Section 01-14B: Door Lock Control System, Electronic
1994 Mustang Workshop Manual
DIAGNOSIS AND TESTING

Pinpoint Tests

  

PINPOINT TEST A: DOORS DO NOT LOCK OR UNLOCK USING REMOTE TRANSMITTER

 

A1 OPERATE LOCKS FROM DOOR LOCK SWITCHES

Yes
GO to A2.

No
REFER to Section 01-14A.

 

A2 CHECK BATTERY SAVER FEATURE

Yes
GO to A3.

No
PERFORM Pinpoint Test B or Pinpoint Test F.

 

A3 CHECK PROGRAM CONNECTOR

  • Turn ignition switch to RUN.
  • Momentarily insert a shorting plug into program connector.

    NOTE: This shorting plug connects Program A input to Program B on the electronic door lock control processor .

  • Do doors lock and unlock?
Yes
GO to A4.

No
GO to A15 .

 

A4 LOCK DOORS USING TRANSMITTER

  • Remove shorting plug from program connector.
  • Turn ignition switch OFF.
  • Close all doors, doors should be unlocked.
  • Press the LOCK button on keyless entry remote transmitter that has been programmed into the electronic door lock control processor .

    NOTE: May have to press the button more than once.

    NOTE: For vehicles equipped with anti-theft alarm option, watch the anti-theft indicator, located on the instrument panel while performing this step.

  • Do doors lock and anti-theft indicator lights for 30 seconds?
Yes
GO to A5.

No
GO to A13.

 

A5 UNLOCK DRIVER'S DOOR USING TRANSMITTER

  • Turn ignition switch OFF.
  • Program connector NOT shorted.
  • Doors closed and locked.
  • Press the UNLOCK button on keyless entry remote transmitter.
  • For vehicles with anti-theft alarm option: Open driver door
  • Does door unlock?
Yes
GO to A6.

No
REPLACE electronic door lock control processor .

 

A6 UNLOCK PASSENGER DOOR USING TRANSMITTER

  • Press the UNLOCK button on keyless entry remote transmitter twice (the second press must be within 5 seconds of the first) or if less than 5 seconds since Step A5, press the UNLOCK button on keyless entry remote transmitter once. Turn ignition switch OFF.Program connector (J4) NOT shorted.
  • Do door(s) unlock?
Yes
GO to A7.

No
REPLACE electronic door lock control processor .

 

A7 ACTIVATE THE PERSONAL SECURITY ALARM USING TRANSMITTER 

  • Press the red PANIC button keyless entry remote transmitter . Turn ignition switch OFF.Program connector NOT shorted.
  • Does horn sound and parking lamps flash ON and OFF continuously?
Yes
GO to A8.

No
PERFORM Pinpoint Test F.

 

A8 ENSURE PERSONAL SECURITY ALARM DOES NOT SHUT OFF WITH DIFFERENT TRANSMITTER

NOTE: If only one keyless entry remote transmitter is available, OMIT this step.

  • If more than three minutes have elapsed since Step A7 (if the personal security alarm has shut off) repeat Step A7. Turn ignition switch OFF.Program connector (J4) NOT shorted.
  • If more than one keyless entry remote transmitter is available, press the red PANIC button on a different keyless entry remote transmitter than was used in Step A7.
  • Do horn and parking lamps shut OFF?
Yes
REPLACE electronic door lock control processor .

No
GO to A9.

 

A9 DEACTIVATE PERSONAL SECURITY ALARM USING SAME TRANSMITTER

  • If more than three minutes have elapsed since Step A7 (if the personal security alarm has shut off), repeat Step A7.. Turn ignition switch OFF.Program connector (J4) NOT shorted.
  • Push the red PANIC button on the same keyless entry remote transmitter that was used in Step A7.
  • Do horn and parklamps shut OFF?
Yes
GO to A10.

No
REPLACE electronic door lock control processor .

 

A10 TURN OFF PERSONAL SECURITY ALARM WITH IGNITION SWITCH IN RUN

  • Press the red PANIC button on any keyless entry remote transmitter which has been programmed into the electronic door lock control processor. Program connector NOT shorted
  • Then turn the ignition switch to RUN.
  • Do horn and parking lamps shut OFF with ignition in RUN?
Yes
GO to A11.

No
REPLACE electronic door lock control processor .

 

A11 VERIFY DOOR LOCK USING TRANSMITTER

  • Remove shorting plug from program connector.
  • Turn ignition switch OFF.
  • Close all doors, doors should be unlocked.
  • Press the LOCK button on the keyless entry remote transmitter twice. The second press MUST be within five seconds of the first.
  • Does horn sound and parking lamps flash?
Yes
GO to A12.

