Test Hd: Misfire Detection Monitor: Testing

1) For KOER & Continuous Memory Only DTC P0300-P0310, & Continuous Memory DTC P0316: Check For Adaptive Fuel Monitor & HO2S Continuous Memory DTCs
DTC P0300 indicates multiple cylinders are misfiring or the PCM cannot identify which cylinder is misfiring. Possible causes are:
- Camshaft Position Sensor.
- Low fuel: less than 1/8 tank.
- Stuck open EGR valve.
- Blocked EGR passages.
DTCs P0301-P0310 are designed to monitor engine misfire and identify the specific cylinder in which the misfire has occurred. Misfire is defined as lack of combustion in a cylinder due to absence of spark, poor fuel metering, poor compression, or any other cause. Possible causes are:
- Ignition system.
- Fuel injectors.
- Running out of fuel.
- EVAP canister purge valve.
- Fuel pressure.
- Evaporative emission system.
- Base engine.
Check for other non-misfire Continuous Memory DTCs which could cause misfire DTC. If DTC P0136, P0156, P0171, P0172, P0175, P1130 or P1150 is present, go to step 3). If specified DTCs are not present, go to next step.

2) Check For Other Non-Misfire Continuous Memory DTCs

Check for other non-misfire Continuous Memory DTCs which could cause misfire DTC. If any other Continuous Memory DTCs are present, disregard misfire DTCs at this time and service other Continuous Memory DTC as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no other Continuous Memory DTCs are present, go to next step.

3) Check For KOEO DTCs

Check for any KOEO DTCs which could cause misfire DTC. If any KOEO DTCs are present, service KOEO DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no KOEO DTCs are present, check spark plugs and spark plug wires. Go to TEST JB, step 1). If spark plugs and spark plug wires are okay, go to next step.

4) Check For KOER DTCs

If KOER DTC P1131, P1132, P1137, P1138, P1151, P1152, P1157 or P1158 is present, go to step 8). If any other KOER DTCs are present, disregard misfire DTCs at this time and service DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no KOER DTCs are present and a misfire is present, go to step 6) (vehicles with DPF EGR system), or go to step 7) (vehicles without DPF EGR system). For sensor application, see SENSORS CONNECTED TO VREF CIRCUIT table. If misfire concern is intermittent, use FREEZE FRAME DATA MODE and go to TEST Z, step 1) . If no KOER DTCs are present and no misfire is present, go to step 7).
NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 4) to step 6). No test procedures have been omitted.

6) Check/Compare PID Values

Connect scan tool to Data Link Connector (DLC). Start engine and allow to idle. Ensure engine is warmed to normal operating temperature. Using scan tool, access and record DPFEGR PID voltage reading while engine is running (KOER). Turn ignition switch to OFF position. Turn ignition switch to ON position. Select and record DPFEGR PID voltage reading while engine is off (KOEO). Compare KOEO and KOER DPFEGR PID readings. If DPFEGR PID voltage readings are within .15 volt of each other, go to next step. If DPFEGR PID voltage readings are not within .15 volt of each other, go to TEST HE, step 100).

NOTE: DTCs may be stored during testing and will need to be cleared following repair.

7) EGR Restriction/Flow Test
Record and clear DTCs. Disconnect and plug EGR valve vacuum hose. Perform DRIVE CYCLES . Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed. If misfire DTC is still present, go to next step. If misfire DTC is no longer present, inspect EGR passage and intake port for blockage and repair as necessary.

8) Check Injector Driver PIDs (INJ1F-INJ10F)

Turn ignition switch to ON position. Using scan tool, access and record appropriate injector PID (INJ1F-INJ10F) for suspect injector. If injector PID value indicates YES, go to next step. If injector PID value indicates NO, go to step 10).

9) Check Fuel Injector & Harness For Open

Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure resistance between suspect fuel injector signal and VPWR circuits at PCM harness connector. See Figure. See PCM FUEL INJECTOR, PWR GND & VPWR CIRCUIT TERMINAL IDENTIFICATION table for PCM injector terminal identification. Fuel injector resistance should be within specification. See Figure. If fuel injector resistance is within specification, replace PCM. If fuel injector resistance is not within specification, go to TEST H, step 57).

WARNING: Always refer to safety procedures to reduce possibility of injury. See FUEL SYSTEM SAFETY PRECAUTIONS .

