain Control Module (PCM)—12A650






Solenoid PCM Signal Output Pin KOEO DTC
5.0L SS1a 51 621
5.0L SS2b 52 622
5.0L TCCc 53 623, 652
3.8L SS1a 27 0750
3.8L SS2b 1 0755
3.8L TCCc 82 0743
a SS1 = Shift Solenoid 1
b SS2 = Shift Solenoid 2
c TCC = Torque Converter Clutch Solenoid
 

C1 AODE ELECTRONIC DIAGNOSTICS

  • Check to make sure the transmission harness connector is fully seated, terminals are fully engaged in connector and in good condition before proceeding.
  • Enter Output State Diagnostic Test Mode (DTM). Refer to Special Test Modes in this Section.
  • Connect Star Tester.
  • Perform KOEO test until continuous DTCs have been displayed.
  • Press throttle to WOT and release.
  • Does the vehicle enter Output State DTM?
Yes
REMAIN in Output State DTM. GO to C2.

No
PRESS throttle and release. If vehicle did not enter Output State DTM, refer to the Powertrain Control/Emissions Diagnosis Manual

 

C2 CHECK ELECTRICAL SIGNAL OPERATION

  • Disconnect transmission connector.
  • Using a mirror, inspect both ends of the connector for damaged or pushed out pins, corrosion, loose wires and missing or damaged seals.

    NOTE: Refer to the schematic and chart preceding this Pinpoint Test.

  • Connect a VOM positive lead to VPWR and the negative test lead to the solenoid circuit of the transmission vehicle harness connector.
  • Place VOM on 20 volt scale.
  • While observing VOM, press and release throttle to cycle solenoid output ON and OFF.
  • Does the suspect solenoid output voltage change at least 0.5 volt?
Yes
GO to C5.

No
GO to C3.

 

C3 CHECK CONTINUITY OF SOLENOID SIGNAL AND VPWR HARNESS CIRCUITS

  • Turn ignition switch to the OFF position.
  • Ensure transmission harness connector is disconnected.
  • Disconnect powertrain control module, inspect for damaged or pushed out pins, corrosion or loose wires.
  • Install breakout box 007-00033, leave powertrain control module disconnected.

    NOTE: Refer to the schematic and chart preceding this Pinpoint Test.

  • Measure resistance between PCM signal test Pin 53 for 5.0L/test Pin 82 for 3.8L at the breakout box and the signal pin at the transmission harness connector.
  • Measure resistance between PCM signal test Pin 37 and 57 for 5.0L/test Pin 71 and 97 for 3.8L at breakout box and the signal pin at the transmission harness connector.
  • Is each resistance less than 5 ohms?
Yes
GO to C4.

No
SERVICE open circuits. REMOVE breakout box. RECONNECT all components. REPEAT Quick Tests.

 

C4 CHECK SOLENOID HARNESS FOR SHORTS TO POWER AND GROUND

  • Ensure breakout box 007-00033 is installed and powertrain control module disconnected.
  • Ensure transmission harness connector is disconnected.

    NOTE: Refer to schematic and chart preceding this Pinpoint Test.

  • Measure resistance between PCM signal output pins and test Pins 37 and 57 for 5.0L/test Pins 71 and 97 for 3.8L at breakout box.
  • Measure resistance between PCM signal output pin and test Pins 40 and 60 and 46 for 5.0L/test Pins 51, 76, 77, 103 and 91 for 3.8L at breakout box and chassis ground.
  • Is each resistance greater than 10,000 ohms?
Yes
GO to C4.

No
SERVICE short circuit(s). REMOVE breakout box. RECONNECT all components. REPEAT Quick Tests.

 

C5 TRANSMISSION FUNCTIONAL TEST

  • Disconnect vehicle harness at transmission.

     CAUTION: Do not pry connector. Press the tab and pull on vehicle harness connector.

  • Install Rotunda Transmission Tester (007-00085) or equivalent to transmission connector.
  • Using tests outlined under Tester Instructions, perform torque converter clutch solenoid function test.

    NOTE: LED will turn GREEN when torque converter clutch solenoid activates and turn OFF when deactivated. LED will turn RED if an ACTIVATED solenoid/harness is shorted to battery positive. LED will remain off if an ACTIVATED solenoid/harness is shorted to ground or no continuity (open circuit).

