HD: Misfire Detection Monitor

HD: Introduction See: HD: Misfire Detection Monitor - Introduction

HD1 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

• GO to HD3

.

No

• GO to HD2

.

HD2 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

• ADDRESS the next Continuous Memory DTC. DISREGARD Misfire DTC at this time. GO to Section 4 for Powertrain Diagnostic Trouble Code (DTC) Charts See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions.

No

• GO to HD3

.

HD3 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

• GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions, and PROCEED as required.

No

• GO to JB1 See: JB: Secondary Ignition - Pinpoint Test

to evaluate spark plugs and secondary wires. If OK, GO to HD4
.

HD4 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

• If DTCs P1132, P1138, P1152, P1158, P1131, P1137, P1151 or P1157 are present, GO to HD8

.

• All others: GO to Section 4, Powertrain Diagnostic Trouble Code (DTC) Charts See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions, and PROCEED as required.

No

• If Misfire is present:

Those with DPFEGR Systems, GO to HD6
.

• All others: GO to HD7

.

• If Intermittent:

GO to Section 2, Diagnostic Methods See: SECTION 2: Diagnostic Methods\Diagnostic Methods for Freeze Frame Data and GO to Z1 See: Z: Intermittent - Pinpoint Test
for Intermittent Diagnosis.

• If OK, GO to HD7

.

HD6 CHECK/COMPARE PID VALUES

Note: If application does not have an EGR system, proceed to HD8.

• 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

• KEY OFF. GO to HD7

.

No

• KEY OFF. GO to HE100 See: Pinpoint Tests\HE: Exhaust Gas Recirculation (EGR) Systems - Pinpoint Test

.

HD7 EGR RESTRICTION/FLOW TEST

Note: DTCs may be induced and will need to be cleared at end of testing.

• Record and clear codes.
• Disconnect vacuum line at EGR valve and plug the vacuum line.
• Complete Misfire Monitor Drive Cycle.

Is Misfire code still present?
Yes

• GO to HD8

.

No

• REFER to Engine, for EGR and intake port inspection.

HD8 CHECK INJECTOR DRIVER PIDS INJ1F THRU INJ10F

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

Is the PID status Yes?
Yes

• GO to HD9

.

No

• 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 (GO to Pinpoint Test H See: H: Fuel Control - Introduction to refer to the injector connector chart).
• GO to Pinpoint Test HC See: HC: Fuel Delivery System - Introduction Refer to the Fuel Delivery System Test Information Chart (at the beginning of the pinpoint test) for injector resistance values.

Is the resistance value(s) within specification?
Yes

• REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM).

No

• GO to H62 See: H: Fuel Control - Pinpoint Test

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.

Is the fuel pressure at the specified pressure( GO to Pinpoint Test HC See: HC: Fuel Delivery System - Introduction to use the fuel pressure chart)?
Yes

• KEY OFF. GO to HD11

.

No

• REFER to Fuel Delivery and Air Induction.

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 34 kPa (5 psi) for 60 seconds?
Yes

• KEY OFF. GO to HD12

.

No

• REFER to Fuel Delivery and Air Induction to determine which area within the Fuel Delivery System is at fault.

HD12 CHECK FUEL INJECTOR FOR FLOW AND LEAKAGE

• GO to Pinpoint Test HC See: HC: Fuel Delivery System - Introduction to refer to the Warning, Caution, and Handling, 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

• Fuel delivery system is not likely to have caused the Misfire DTC. GO to HD20

to diagnose the vacuum system.

No

• REPLACE or CLEAN the inoperative fuel injector(s) as required. COMPLETE

Misfire Monitor Repair Verification Drive Cycle(REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles).

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

• GO to HD21

.

No

• REPAIR the vacuum system. COMPLETE Misfire Monitor Repair Verification Drive Cycle(REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles).

HD21 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

• 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(REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles).

No

• GO to HD22

.

HD22 CHECK EVAPORATIVE EMISSION SYSTEM

The Misfire Monitor can be influenced by Evaporative Emission System. The next five 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

• REPLACE EVAP. COMPLETE Misfire Monitor Repair Verification Drive Cycle(REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles).

No

• CHECK fuel tank vent system. GO to HD23

.

HD23 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

• GO to HD24

.

No

• REPAIR as necessary. COMPLETE Misfire Monitor Repair Verification Drive Cycle(REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles).

HD24 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

• REPLACE damaged vacuum hoses, or REMOVE blockage/restrictions. COMPLETE

Misfire Monitor Repair Verification Drive Cycle(REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles).

No

• GO to HD26

.

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

• GO to HD27

.

No

• 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

• 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.

No

• REMOVE vacuum pump. RECONNECT all components. GO to HD29

.

HD29 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.
Note: Engine temperature may affect results.
Perform the following tests in order to evaluate base engine integrity:

• Perform Engine Compression and leakdown tests.
• Perform Valve Train analysis.
• Check Positive Crankcase Ventilation System.
• Check possible leakage points.
• Refer to Engine System-General Information.

Is any service required?
Yes

• REFER to Engine System, General Information.

No

• The cause of the Misfire DTC is intermittent. To diagnose the Ignition System, GO to Z1 See: Z: Intermittent - Pinpoint Test

.

• If OK, GO to HD30

.

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

• GO to HD1

.

No

• GO to HD31

.

HD31 CHECK FOR OTHER CONTINUOUS MEMORY DTCS

Are other Continuous Memory DTCs present?
Yes

• GO to Section 4 for Powertrain Diagnostic Trouble Code (DTC) Charts See: A L L Diagnostic Trouble Codes ( DTC )\Testing and Inspection\Diagnostic Trouble Code Descriptions. PROCEED as required.

No

• 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.
• 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

• KEY OFF. Vehicles with VRS type CMP, GO to HD41

.

• KEY OFF. Vehicles with hall effect type CMP, GO to HD40

.

No

• KEY OFF. GO to HE100 See: Pinpoint Tests\HE: Exhaust Gas Recirculation (EGR) Systems - Pinpoint Test

.

HD40 CHECK CMP SENSOR OUTPUT - PCM DISCONNECTED

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

• 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, Computers and Control Systems. If the CMP is installed properly, REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM). RESTORE vehicle. COMPLETE Misfire Monitor Repair Verification Drive Cycle (REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles). RERUN Quick Test.

No

• REPLACE CMP sensor. RESTORE vehicle. COMPLETE Misfire Monitor Repair Verification Drive Cycle(REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles). RERUN Quick Test.

HD41 CHECK CMP SENSOR OUTPUT - PCM CONNECTED

• 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

• VERIFY the correct installation by referring to Computers and Control Systems. If CMP is installed

properly, REPLACE PCM (refer to Section 2, Flash Electrically Erasable Programmable Read Only Memory (EEPROM) See: Programming and Relearning\Flash Electrically Eraseable Programmable Read Only Memory - Flash EEPROM). COMPLETE Misfire Monitor Repair Verification Drive Cycle (REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles). RERUN Quick Test.

No

• REPLACE CMP sensor. COMPLETE Misfire Monitor Repair Verification Drive Cycle (REFER to Section 2, Drive Cycles See: SECTION 2: Diagnostic Methods\Drive Cycles).