10) Check Fuel Pressure
Turn ignition switch to OFF position. Release fuel pressure. See FUEL SYSTEM PRESSURE RELEASE procedure in appropriate REMOVAL & INSTALLATION article. Install fuel pressure gauge to Schrader valve on fuel rail. Start engine and allow to idle. Record initial fuel pressure gauge reading. Increase engine speed to 2500 RPM and maintain for one minute. Record final fuel pressure gauge reading. Compare fuel pressure gauge readings to specification. See FUEL PRESSURE SPECIFICATIONS . If fuel pressure gauge readings are within specification, go to next step. If fuel pressure gauge readings are not within specification, check and repair fuel system as necessary.

11) Check Ability Of Fuel System To Hold Fuel Pressure

Start engine and allow to idle. Record fuel pressure gauge reading. Increase engine speed to 2500 RPM and maintain for one minute. Check for fuel leaking from around fuel injectors, fuel pressure regulator and fuel lines. Repair as necessary. If fuel pressure gauge reading remains within 5 psi (34 kPa) of specification for one minute, go to step 12). If fuel pressure gauge reading does not remain within 5 psi (34 kPa) of specification for one minute, check fuel system for faults and repair as necessary.

WARNING: Always refer to safety procedures to reduce possibility of injury. See FUEL SYSTEM SAFETY PRECAUTIONS .

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 12) to step 20). No test procedures have been omitted.

12) Check Fuel Injector Flow & Leakage
Turn ignition switch to OFF position. Use Rotunda fuel injector tester from Kit (113-00114) to flow test fuel injectors. Follow injector tester instructions. Fuel injector flow rate should be within specification. If flow rate for each fuel injector is within specification, fuel delivery system is not the likely cause of misfire DTC. Go to step 20). If flow rate for any fuel injector is not within specification, clean or replace defective fuel injector(s).

20) Check Vacuum System

Inspect all vacuum hoses for kinks or damage. Ensure all vacuum connections are clean and tight. Repair as necessary and perform DRIVE CYCLES . Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If vacuum system is okay, go to next step.

21) Check Crankshaft Damper & Pulley Assembly

On models equipped with crankshaft pulley-mounted pulse ring, check crank pulley and pulse ring for damage or looseness. On models not equipped with crankshaft pulley-mounted pulse ring, remove front cover if necessary. Check crank pulley and pulse ring for damage or looseness. On all models, repair as necessary and disconnect battery for 5 minutes to allow PCM to learn new data. If no faults are found, go to next step.

NOTE: The MISFIRE MONITOR can be affected by evaporative emission system.

22) Check Evaporative Emission System
Inspect carbon (EVAP) canister for fuel saturation. Replace carbon (EVAP) canister if liquid fuel is present. Perform DRIVE CYCLES . Ensure MISFIRE & FUEL MONITOR PROCEDURES are performed to verify repair. If carbon (EVAP) canister is okay, go to next step.

23) Pressure Test Evaporative Emission System

Using Rotunda Evaporative Emission System Tester (134-00056), pressure test evaporative system starting at EVAP service port (if equipped), then at fuel filler cap. Follow evaporative emission system tester instructions. If evaporative emission system holds pressure, go to next step. If system does not hold pressure, isolate fault and repair as necessary.

24) Check Vacuum In Evaporative Emission System

Inspect vacuum hoses between engine and carbon canister for restrictions or damage. Ensure all vacuum connections are clean and tight. Check for fuel tank vent system blockage. Repair as necessary. If no faults are found, go to step 26).
NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 24) to step 26). No test procedures have been omitted.

26) Check EVAP Canister Purge Valve Housing For Leaks

Turn ignition switch to OFF position. Ensure EVAP CPV is connected. Connect hand-held vacuum pump to fuel vapor port from EVAP canister at EVAP CPV and apply 16 in. Hg (53 kPa). If EVAP CPV holds vacuum at room temperature, go to next step. If EVAP CPV does not hold vacuum at room temperature, replace EVAP CPV.

27) Check For Filter Contamination

Disconnect hose from vacuum input port of EVAP CPV. Connect vacuum pump to EVAP CPV vacuum input port and apply 10-15 in. Hg (48-52 kPa). If EVAP CPV holds vacuum or EVAP CPV is very slow to release vacuum, service EVAP CPV filter. If unable to clean or remove blockage to filter, replace EVAP CPV. If vacuum is not held as specified, remove vacuum pump, reconnect all components and go to step 29).
NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 27) to step 29). No test procedures have been omitted.

NOTE: Engine temperature may affect results of this test.

29) Check Engine Mechanical Condition
This test step will determine if there are any base engine concerns that may have caused Misfire DTC or drive concern. Perform the following in order to evaluate base engine integrity:
- Engine compression and leakdown tests.
- Valve train analysis.
- Check positive crankcase ventilation system.
- Check for possible leaks.
Repair as necessary. If no faults can be found, misfire DTC is intermittent. Go to TEST Z, step 1) to check intermittent ignition system concern. If ignition system is okay, go to next step.