  • Does MCCC (LED GREEN) activate when tester switch is pressed?
Yes
GO to C6.

No
GO to C7.

 

C6 TRANSMISSION DRIVE TEST

  • Perform Transmission Drive Test as outlined under testing instructions.
  • While in second gear press the MCCC switch.
  • Does the torque converter clutch solenoid activate (LED GREEN)?
  • Does the engine rpm drop?
Yes
REFER to Powertrain Control/Emissions Diagnosis Manual to diagnose powertrain control module and vehicle harness concerns.

No
GO to C7.

 

C7 CHECK RESISTANCE OF SOLENOID/HARNESS

NOTE: Refer to Transmission Tester for terminal locations.

  • Set Bench/Drive switch to BENCH mode.
  • Rotate gear select switch to OHMS CHECK position.
  • Connect ohmmeter negative lead to MCCC (jack) and positive lead to VPWR on tester.This is to test torque converter clutch solenoid.
  • Record resistance.
  • Resistance should be between 1 and 3 ohms.
  • Is resistance between 1 and 3 ohms?
Yes
GO to C8.

No
GO to C9.

NOTE: Internal harness or torque converter clutch solenoid may be damaged.

 

C8 CHECK SOLENOID/HARNESS FOR SHORT TO GROUND

  • Check for continuity between BAT- jack (engine ground) and appropriate jack with an ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Tester Jack
    TCC MCCC

  • Connection should infinite resistance (no continuity).
  • Is there continuity?




Yes
GO to C9.

No
REFER to Diagnosis by Symptom Charts.

 

C9 INTERNAL ELECTRONIC DIAGNOSTICS

  • Drain transmission fluid.
  • Remove transmission oil pan.
  • Check that internal harness connector is fully engaged on the torque converter clutch solenoid assembly.
  • Check that internal harness connector terminals are fully seated in the connector.
  • Inspect the connector for damage.
  • Are above in good condition and engaged properly?
Yes
GO to C10.

No
SERVICE as required.

 

C10 CHECK INTERNAL HARNESS (CONTINUITY)

  • Disconnect internal harness from torque converter clutch solenoid assembly (TCC wire connector).

     CAUTION: Do not probe into connector terminals.

  • Connect positive lead from an ohmmeter to tester MCCC jack and the negative lead at the Green wire of the TCC connector.
  • Record resistance. Resistance should be less than 0.5 ohm.
  • Connect the positive lead from an ohmmeter to the tester VPWR jack and the negative lead to the White/Green wire of the TCC connector.
  • Record resistance. Resistance should be less than 0.5 ohm.
  • Is resistance less than 0.5 ohm?
Yes
GO to C11.

No
REPLACE internal harness. GO to C12 .

 

C11 CHECK INTERNAL HARNESS (SHORTS TO GROUND)

  • Check for continuity between BAT- jack (engine ground) and the appropriate wire with an ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Wire
    TCC Green
      White/Green

  • Connection should show infinite resistance (no continuity).
  • Is there continuity?
Yes
REPLACE internal harness. GO to C12 .

No
GO to C12.

 

C12 CHECK SOLENOID RESISTANCE

  • For TCC, check solenoid resistance by connecting an ohmmeter to the terminals of the torque converter clutch solenoid assembly.
  • Record resistance.
  • Resistance should be between 1 and 3 ohms.
  • Is resistance between 1 and 3 ohms?
Yes
GO to C13.

No
REPLACE torque converter clutch solenoid assembly.

 

C13 CHECK SOLENOID FOR SHORT TO GROUND

  • Check for continuity between BAT- jack (engine ground) and appropriate solenoid terminals with ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Terminal
    TCC +/-

  • Connection should show infinite resistance (no continuity).
  • Is there continuity?
Yes
REPLACE torque converter clutch solenoid assembly.

No
REFER to Diagnosis by Symptom Charts.