No
REPLACE electronic door lock control processor .

 

A12 NO TRANSMISSIONS RECEIVED WITH IGNITION SWITCH IN RUN

  • Ignition switch in RUN. All doors closed and unlockedLuggage compartment door closed and latched
  • Press the UNLOCK button on any keyless entry remote transmitter which has been programmed into the electronic door lock control processor .
  • Do any doors unlock?
Yes
REPLACE electronic door lock control processor .

No
Electronic door lock control system is OK.

 

A13 CHECK ANTENNA/POOR RANGE

  • Open luggage compartment door .
  • Ensure that antenna is connected properly.
  • Disconnect antenna from the electronic door lock control processor antenna plug.
  • Inspect antenna jack for damage, especially to the center pin.
  • Reconnect antenna to electronic door lock control processor (ensure antenna jack is fully seated into electronic door lock control processor antenna plug).
  • Are the antenna and jack in good condition?
Yes
GO to A14.

No
SERVICE as required.

 

A14 TRY ANOTHER TRANSMITTER

  • If more than one keyless entry remote transmitter is available, test the response of all keyless entry remote transmitters for the vehicle.
  • If no other keyless entry remote transmitters are available, go to Step A15.
  • Do other transmitters operate properly?
Yes
REPLACE damaged/worn keyless entry remote transmitter .

No
GO to A15.

 

A15 CHECK FOR SHORTING PLUG/TRANSMITTER PROGRAM MODE

  • Check that shorting plug is not inserted into program connector.
  • Is shorting plug in program connector?
Yes
REMOVE shorting plug from connector.

No
GO to A16 .

 

A16 CHECK FOR INOPERATIVE SHORTING PLUG

  • Disconnect connector (J2) from electronic door lock control processor .
  • Measure continuity between Pin 10 and Pin 15.
  • Is there continuity?
Yes
REPLACE shorting plug.

No
GO to A17 .

 

A17 CHECK PROGRAM "A" SHORT TO GROUND

  • Disconnect electronic door lock control processor connector (J2).
  • Test for continuity between Pin 1 of program connector and ground.
  • Is there continuity?
Yes
SERVICE short to ground in Circuit 808.

No
GO to A18.

 

A18 CHECK PROGRAM "A" SHORT TO BATTERY

  • Test for continuity between Pin 1 of program connector and battery (electronic door lock control processor connector (J2) disconnected).
  • Is there continuity?
Yes
SERVICE short to battery in Circuit 808.

No
GO to A19.

 

A19 CHECK PROGRAM "B" SHORT TO GROUND

  • Test for continuity between Pin 2 of program connector and ground (electronic door lock control processor connector (J2) disconnected).
  • Is there continuity?
Yes
SERVICE short to ground in Circuit 809.

No
GO to A20.

 

A20 CHECK PROGRAM "B" SHORT TO BATTERY

  • Test for continuity between Pin 2 of program connector and battery (electronic door lock control processor connector (J2) disconnected).
  • Is there continuity?
Yes
SERVICE short in battery in Circuit 809.

No
GO to A21.

 

A21 CHECK ELECTRONIC DOOR LOCK CONTROL PROCESSOR PROGRAM "A" INPUT

  • Disconnect electronic door lock control processor connector (J2).
  • Measure the voltage between Pin 15 of connector (J2) and ground.
  • Is VOM reading between 4 volts and 6 volts?
Yes
GO to A22 .

No
REPLACE electronic door lock control processor .

 

A22 CHECK ELECTRONIC DOOR LOCK CONTROL PROCESSOR PROGRAM "B" INPUT

  • Disconnect electronic door lock control processor connector (J2).
  • Measure the voltage between Pin 10 of connector (J2) and ground.
  • Is there continuity?
Yes
GO to A23 .

No
REPLACE electronic door lock control processor .

 

A23 CHECK CONTINUITY OF PROGRAM "A" CIRCUIT

  • Reconnect electronic door lock control processor connector (J2).
  • Measure the voltage between Pin 1 of program connector and ground.
  • Is VOM reading between 4 volts and 6 volts?
Yes
GO to A24.

No
SERVICE open in Circuit 808.

 

A24 CHECK CONTINUITY OF PROGRAM "B" CIRCUIT

  • Reconnect electronic door lock control processor connector (J2).
  • Measure the continuity between Pin 2 of program connector and ground.
  • Is there continuity?
Yes
GO to A25.

No
SERVICE open in Circuit 809.

