On Board Diagnostics II PCED

1999 PCED On Board Diagnostics II

SECTION 5: Pinpoint Tests

HD: Misfire Detection Monitor

HD1 DTC P0301-P0310: CHECK FOR NO LOW FUEL

Note: Running out of fuel can turn on the MIL and possibly store a Continuous Misfire DTC.

Has the vehicle recently run out of fuel?

Yes	No
OBD II system OK. COMPLETE PCM Reset to clear DTCs.	GO to HD2 .

HD2 CHECK DAMPER AND PULLEY ASSEMBLY

Note: This Pinpoint Test Step is for engines that have damper-mounted pulse rings. Remove the front cover if necessary to observe the crank pulley.

Observe the crank pulley for wobble.
Examine the EI pulse ring fastened to the harmonic fastener.

Does the crank pulley wobble or is the pulse ring loose or damaged?

Yes	No
DISCONNECT battery for 5 minutes to allow PCM to learn new data, due to the old pulse ring. REPLACE the pulley or damper assembly. COMPLETE Misfire Monitor Repair Verification Drive Cycle.	GO to HD3 .

HD3 CHECK FOR ADAPTIVE FUEL MONITOR AND HO2S CONTINUOUS MEMORY DTCS

Note: The following is a list of non-misfire DTCs to look for in the Continuous Memory.

P0136, P0156
P0171, P0172, P0175
P1130, P1150

Are any of the DTCs listed above present?

Yes	No
GO to HD5 .	GO to HD4 .

HD4 CHECK FOR OTHER NON-MISFIRE CONTINUOUS MEMORY DTCS

Note: Check for other non-misfire Continuous Memory DTCs which could cause the misfire DTC.

Are other non-misfire Continuous Memory DTCs present?

Yes	No
ADDRESS the next Continuous Memory DTC. DISREGARD Misfire DTC at this time. GO to Section 4 for Powertrain DTC Charts.	GO to HD5 .

HD5 CHECK FOR KEY ON ENGINE OFF (KOEO) DTCS

Check for any key on, engine off DTCs which could cause the Misfire DTC.

Are any key on, engine off DTCs displayed on the Scan Tool?

Yes	No
GO to Section 4 , Powertrain DTC Charts, and PROCEED as required.	GO to JB1 to evaluate spark plugs and secondary wires. If OK, GO to HD6

HD6 CHECK FOR OTHER KEY ON ENGINE RUNNING DTCS

Note: Check for any other key on, engine running DTCs which can cause the Misfire DTC.

Are any additional key on, engine running DTCs displayed on the Scan Tool?

Yes	No
If DTCs P1132, P1138, P1152, P1158, P1131, P1137, P1151 or P1157 are present, GO to HD8 . All others: GO to Section 4 , Powertrain DTC Charts, and PROCEED as required.	Vehicles with D.P.F. EGR Systems: GO to HD7 . All others: GO to HD8 .

HD7 CHECK/COMPARE PID VALUES

Start engine and warm to normal operating temperature.
Access DPFEGR PID.
Record DPFEGR PID value.
Key off.
Key on, engine off.
Access DPFEGR.
Compare key on, engine off and engine running PID values.

Was engine running PID value within 0.15 volt of key on, engine off value?

Yes	No
KEY OFF. GO to HD8 .	KEY OFF. Go to Pinpoint Test Step HE100 .

HD8 CHECK INJECTOR DRIVER PIDS INJ1F THRU INJ10F

Key on, engine off.
Access appropriate PID(s) for the suspect fuel injector.

Is the PID status Yes?

Yes	No
GO to HD9 .	GO to HD10 .

HD9 CHECK FUEL INJECTOR(S) AND HARNESS FOR OPEN

Disconnect PCM.
Measure resistance of fuel injector and harness circuit between the fuel injector and VPWR circuits at the fuel injector harness connector (Refer to the injector connector chart in Pinpoint Test H).

Is the resistance between 11.0-18.0 ohms?

Yes	No
REPLACE PCM (refer to Section 2 , Flash EEPROM).	GO to Pinpoint Test Step H57 to diagnose fuel injectors.

HD10 CHECK FUEL PRESSURE

WARNING: THE FUEL SYSTEM WILL REMAIN PRESSURIZED WHEN ENGINE IS NOT RUNNING. TO PREVENT INJURY OR FIRE, USE CAUTION WHILE WORKING ON THE FUEL SYSTEM.