  

PINPOINT TEST D: DIAGNOSTIC TROUBLE CODES 634/P0705: MLP SENSOR VOLTAGE HIGHER/LOWER THAN EXPECTED; 522/P1709: MLP SENSOR NOT INDICATING PARK DURING KOEO; 654/P1704: MLP SENSOR INDICATING PARK DURING KOEO; 659/P1706: MLP SENSOR INDICATING PARK DURING OPERATION; 667/P1707: MLP SENSOR OUT OF RANGE (SHORTED); 668/P1708: MLP SENSOR OUT OF RANGE (OPEN); 675: MLP SENSOR IN RANGE FAILURE

Pinpoint Test D

This Pinpoint Test is intended to diagnose the Manual Lever Position Sensor electronic system ONLY. To prevent replacement of good components, be aware that the following areas may be at fault:

  • Engine
    • Starter, Starter Relay
  • Electrical
    • Battery, Ignition Switch, Wiring Harness
  • Transmission
    • Internal Transmission Components, Linkages

This Pinpoint Test is intended to diagnose the following components:

  • Transmission Wiring Harness, MLP, Signal Return
  • Powertrain Control Module (PCM)—12A650
  • Starter Circuits, Backup Circuit










COMPONENT TESTING PROCEDURE
To Test Connect Self-Powered Test Lamp or Ohmmeter to Terminals Move Switch to These Positions A Good Switch Will Indicate
Transmission Circuits 359 (GY/R) Park 3770-4507 ohms
    Reverse 1304-1593 ohms
  and Neutral 660-807 ohms
    Overdrive 361-442 ohms
  199 (LB/Y) Second (2) 190-232 ohms
    First (1) 78-95 ohms
Backup Lamp Circuit 294 (W/LB) Park Greater than 100K ohms
    Reverse Greater than 100K ohms
  and Neutral Greater than 100K ohms
    Overdrive Greater than 100K ohms
  140 (BK/PK) Second (2) Less than 5 ohms
    First (1) Greater than 100K ohms
Starter Relay Circuit 33 (W/PK) Park Less than 5 ohms
    Reverse Greater than 100K ohms
  and Neutral Less than 5 ohms
    Overdrive Greater than 100K ohms
  32 (R/LB) Second (2) Greater than 100K ohms
    First (1) Greater than 100K ohms

 

D1 AODE MLP SENSOR ELECTRONIC DIAGNOSTICS

  • Check to make sure MLP sensor harness connector is fully seated, terminals are fully engaged in connector and in good condition before proceeding.
  • Verify shift linkage adjustment in the OVERDRIVE position.
  • Turn ignition switch to the OFF position.
  • Apply parking brake.
  • Place transmission in NEUTRAL.
  • Verify that Manual Lever Position Sensor Alignment Tool T93P-70010-A or equivalent fits in the appropriate slots.
  • Is the sensor properly adjusted?
Yes
REMOVE tool. GO to D2.

No
ADJUST sensor as outlined under In-Vehicle Service. After adjustments, PLACE transmission range selector lever in PARK. CLEAR DTC and REPEAT Quick-Test.

 

D2 CHECK ELECTRICAL SIGNAL OPERATION

  • Turn ignition switch to the OFF position.
  • Disconnect transmission connector.

     CAUTION: DO NOT pry on connector. Pull up on vehicle harness connector.

  • Using a mirror, inspect both ends of the connector for damaged or pushed out pins, corrosion, loose wires and missing or damaged seals.

    NOTE: Refer to the schematic and chart preceding this Pinpoint Test.

  • Connect a VOM positive test lead to TFT circuit and negative test lead to Signal Return (SIG RTN) circuit of transmission harness connector.
  • Place VOM on 20 volt scale.
  • Turn ignition switch to the ON position, engine OFF.
  • Is voltage between 4.75 and 5.25 volts?
Yes
GO to D3.

No
REFER to the Powertrain Control/Emissions Diagnosis Manual for diagnosis of NO Reference Voltage.

 

D3 CHECK CONTINUITY OF MLP SENSOR HARNESS CIRCUITS

  • Turn ignition switch to the OFF position.

     CAUTION: Do not pry connector. Press button and pull up on vehicle harness.

  • Disconnect MLP sensor.
  • Inspect for damage or pushed out pins, corrosion or loose wires.
  • Install Breakout Box 007-00033. Leave PCM disconnected.
  • Disconnect powertrain control module (PCM). Inspect for damaged or pushed out pins, corrosion or loose wires.

    NOTE: Refer to the schematics and charts preceding this Pinpoint Test.