 

A25 RE-PROGRAM TRANSMITTER

  • Turn ignition switch to RUN.
  • Insert a shorting plug into program connector. This shorting plug connects Program "A" input to Program "B" on the electronic door lock control processor .
  • Do doors lock and unlock?
Yes
GO to A26.

No
GO to D10.

 

A26 STORE TRANSMITTER(S) INTO ELECTRONIC DOOR LOCK CONTROL PROCESSOR MEMORY

  • Turn ignition switch to RUN.
  • Press any button on the keyless entry remote transmitter .

    NOTE: May have to push button more than once.

  • Repeat this sequence for each of the keyless entry remote transmitters (up to four total).
  • For each keyless entry remote transmitter stored:
  • Do all doors lock then unlock?
Yes
GO to A27.

No
GO to A13. If Step A13 has already been performed, REPLACE transmitter batteries and REPEAT Step A26. If still no response, REPLACE electronic door lock control processor.

 

A27 EXIT TRANSMITTER PROGRAM MODE

  • Turn ignition switch OFF.
  • Check that shorting plug has been removed from program connector.
  • Do doors lock and unlock?
Yes
System OK.

No
REPLACE electronic door lock control processor .

  

PINPOINT TEST B: ILLUMINATED ENTRY DOES NOT WORK FROM REMOTE TRANSMITTER

 

B1 CHECK ELECTRONIC DOOR LOCK CONTROL PROCESSOR GROUND

  • Disconnect electronic door lock control processor connectors (J1) and (J2).
  • Check continuity to ground at Pin 5 of connector (J2), and at Pins 1 and 15 of connector (J1).
  • Is there continuity?
Yes
GO to B2.

No
SERVICE open in Circuit 57 for J1, Circuit 397 for J2.

 

B2 CHECK POWER TO ELECTRONIC DOOR LOCK CONTROL PROCESSOR

  • Disconnect electronic door lock control processor connectors (J2) and (J3).
  • Check voltage at Pin 1 of connector (J2) to ground.
  • Check voltage at Pins 14 and 25 of connector (J3) to ground.
  • Is VOM reading higher than 9 volts?
Yes
GO to B3.

No
CHECK and REPLACE fuse. SERVICE open or short in Circuit 517 for J3, 54 for J2.

 

B3 CHECK CONTINUITY TO BATTERY SAVER INPUT

  • Disconnect electronic door lock control processor connector (J3).
  • Check continuity to Circuit 54 at Pins 10 and 23 of connector (J3).
  • Is there continuity?
Yes
GO to B4.

No
SERVICE open in Circuit 54.

 

B4 CHECK BATTERY SAVER INPUT

  • Reconnect electronic door lock control processor connector (J3).
  • Measure the voltage between ground and Pins 10 and 23 of connectors (J3).
  • Is voltage greater than 10 volts?
Yes
GO to B5.

No
SERVICE short in Circuit 54.

 

B5 CHECK BATTERY SAVER OUTPUT

  • With electronic door lock control processor connector (J3) connected, measure the voltage between ground and Pins 11 and 12 of connector (J3).
  • Is voltage greater than 10 volts?
Yes
GO to B6.

No
REPLACE electronic door lock control processor .

 

B6 CHECK IGNITION SWITCH INPUT TO ELECTRONIC DOOR LOCK CONTROL PROCESSOR

  • Check voltage at Pin 6 of electronic door lock control processor connector (J2) with ignition switch in RUN and OFF positions.
  • Is VOM reading 10 volts or more in RUN?
Yes
GO to B7.

No
SERVICE open or short in Circuit 296.

 

B7 CHECK INSTRUMENT PANEL DIMMER SWITCH "ON"

  • With electronic door lock control processor (J3) and (J2) connected, measure voltage between Pin 17 of connector (J3) and ground while the instrument panel dimmer switch is rotated to ON position (switch closed).
  • Is voltage 10 volts or greater?
Yes
GO to B8.

No
SERVICE open switch Circuit 706.

 

B8 CHECK INSTRUMENT PANEL DIMMER SWITCH "OFF"

  • With electronic door lock control processor connectors (J3) and (J2) connected, measure the continuity between Circuit 54 and Pin 10 of connector (J3) while the instrument panel dimmer switch is in the OFF position (switch open).
  • Is there continuity?
Yes
SERVICE shorted switch.

No
GO to B9.

 

B9 CHECK INTERIOR LAMP OUTPUT

  • With electronic door lock control processor connectors (J3) and (J2) connected, turn on instrument panel dimmer switch.
  • Measure voltage between Pins 7 and 19 of connector (J3) and ground.
  • Is voltage 10 volts or more?
Yes
GO to B10.