Install fuel pressure gauge.
Start and run engine at idle. Record fuel pressure.
Increase engine speed to 2500 rpm and maintain for one minute. Note and compare fuel pressure.

Vehicle	kPa	psi
Contour/Mystique, Cougar 2.5L	310-415	45-60
Continental	310-415	45-60
Escort/Tracer, Mustang LS6/LS8	240-380	35-55
Ranger	386-496	56-72
Ranger (Flex Fuel)	380-517	55-75
All Others	207-310	30-45

Is the fuel pressure at the specified pressure (use the fuel pressure chart)?

Yes	No
KEY OFF. GO to HD11 .	GO to Fuel System General Information, Section 310-00 in the Workshop Manual.

HD11 CHECK ABILITY OF FUEL SYSTEM TO HOLD FUEL PRESSURE

Start and run engine at idle. Note fuel pressure.
Increase engine speed to 2500 rpm and maintain for one minute.
Look for fuel leaking at the fuel injector O-ring, fuel pressure regulator and the fuel lines to the fuel charging assembly.

Did fuel pressure remain at specification within 16.5 kPa (5 psi) for 60 seconds?

Yes	No
KEY OFF. GO to HD12 .	GO to Fuel System General Information, Section 310-00 in the Workshop Manual to determine which area within the Fuel Delivery System is at fault.

HD12 CHECK FUEL INJECTOR FOR FLOW AND LEAKAGE

Refer to Warning, Caution and Handling at the beginning of Pinpoint Test HC to avoid fuel spillage and injury.
Verify that the flow rate for each fuel injector is within specification using Injector Flow Tester.

Is flow rate for each fuel injector within specification?

Yes	No
Fuel delivery system is not likely to have caused the Misfire DTC. GO to HD20 to diagnose the vacuum system.	REPLACE or CLEAN the inoperative fuel injector(s) as required. COMPLETE Misfire Monitor Repair Verification Drive Cycle.

HD20 CHECK VACUUM SYSTEM

Note: Some vacuum leaks can be heard.

Inspect all vacuum lines for damage, such as pinched lines, cracks, proper routing and assembly.

Is the vehicle vacuum system OK?

Yes	No
GO to HD21 .	REPAIR the vacuum system. COMPLETE Misfire Monitor Repair Verification Drive Cycle.

HD21 CHECK EVAPORATIVE EMISSION SYSTEM

The Misfire Monitor can be influenced by Evaporative Emission System. The next four Pinpoint Test steps will diagnose the Evaporative Emission System.

Check the EVAP canister for fuel saturation.

Is there an excess amount of liquid fuel present in the fuel vapor storage canister?

Yes	No
REPLACE EVAP. COMPLETE Misfire Monitor Repair Verification Drive Cycle.	CHECK fuel tank vent system. GO to HD22 .

HD22 PRESSURE TEST EVAPORATIVE EMISSION SYSTEM

Pressure test EVAP emission system.
Install Rotunda Evaporative Emission System Tester 134-00056 or equivalent first at the EVAP SERVICE port, if equipped, then at the fuel filler cap.
Follow test instructions from the Tester Kit.

Is evaporative emission system holding pressure?

Yes	No
GO to HD23 .	REPAIR as necessary. COMPLETE Misfire Monitor Repair Verification Drive Cycle.

HD23 CHECK VACUUM IN EVAPORATIVE EMISSION SYSTEM

Check for blockage/restrictions or cut hoses between engine vacuum port and EVAP canister.
Check for blockage in fuel tank vent system.

Is there a fault indicated?

Yes	No
REPLACE damaged vacuum hoses, or REMOVE blockage/restrictions. COMPLETE Misfire Monitor Repair Verification Drive Cycle.	GO to HD26 .

HD25 CHECK FOR BASE ENGINE CONCERNS

This Pinpoint Test step will determine if there are any base engine concerns that may have caused the Misfire DTC or drive concern.

Perform the following tests in order to evaluate base engine integrity:

Perform an Engine Compression test.
Perform Dynamic Valve Train analysis.
Check Positive Crankcase Ventilation System.
Check possible leakage points.
Refer to Engine System-General Information, Section 303-00 in the Workshop Manual for all of the above.

Is any service required?