  • Measure resistance between PCM test Pin 46 for 5.0L/test Pin 91 for 3.8L at breakout box and SIG RTN circuit at MLP sensor vehicle harness connector.
  • Measure resistance between PCM test Pin 30 for 5.0L/test Pin 64 for 3.8L at breakout box and MLP signal circuit at MLP sensor vehicle harness connector.
  • Is each resistance less than 5 ohms?
Yes
GO to D4.

No
SERVICE open circuit(s). REMOVE breakout box. RECONNECT all components. ERASE codes. REPEAT the Quick Test.

 

D4 CHECK MLP SENSOR CIRCUIT FOR SHORTS TO POWER AND GROUND

  • Ensure Breakout Box 007-00033 is installed and PCM disconnected.
  • Ensure MLP sensor harness connector is disconnected.

    NOTE: Refer to schematics and charts preceding this Pinpoint Test.

  • Measure resistance between PCM test Pins 30, 37, 57, 40, 60 and 46 for 5.0L/test Pins 64, 71, 97, 51, 76, 77, 103 and 91 for 3.8L.
  • Measure resistance between PCM test Pin 30 at breakout box and chassis ground.
  • Is each resistance greater than 10,000 ohms?
Yes
GO to D5.

No
SERVICE short circuit. REMOVE breakout box. RECONNECT all components. ERASE codes. REPEAT the Quick-Test.

 

D5 CHECK OPERATION OF MLP SENSOR

  • Disconnect MLP sensor harness connector at the transmission.
  • Connect Rotunda Transmission Tester (007-0085C) with MLP Sensor Cable (007-00086) or equivalent to MLP Sensor.
  • Using procedures provided with the tester, verify ALL MLP sensor functions in all positions as listed.

    COMPONENT TESTING PROCEDURE CHART
    To Test Connect Ohmmeter to Terminals Move Transmission Range Selector Lever to These Positions A Good MLP Sensor Will Indicate
    MLP Sensor Circuits 359 (GY/R) and 199 (LB/Y) P 3770-4607 Ohms
    4.41 Volts
        R 1304-1593 Ohms
    3.60 Volts
        N 660-807 Ohms
    2.93 Volts
        D 361-442 Ohms
    2.09 Volts
        2 190-232 Ohms
    1.37 Volts
        1 78-95 Ohms
    0.68 Volts
    Backup Lamp Circuits 298 (P/O) and 140 (BK/PK) P Less than 5.0 Ohms
        R Greater than 100K ohms
        N Greater than 100K Ohms
        D Greater than 100K Ohms
        2 Greater than 100K Ohms
        1 Greater than 100K Ohms
    Starter Circuits 33 (W/PK) and 32 (R/LB) P Less than 5.0 Ohms
        R Greater than 100K Ohms
        N Less than 5.0 Ohms
        D Greater than 100K Ohms
        2 Greater than 100K Ohms
        1 Greater than 100K Ohms

  • Is the MLP Sensor OK?
Yes
Concern is not in MLP sensor. If directed here from Diagnosis by Symptom, RETURN to Routine. If diagnosing a DTC, REFER to the Powertrain Control/Emissions Diagnosis Manual to diagnose intermittent concerns.

No
REPLACE MLP sensor and ADJUST. REFER to Installation and Adjustment procedures as outlined under Transmission, Assembly. ERASE DTCs and RERUN Quick Test.

  

PINPOINT TEST E: DIAGNOSTIC TROUBLE CODES 624/P1747: EPC CIRCUIT FAILURE; 625/P1746: EPC DRIVE CIRCUIT OPEN IN PCM

Pinpoint Test E

This Pinpoint Test is intended to diagnose the EPC solenoid electrical system ONLY. To prevent replacement of good components, be aware that the following areas may be at fault:

  • Engine
    • Performance
  • Electrical
    • Battery, Input Sensors, Wiring Harnesses
  • Transmission
    • Internal Transmission Components, Cooling

This Pinpoint Test is intended to diagnose the following components:

  • Transmission Wiring Harness, EPC, EPCPWR
  • Powertrain Control Module (PCM)—12A650






Solenoid PCM Signal Output Pin KOEO DTC
5.0L SS1a 51 621
5.0L SS2b 52 622
5.0L TCCc 53 623, 522
5.0L EPCd 35 624, 625
3.8L SS1a 27 P0750
3.8L SS2b 1 P0755
3.8L TCCc 82 P0743
3.8L EPCd 81 P1746, P1747
a SS1 = Shift Solenoid #1
b SS2 = Shift Solenoid #2
c TCC = Torque Converter Clutch Solenoid
d EPC = Electronic Pressure Control Solenoid
 

E1 AODE CHECK VPWR TO SOLENOID

  • Check to make sure transmission harness connector is fully seated, terminals are fully engaged and in good condition before proceeding.
  • Turn ignition switch to the OFF position.

