Diagnostic Procedures
- If QUICK TEST was not performed, go to QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If QUICK TEST was performed, go to next step.
- DTC P0320: Erratic Ignition
Check for following:- Loose wires/connectors.
- Arcing secondary ignition components (coil, wires, plugs).
- 2-way radio.
Verify all 2-way radio installations regarding routing of antenna and power leads. Carefully follow manufacturer's installation instructions. If any of these faults are present, repair as necessary. After repair, go to step 25. If these possible causes are not present and condition is intermittent, refer to INTERMITTENT testing under SYSTEM TESTS . If condition is not intermittent, go to next step.
- Check CKP(+)/CKP(-) Continuity
Disconnect CKP sensor harness connector and PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance of CKP(+) circuit between breakout box terminal No. 21 and CKP sensor harness connector (Black/Pink wire). See Fig 1. Measure resistance of CKP(-) circuit between breakout box terminal No. 22 and CKP sensor harness connector (Gray/Yellow wire). If each resistance reading is more than 5 ohms, repair open circuit. See WIRING DIAGRAMS article. If resistance reading is not as specified, go to next step. - Check For CKP(+) Bias Voltage Fault
Remove breakout box. Reconnect PCM 104-pin harness connector. Turn ignition on, engine off. Measure voltage between CKP(+) terminal (Black/Pink wire) at CKP harness connector and negative battery terminal. Turn ignition off. If voltage reading is 1.0-2.0 volts, go to next step. If voltage reading is not as specified, go to step 17. - Check For CKP(-) Bias Voltage Fault
Turn ignition on, engine off. Measure voltage between CKP(-) terminal (Gray/Yellow wire) at CKP sensor harness connector and negative battery terminal. Turn ignition off. If voltage reading is 1.0-2.0 volts, go to step 9. If voltage reading is not as specified, go to next step. - Determine If Bias High Or Bias Low Fault
If bias voltage reading for CKP(-) circuit is less than one volt (bias low fault), go to next step. If bias voltage reading is more than 2.0 volts (bias high), go to step 8. - Check For CKP(-) Short To Ground In Harness
Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance of CKP(-) circuit between breakout box terminal No. 22 and negative battery terminal. If resistance reading is more than 10,000 ohms, replace PCM. After repair, go to step 25. If resistance reading is not as specified, repair short in Gray/Yellow wire between PCM 104-pin harness connector and CKP sensor harness connector. See WIRING DIAGRAMS article. After repair, go to step 25. - Check For CKP(-) Short To Power In Harness
Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Turn ignition on, engine off. Measure voltage of CKP(-) circuit between breakout box terminal No. 22 and negative battery terminal. If voltage reading is less than 0.5 volt, replace PCM. After repair, go to step 25. If voltage reading is not less than 0.5 volt repair short to power in Gray/Yellow wire between PCM 104-pin harness connector terminal No. 22 and CKP sensor harness connector. See WIRING DIAGRAMS article. After repair, go to step 25. - Check CKP Sensor Amplitude At PCM
Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure voltage between breakout box terminal No. 21 (CKP+) and terminal No. 22 (CKP-) while cranking engine. If settled AC voltage reading was more than 0.4 volt, go to next step. If settled AC voltage reading was not as specified, go to step 11. - Check CKP(+) Circuit For Short To Ground At Sensor
Measure resistance of CKP(+) circuit between breakout box terminal No. 21 and negative battery terminal. If resistance reading is more than 10,000 ohms, go to step 20. If resistance reading is not as specified, go to step 15. - Check CKP Circuit Resistance For Amplitude Fault
Measure resistance between breakout box terminal No. 21 (CKP+) and terminal No. 22 (CKP-). If resistance reading is 300-800 ohms, go to step 14. If resistance reading is not as specified, go to next step. - Determine If Resistance High Or Resistance Low Fault
If resistance reading between CKP(+) and CKP(-) was less than 300 ohms, go to next step. If resistance reading was not as specified, replace CKP sensor. After repair, go to step 25. - Check CKP(+) For Short To CKP(-)