No
REPLACE electronic door lock control processor .

 

B10 CHECK INPUT TO ELECTRONIC DOOR LOCK CONTROL PROCESSOR FROM INTERIOR LAMP SWITCH

  • For each door handle: Check continuity between Pin 7 of connector (J2) Circuit 465 (W/LB) and ground when door handle is lifted up and when handle is in normal position.
  • Is there continuity with handles lifted and no continuity when handle is in normal position?
Yes
GO to B13.

No
GO to B12 if no continuity when either handle lifted up.
GO to B11 if continuity with both handles in normal position.

 

B11 CHECK COURTESY LAMP SWITCHES

  • For each door with all other doors closed: Disconnect electronic door lock control processor connector (J1).Measure the continuity between Circuit 54 and Pin 7 of connector (J1) with the door open and then closed (dimmer switch off in both cases).
  • Is there continuity with door open and no continuity with door closed (for both doors)? No continuity with door open (for one or both doors)?
Yes
GO to B12.

No
SERVICE/REPLACE damaged/worn courtesy lamp switches and wiring.

 

B12 TURN ON INTERIOR LAMPS WITH A JUMPER WIRE

  • Disconnect electronic door lock control processor connector (J1).
  • Momentarily connect a jumper between Pins 10 and 23 and Pins 7 and 19 of connector (J1).
  • Do lamps come on?
Yes
GO to B13.

No
SERVICE short or open in Circuits 53 or 54. REFER to Section 17-02.

 

B13 CONNECTORS OK

  • Inspect both connectors for loose or corroded pins.
  • Are pins loose or corroded?
Yes
SERVICE as required.

No
REPLACE electronic door lock control processor .

  

PINPOINT TEST C: ANTI-THEFT SYSTEM DOES NOT ARM OR DISARM

 

C1 CHECK CONTINUITY TO DOOR OPEN WARNING LAMP SWITCH

  • Disconnect electronic door lock control processor connector (J2).
  • Test for continuity between Pin 9 of connector (J2) and Circuit 627.
  • Is there continuity?
Yes
GO to C2.

No
SERVICE Circuit 627.

 

C2 CHECK ANTI-THEFT SYSTEM

  • Does system check out?
Yes
REPLACE electronic door lock control processor .

No
SERVICE anti-theft system as required. Refer to Section 13-11.

  

PINPOINT TEST D: PERSONAL SECURITY ALARM DOES NOT WORK FROM REMOTE TRANSMITTER

 

D1 ACTIVATE PARKING LAMPS WITH SWITCH

BEFORE PERFORMING ANY OF THE TESTS IN THIS SECTION, THE BATTERY MUST BE FULLY CHARGED.

  • Turn ON the parking lamps with the lamp switch located on instrument panel .
  • Do parking lamps turn on with switch?
Yes
GO to D2.

No
GO to D5 if parking lamps do not turn ON.
GO to D7 if parking lamps always ON.

 

D2 CHECK PARKING LAMP OUTPUT CIRCUIT CONTINUITY

  • Disconnect electronic door lock control processor connector (J1).
  • Test for continuity between Pin 24 of connector (J1) and Circuit 14 (at parking lamps).
  • Is there continuity?
Yes
GO to D3.

No
SERVICE Circuit 14.

 

D3 CHECK PARKING LAMP INPUT CIRCUIT CONTINUITY

  • Disconnect electronic door lock control processor connector (J1).
  • Test for continuity between Pin 13 of connector (J1) and Circuit 517.
  • Is there continuity?
Yes
GO to D4.

No
SERVICE Circuit 517.

 

D4 CHECK INPUT CIRCUIT BREAKER

  • Measure the voltage between Pin 13 of electronic door lock control processor connector (J1) and ground (connector (J1) disconnected).
  • Is voltage greater than 10 volts?
Yes
REPLACE electronic door lock control processor .

No
SERVICE open or short in Circuit 517.

 

D5 CHECK PARKING LAMPS AND AUTO LAMP RELAY

  • Do parking lamps check OK?
Yes
GO to D6.

No
REPLACE or SERVICE the parking lamps. REFER to Section 17-01.

 

D6 CHECK OUTPUT FUSE

  • Examine fuse 4.
  • Is fuse OK?
Yes
SERVICE open or short in Circuit 14. REPEAT Pinpoint Test A.

No
REPLACE fuse No. 4.

 

D7 CHECK FOR DAMAGED/WORN ELECTRONIC DOOR LOCK CONTROL PROCESSOR CONNECTOR

  • Disconnect electronic door lock control processor connector (J1).
  • Do the parking lamps shut off?
Yes
REPLACE electronic door lock control processor . REPEAT Pinpoint Test A..