     CAUTION: Do not pry on connector. Press button and pull up on vehicle harness.

  • Disconnect transmission connector.

    NOTE: Refer to the schematic and charts preceding this Pinpoint Test.

  • Turn ignition switch to RUN, engine OFF.
  • Measure the voltage between EPC PWR circuit at transmission harness connector and chassis/battery ground.
  • Is voltage greater than 10.5 volts?
Yes
GO to E2.

No
SERVICE open in the harness. RECONNECT all components. ERASE codes. REPEAT Quick Test.

 

E2 CHECK CONTINUITY OF SOLENOID SIGNAL AND VPWR HARNESS CIRCUITS

  • Turn ignition switch to the OFF position.
  • Disconnect Powertrain Control Module (PCM). Inspect for damaged or pushed out pins, corrosion or loose wires.
  • Install Breakout Box 007-00033. Leave PCM disconnected.

    NOTE: Refer to the schematic and charts preceding this Pinpoint Test.

  • Measure resistance between PCM test Pins 37 and 57 for 5.0L/test Pins 71 and 97 for 3.8L at breakout box and EPC PWR circuit at transmission harness connector.
  • Measure resistance between PCM test Pin 38 for 5.0L/test Pin 81 for 3.8L at breakout box and EPC signal pin at transmission harness connector.
  • Is each resistance less than 5 ohms?
Yes
GO to E3.

No
SERVICE open circuit(s). REMOVE breakout box. RECONNECT all components. ERASE codes and REPEAT OBD Tests.

 

E3 CHECK HARNESS FOR SHORT TO POWER AND GROUND

  • Turn ignition switch to the OFF position.
  • Ensure Breakout Box 007-00033 is installed, PCM is disconnected.
  • Ensure transmission connector is disconnected.

    NOTE: Refer to the schematic and charts preceding this Pinpoint Test.

  • Measure resistance between EPC circuit PCM test Pin 38 and Pins 37 and 57 for 5.0L/test Pin 81 and Pins 71 and 97 for 3.8L at breakout box.
  • Measure resistance between EPC circuit PCM test Pin 38 and Pins 40, 60 and 46 for 5.0L/test Pins 81, 51, 76, 77, 103 and 91 for 3.8L at breakout box.
  • Is each resistance greater than 10,000 ohms?
Yes
GO to E4.

No
SERVICE short circuit(s). RECONNECT all components. ERASE codes and REPEAT OBD Tests.

 

E4 TRANSMISSION FUNCTIONAL TEST

  • Disconnect vehicle harness at transmission.

     CAUTION: Do not attempt to pry the connector. Depress tab and pull up on harness connector.

  • Install line pressure gauge at line tap on case.
  • Install Rotunda Transmission Tester 007-00085 or equivalent to transmission connector.
  • Set Bench/Drive switch to DRIVE mode.
  • Rotate gear select switch to first gear position.
  • Using tests outlined under tester instructions, perform the EPC function test.

    NOTE: LED will turn GREEN when EPC solenoid activates and turn OFF when deactivated. LED will turn RED if an ACTIVATED solenoid/harness is shorted to battery positive. LED will remain off if an ACTIVATED solenoid/harness is shorted to ground or no continuity (open circuit).

    Does the EPC (GREEN LED) activate when EPC switch is pressed?Observe line pressure on the gauge while pressing EPC switch (vehicle must be running).Does the line pressure drop?
Yes
REFER to Powertrain Control/Emissions Diagnosis Manual to diagnose powertrain control module (PCM) or vehicle harness concerns.

No
GO to E5.