30) Check For Additional Misfire DTCs

DTC P0300 indicates multiple cylinders are misfiring or PCM cannot identify which cylinder is misfiring. If any other misfire DTCs are present, return to step 1). If no other misfire DTCs are present, go to next step.

31) Check For Other Continuous Memory DTCs

If any other Continuous Memory DTCs are present, service DTCs as necessary. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no other Continuous Memory DTCs are present, go to next step.

NOTE: Hall Effect type Camshaft Position (CMP) sensor has a 3-pin connector. Variable reluctance type CMP sensor has a 2-pin connector.

NOTE: A break in step numbering sequence occurs at this point. Procedure skips from step 32) to step 40). No test procedures have been omitted.

32) Check/Compare PID Values
Connect scan tool to Data Link Connector (DLC). Start engine and allow to idle. Ensure engine is warmed to normal operating temperature. Using scan tool, access and record DPFEGR PID voltage reading while engine is running. Turn ignition switch to OFF position. Turn ignition switch to ON position, with engine off. Select and record DPFEGR PID voltage reading while engine is off. Compare KOEO and KOER DPFEGR PID voltage readings. If DPFEGR PID voltage readings are within .15 volt of each other, go to step 40) (vehicles with Hall Effect CMP sensor), or go to step 41) (vehicles with variable reluctance CMP sensor). If DPFEGR PID voltage is not as specified, go to TEST HE, step 100).

NOTE: For additional testing information, see DIAGNOSTIC AIDS .

40) For Continuous Memory Only DTC P1336: Check Hall Effect CMP Sensor Output, PCM Disconnected
This fault indicates CKP or CMP sensor input signal to PCM was erratic. Possible causes for this fault are:
- Faulty Powertrain Control Module (PCM)
- Faulty Camshaft Position (CMP) Or Crankshaft Position (CKP) Sensor
- Engine Mechanical Concern
- Harness Concerns
Turn ignition switch to OFF position. Disconnect PCM connector(s). Inspect connector for loose, damaged or corroded terminals. Repair as necessary. Using a DVOM, measure voltage between CMP and PWR GND circuits at PCM harness connector. See WIRING DIAGRAMS . See PCM CONNECTOR IDENTIFICATION . Use remote starter switch and bump engine in short bursts for at least 10 revolutions. If voltage switches between less than 2 volts and more than 8 volts, check CMP sensor for correct installation and synchronization (if necessary). See IGNITION SYSTEMS in appropriate REMOVAL & INSTALLATION article. If CMP sensor is correctly installed and synchronized, replace PCM. If voltage does not switch between less than 2 volts and more than 8 volts, replace CMP sensor.

NOTE: For additional testing information, see DIAGNOSTIC AIDS .

NOTE: DTC P1309 indicates Misfire Detection Monitor is not enabled.

41) For Continuous Memory Only DTC P1309: Check Variable Reluctance CMP Sensor Output, PCM Connected
This fault indicates MISFIRE MONITOR was disabled due to CMP sensor input signal to PCM malfunction. Possible causes for this fault are:
- Faulty Camshaft Position (CMP) Sensor
- Faulty Powertrain Control Module (PCM)
- Faulty Crankshaft Position (CKP), Engine Coolant Temperature (ECT) Or Mass Air Flow (MAF) Sensor
Turn ignition and all accessories off. Ensure PCM is connected. Using a DVOM, backprobe and measure AC voltage between CMP and PWR GND circuits at PCM harness connector. See WIRING DIAGRAMS . See PCM CONNECTOR IDENTIFICATION . Start engine and vary engine speed. If AC voltage varies more than .1 volt, check CMP sensor for correct installation. If CMP sensor is correctly installed, replace PCM. If AC voltage does not vary more than .1 volt, replace CMP sensor.

NOTE: For additional testing information, see DIAGNOSTIC AIDS .

42) For Continuous Memory Only DTC P0315: Check Physical Condition Of Crankshaft Pulse Wheel
DTC P0315 is set when PCM is unable to learn and correct for mechanical variations in Crankshaft Pulse Wheel tooth spacing (allowable correction tolerances have been exceeded). Possible causes for this fault are:
- Faulty Crankshaft Position Pulse Wheel Teeth
- Faulty Crankshaft Position (CKP) Sensor
Inspect crankshaft pulse wheel for damaged teeth or for excessive wobble. Inspect for a loose crankshaft pulse wheel or damaged CKP sensor. Repair as necessary. If CKP sensor and crankshaft pulse wheel are okay, inspect crankshaft for damage. See appropriate article in ENGINES. Disconnect battery for 5 minutes to allow PCM to learn new data.