Yes	No
GO to Engine System, General Information, Section 303-00 in the Workshop Manual, Diagnosis and Testing, to make repairs.	The cause of the Misfire DTC is intermittent. To diagnose the Ignition System, GO to the Intermittent Ignition procedure in Pinpoint Test Step Z50 . FOLLOW Instructions for using the Rotunda Electronic Ignition System, (Distributor/less Ignition System Tester (DIST)) tool.

HD26 CHECK OF EVAP CANISTER PURGE VALVE HOUSING LEAKS

EVAP canister purge valve electrically connected.
Install a hand vacuum pump to the fuel vapor port from EVAP canister on the EVAP canister purge valve vacuum at line.
Apply 53 kPa (16 in-Hg) of vacuum with the vacuum pump.

Does the EVAP canister purge valve hold vacuum at room temperature?

Yes	No
Go to HD27 .	REMOVE vacuum pump. REPLACE damaged EVAP canister purge valve. COMPLETE PCM Reset to clear DTCs.

HD27 CHECK FOR FILTER CONTAMINATION ON DAMAGE EVAP CANISTER PURGE VALVE

Vacuum line from input vacuum port to intake manifold on the EVAP canister purge valve (control vacuum solenoid part of valve) is removed.
Install a hand held vacuum pump to the open input vacuum port on the EVAP canister purge valve.
Apply 48-52 kPa (10-15 in-Hg) of vacuum to the EVAP canister purge valve.

Does the EVAP canister purge valve hold vacuum or is the valve very slow to release vacuum to atmosphere?

Yes	No
REPAIR EVAP canister purge valve filter. If unable to clean filter or REMOVE blockage to filter, REPLACE EVAP canister purge valve. COMPLETE Misfire Monitor Repair Verification Drive Cycle.	REMOVE vacuum pump. RECONNECT all components. GO to HD25 .

HD30 CHECK FOR ADDITIONAL MISFIRE DTCS

Diagnostic Trouble Code P0300 indicates multiple cylinders are misfiring or PCM cannot identify which cylinder is misfiring.

Are any other misfire DTCs present?

Yes	No
GO to HD1 .	GO to HD31 .

HD31 CHECK FOR OTHER CONTINUOUS MEMORY DTCS

Are other Continuous Memory DTCs present?

Yes	No
GO to Section 4 for Powertrain DTC Charts. PROCEED as required.	GO to HD32 .

HD32 CHECK/COMPARE PID VALUES

Start engine and warm to normal operating temperature.
Access DPFEGR PID.
Record PID value.
Key off.
Key on, engine off.
Access DPFEGR.
Start engine, let idle.
Compare key on, engine off and engine running PID values.

Is engine running DPFEGR PID value within 0.15 volt of key on, engine off value?

Yes	No
KEY OFF. Vehicles with VRS type CMP, GO to HD41 . KEY OFF. Vehicles with hall effect type CMP, GO to HD40 .	KEY OFF. GO to Pinpoint Test Step HE100 .

HD40 CHECK CMP SENSOR OUTPUT

Diagnostic Trouble Code (DTC) P1309 indicates Misfire Detection Monitor is not enabled.

Disconnect PCM.
Connect digital multimeter.
Measure voltage between CMP and PWR GND circuits at the PCM harness connector.
Bump engine in short burst with the starter without starting engine for at least 10 engine revolutions.

Does digital multimeter reading switch between low (less than 2.0 volts DC) and high (greater than 8.0 volts DC)?

Yes	No
Note: A Hall effect type CMP sensor that is installed out of synchronization will produce a DTC. VERIFY the correct installation by referring to the Electronic Engine Controls, Section 303-14 in the Workshop Manual. If the CMP is installed properly, REPLACE PCM (refer to Section 2 , Flash EEPROM). RESTORE vehicle. RERUN Quick Test.	REPLACE CMP sensor. RESTORE vehicle. COMPLETE Misfire Monitor Repair Verification Drive Cycle. RERUN Quick Test.

HD41 CHECK CMP SENSOR OUTPUT

Connect PCM.
Connect digital multimeter.
Start engine and vary engine RPM.
Measure voltage between CMP and PWR GND circuits at the PCM harness connector.

Does AC voltage vary greater than 0.1 volt AC?

Yes	No
VERIFY the correct installation by referring to the Electronic Engine Controls, Section 303-14 in the Workshop Manual. If CMP is installed properly, REPLACE PCM (refer to Section 2 , Flash EEPROM).	REPLACE CMP sensor. COMPLETE Misfire Monitor Repair Verification Drive Cycle.