 

E5 CHECK RESISTANCE OF SOLENOID/HARNESS

NOTE: Refer to the Transmission Tester for terminal locations.

  • Set Bench/Drive switch to BENCH mode.
  • Rotate Gear Select switch to OHMS CHECK position.
  • Connect ohmmeter negative lead to VPWR jack and positive lead to EPC jack on tester. This is to test EPC solenoid.
  • Record resistance.
  • Resistance should be between 2.48 and 5.66 ohms.
  • Is resistance between 2.48 and 5.66 ohms?
Yes
GO to E6.

No
GO to E7.

NOTE: Out of specification may be caused by internal harness or EPC solenoid concerns.

 

E6 CHECK SOLENOID/HARNESS FOR SHORT TO GROUND

  • Check for continuity between BAT- jack (engine ground) and appropriate jack with an ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Tester Jack
    EPC EPC
      VPWR

  • Connection should show infinite resistance (no continuity).
  • Is there continuity?




Yes
GO to E7.

No
REFER to Diagnosis by Symptom Charts.

 

E7 INTERNAL ELECTRONIC DIAGNOSTICS

  • Drain transmission fluid.
  • Remove transmission oil pan.
  • Check that internal harness connector is fully engaged on EPC solenoid assembly.
  • Check that internal harness connector terminals are fully seated in connector.
  • Inspect connector for damage.
  • Are above properly engaged and in good condition?
Yes
GO to E8.

No
SERVICE as required.

 

E8 CHECK INTERNAL HARNESS (CONTINUITY)

  • Disconnect internal harness from EPC solenoid assembly.
  • Connect the positive lead from an ohmmeter to the tester EPC jack and the negative lead at the Blue wire at the EPC wire connector.
  • Record resistance. Resistance should be less than 0.5 ohm.
  • Connect the positive lead from an ohmmeter to the tester VPWR jack and the negative lead at the White/Blue wire at the EPC wire connector.
  • Record resistance. Resistance should be less than 0.5 ohm.
  • Is resistance less than 0.5 ohm?
Yes
GO to E9.

No
REPLACE internal harness. GO to E10 .

 

E9 CHECK INTERNAL HARNESS (SHORTS TO GROUND)

  • Check for continuity between BAT- jack (engine ground) and the appropriate wire with an ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Wire
    EPC Blue (Signal)
      White/Blue (EPCPWR)

  • Connection should show infinite resistance (no continuity).
  • Is there continuity?
Yes
REPLACE internal harness. GO to E10 .

No
GO to E10.

 

E10 CHECK SOLENOID RESISTANCE

  • Check solenoid resistance by connecting an ohmmeter at the EPC solenoid terminals of the solenoid.
  • Record resistance.
  • Resistance should be between 2.48 and 5.66 ohms.
  • Is resistance between 2.48 and 5.66 ohms?
Yes
GO to E11.

No
REPLACE EPC solenoid.

 

E11 CHECK SOLENOID FOR SHORT TO GROUND

  • Check for continuity between BAT- jack (engine ground) and appropriate terminal with ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Terminal
    EPC +/-

  • Connection should show infinite resistance (no continuity).
  • Is there continuity?
Yes
REPLACE EPC solenoid.

No
REFER to Diagnosis by Symptom Charts.

  

PINPOINT TEST F: DIAGNOSTIC TROUBLE CODE 639/P0720: INSUFFICIENT INPUT FOR OUTPUT SHAFT SPEED SENSOR

Pinpoint Test F

This Pinpoint Test is intended to diagnose the OSS sensor electrical system ONLY. To prevent replacement of good components, be aware that the following areas may be at fault:

  • Electrical
    • Battery, Input Sensors, Wiring Harnesses
  • Transmission
    • Internal Transmission Components

This Pinpoint Test is intended to diagnose the following components:

  • Transmission Wiring Harness, OSS, SIGNAL RETURN
  • Powertrain Control Module (PCM)—12A650




 

F1 AODE ELECTRONIC DIAGNOSTICS

  • Check that the output shaft speed sensor connector is fully seated, terminals are fully engaged in the connector and in good condition.
  • Have the items above been checked?
Yes
GO to F2.

No
PERFORM the checks. ERASE codes. RERUN OBD Tests.