No
GO to D8.

 

D8 CHECK LAMP SWITCH ON INSTRUMENT PANEL

  • Disconnect the lamp switch and electronic door lock control processor connector (J1).
  • Do the parking lamps shut off?
Yes
REPLACE the lamp switch.

No
SERVICE short to battery in Circuit 14.

 

D9 ACTIVATE HORN WITH SWITCH

  • Press the horn switch located on the steering wheel.
  • Does horn sound?
Yes
GO to D10.

No
GO to D11 if horn does not sound.

   
    GO to D13 if horn always on.
 

D10 CHECK HORN CIRCUIT CONTINUITY 

  • Disconnect electronic door lock control processor connector (J3).
  • Test for continuity between Pin 26 of connector (J1) and Circuit 6 (the horn relay).
  • Is there continuity?
Yes
REPLACE electronic door lock control processor .

No
SERVICE Circuit 6.

 

D11 CHECK HORN AND HORN RELAY

  • Does horn and horn relay work?
Yes
GO to D12.

No
REPLACE or SERVICE the horn or horn relay.

 

D12 CHECK OUTPUT FUSE

  • Examine fuse 10.
  • Is fuse OK?
Yes
SERVICE open or short in Circuit 6.

No
REPLACE fuse.

 

D13 CHECK FOR DAMAGED/WORN ELECTRONIC DOOR LOCK CONTROL PROCESSOR CONNECTOR

  • Disconnect electronic door lock control processor connector (J1).
  • Does the horn shut off?
Yes
REPLACE electronic door lock control processor .

No
GO to D14.

 

D14 CHECK HORN SWITCH ON STEERING WHEEL

  • Disconnect the horn switch and electronic door lock control processor connector (J1).
  • Does the horn shut off?
Yes
REPLACE horn switch.

No
SERVICE short to ground in Circuit 6 or SERVICE the horn relay circuitry (Section 13-06).

 

D15 TEST FOR FALSE ALARM

  • When the alarm activates falsely, turn the ignition switch to the RUN/ACC position.
  • Does alarm continue to sound?
Yes
REFER to Section 13-11.

No
REPLACE electronic door lock control processor .

  

PINPOINT TEST E: COURTESY LAMPS DO NOT TURN OFF IF LEFT ON

 

E1 LOCK SYSTEM TEST

  • Unlock door using keyless entry remote transmitter .
  • Observe lighting for 2 minutes.
  • Do courtesy lamps turn off after 2 minutes?
Yes
REFER to Section 17-02 for courtesy lamp diagnosis.

No
GO to Pinpoint Test B.

  

PINPOINT TEST F: LUGGAGE COMPARTMENT DOOR UNLOCK WILL NOT UNLOCK

 

F1 UNLOCK LUGGAGE COMPARTMENT DOOR WITH LUGGAGE COMPARTMENT REMOTE CONTROL LOCK SWITCH

  • Turn ignition switch to RUN.
  • Press the luggage compartment remote control lock switch on the console.
  • Does luggage compartment unlock?
Yes
GO to F2.

No
GO to F3.

 

F2 CHECK LUGGAGE COMPARTMENT REMOTE CONTROL LOCK SWITCH CIRCUIT CONTINUITY

  • Disconnect electronic door lock control processor connector (J3).
  • Test for continuity between Pins 9 and 22 of connector (J3) and the luggage compartment door lock solenoid.
  • Is there continuity?
Yes
REPLACE electronic door lock control processor .

No
SERVICE open in Circuit 84.

 

F3 CHECK LUGGAGE COMPARTMENT DOOR LATCH SOLENOID

  • Is luggage compartment door latch operational?
Yes
GO to F4.

No
REPLACE luggage compartment door latch .

 

F4 CHECK FUSE

  • Examine fuse 6.
  • Is fuse OK?
Yes
SERVICE open or short in Circuit 84.

No
GO to F5.

 

F5 CHECK FOR SHORTED ELECTRONIC DOOR LOCK CONTROL PROCESSOR

  • Disconnect electronic door lock control processor connector (J1).
  • Does luggage compartment door lock?
Yes
REPLACE electronic door lock control processor .

No
GO to F6.

 

F6 CHECK LUGGAGE COMPARTMENT REMOTE CONTROL LOCK SWITCH IN CONSOLE

  • Disconnect luggage compartment remote control lock switch and electronic door lock control processor connector.
  • Does luggage compartment door lock?
Yes
REPLACE luggage compartment remote control lock switch .

No
SERVICE short to battery in Circuit 84.