Disconnect CKP sensor. Measure resistance between CKP(+) and CKP(-) at CKP sensor harness connector. If resistance reading is less than 5 ohms, repair short. See WIRING DIAGRAMS article. After repair, go to step 25. If resistance reading is not as specified, go to next step. - Check CKP Sensor & Pulse Wheel
Visually inspect pulse wheel and CKP sensor for damage. If CKP sensor and pulse wheel are okay, replace CKP sensor. If CKP sensor or pulse wheel are damaged, repair or replace damaged parts. After repair, go to step 25. - Check For Open Or Short In PCM
Disconnect CKP sensor harness connector. Remove Breakout Box. Reconnect PCM 104-pin harness connector to PCM. Measure resistance between CKP(+) and CKP(-) at CKP harness connector. If resistance reading is 16,000-24,000 ohms, go to next step. If resistance reading is not as specified, replace PCM. After repair, go to step 25. - Check CKP(+) For Short To CKP(-)
Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance between CKP(+) and CKP(-) at CKP sensor harness connector. If resistance reading is more than 1000 ohms, replace CKP sensor. After repair, go to step 25. If resistance reading is less than 1000 ohms, repair short circuit. See WIRING DIAGRAMS article. After repair, go to step 25. - Determine If Bias Voltage High Or Bias Voltage Low Fault
If bias voltage was measured less than one volt, go to next step. If bias voltage was measured more than one volt, go to step 19. - Check CKP(+) Circuit For Short To Ground In Harness
Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Measure resistance between breakout box terminal No. 21 (CKP+) and negative battery terminal. If resistance reading is more than 10,000 ohms, replace PCM. After repair, go to step 25. If resistance reading is 10,000 ohms or less, repair short in Black/Pink wire between PCM 104-pin harness connector terminal No. 21 and CKP sensor harness connector. See WIRING DIAGRAMS article. After repair, go to step 25. - Check CKP(+) Circuit For Short To Power In Harness
Disconnect PCM 104-pin harness connector. Connect Breakout Box (49-UN01-130) to PCM harness connector only. See Figure. Turn ignition on, engine off. Measure voltage between breakout box terminal No. 21 (CKP+) and negative battery terminal. If voltage reading is less than 0.5 volts, replace PCM. After repair, go to step 25. If voltage reading is more than 5.0 volts, repair short to power on Pink/Black wire between PCM 104-pin harness connector terminal No. 21 and CKP sensor harness connector. See WIRING DIAGRAMS article. After repair, go to step 25. - Visual Inspection Of Ignition System
Visually inspect engine compartment to make sure all coils and spark plug wires are secured properly. Examine all wiring harnesses and connectors for damaged, burned or overheated insulation and loose or broken connections. Ensure battery is fully charged. Verify all accessories are off. If no problem is indicated, go to next step. If a problem is indicated, repair as necessary. After repair, go to step 25. - DTC P0301 - P0306: Misfire On Specific Cylinder
Are DTCS P0301-P0306 present, go to DTC P0300, P0301, P0302, P0303, P0304, P0305 OR P0306 . If DTCs P0301-P0306 are not present, go to next step. - Check For Spark At All Cylinders
Disable inertia fuel shutoff switch. Check for spark at each cylinder while cranking engine. If bluish white spark is consistent between all cylinders, turn ignition off. Go to next step. If bluish white spark is not consistent between all cylinders, turn ignition off. Inspect plug wires (2.0L). Measure resistance of spark plug wires and replace them if more than 7000 ohms per foot. After repair, go to step 25. - Check Spark Plugs
Remove and inspect plugs for damage, wear, carbon deposits and proper plug gap. If plugs are okay, go to next step. If spark plugs are not okay, clean spark plugs or regap. Replace if necessary. After repair, go to step 25. - Check Spark Plug Resistance
Measure spark plug resistance. If resistance reading is 2000-20,000 ohms, fault is intermittent. Refer to INTERMITTENT testing under SYSTEM TESTS . If resistance reading is not as specified, go to next step. - Verify Trouble Shooting Of DTCs Completed
Perform QUICK TEST under SELF-DIAGNOSTIC SYSTEM. If any DTC is present, go to applicable procedure for other DTCs. See DIAGNOSTIC TROUBLE CODE DEFINITIONS . If no DTCs are set, trouble shooting is complete.