 

F2 CHECK CONTINUITY OF OSS HARNESS CIRCUITS

  • Turn ignition switch to the OFF position.
  • Disconnect OSS.

     CAUTION: Do not pry on connector. Pull up on vehicle harness.

  • Disconnect powertrain control module (PCM). Inspect for damaged or pushed out pins, corrosion or loose wires.
  • Install breakout box, leave powertrain control module (PCM) disconnected.

    NOTE: Refer to schematics and charts preceding this Pinpoint Test.

  • Measure resistance between PCM test Pin 5 for 5.0L/test Pin 84 for 3.8L at breakout box and OSS(+) signal circuit at the OSS harness connector.
  • Measure resistance between PCM test Pin 46 for 5.0L/test Pin 24 for 3.8L at breakout box and OSS(-) signal circuit at the OSS harness connector.
  • Is each resistance less than 5 ohms?
Yes
GO to F3.

No
SERVICE open circuit(s). REMOVE breakout box. RECONNECT all components. ERASE codes. RERUN OBD Tests.

 

F3 CHECK OSS CIRCUITS FOR SHORT TO POWER AND GROUND

  • Turn ignition switch to the OFF positon.
  • OSS disconnected.
  • Breakout box installed, PCM disconnected.
  • Measure resistance between PCM test Pins 5, 46 and test Pins 37 and 57 for 5.0L/test Pins 84, 24 and test Pins 71 and 97 for 3.8L at breakout box.
  • Measure resistance between PCM test Pins 5, 46, 37 and 57 and PCM test Pins 40 and 60 for 5.0L/test Pins 84, 24, 71, 97, 51, 76, 77 and 103 for 3.8L at breakout box.
  • Is each resistance greater than 10,000 ohms?
Yes
GO to F4.

No
SERVICE short circuit(s). REMOVE breakout box. RECONNECT all components. ERASE codes and RERUN OBD Tests.

 

F4 TRANSMISSION FUNCTIONAL TEST

  • Disconnect vehicle harness at OSS sensor.

     CAUTION: Do not attempt to pry on the connector. Pull on harness connector.

  • Install Rotunda Transmission Tester 007-00085 or equivalent onto transmission speed sensor.
  • Connect voltmeter positive lead to +OSS and the negative lead to -OSS. Set voltmeter to AC.
  • Perform OSS Function Test. Monitor voltmeter.
  • Does the voltage increase with an increase in vehicle speed?
Yes
REFER to the Powertrain Control/Emissions Diagnosis Manual to diagnose vehicle harness or powertrain control module (PCM) concerns.

No
GO to F5 .

 

F5 CHECK RESISTANCE OF OUTPUT SHAFT SPEED SENSOR

NOTE: Refer to the Transmission Tester for terminal locations.

  • Connect ohmmeter negative lead to +OSS jack and positive lead to -OSS jack on tester. This is to test OSS sensor.
  • Record resistance. Resistance should be between 450 and 750 ohms.
  • Is resistance between 450 and 750 ohms?
Yes
GO to F6.

No
REPLACE OSS sensor. RERUN OSS Function Test.

 

F6 CHECK SENSOR FOR SHORT TO GROUND

  • Check for continuity between BAT- jack (engine ground) and appropriate jack with an ohmmeter or other low current tester (less than 200 milliamps).

    Solenoid Tester Jack
    OSS +OSS
      -OSS

  • Connection should show infinite resistance (no continuity).
  • Is there continuity?




Yes
REPLACE OSS sensor. RERUN OSS Function Test.

No
GO to F7 .

 

F7 CHECK OSS MAGNETISM

  • Remove OSS sensor from transmission.
  • Place OSS sensor against a metal surface to which a magnet would stick. The OSS sensor should be magnetized and stick to the metal surface.
  • Does OSS stick?

GO to F8 .


REPLACE OSS sensor. RERUN OSS Function Test.

 

F8 CHECK OUTPUT SHAFT RING GEAR

  • With OSS sensor removed and transmission in NEUTRAL, rotate driveshaft and observe through the OSS sensor hole in case that all six holes or indentations in the ring gear are present and free of foreign material.
  • Are holes present and free of foreign material?

REPLACE OSS sensor. RERUN OSS Function Test.


REFER to Disassembly and Assembly to service output shaft ring gear. SERVICE or REPLACE as required.