Diagnostic Test
- PCM WIRING OR CONNECTORS
- Turn the ignition off.
- Using the wiring diagram/schematic as a guide, inspect the wiring and each connector at the PCM.
- Look for any chafed, pierced, pinched, or partially broken wires.
- Look for broken, bent, pushed out or corroded terminals.
Were any problems found?
Yes
- Repair as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, Refer to POWERTRAIN VERIFICATION TEST . For 5.7L, Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 2
- CHECKING THE PCM GROUND CIRCUITS
- Turn the ignition off.
- Using a 12 volt test light connected to 12 volts, check the PCM ground circuits.
- Wiggle test each circuit during the test to check for an intermittent open in the circuit.NOTE:
The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
- Go To 3.
No
- Repair the PCM ground circuit(s) for an open circuit or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, Refer to POWERTRAIN VERIFICATION TEST . For 5.7L, Refer to POWERTRAIN VERIFICATION TEST .
- CHECKING THE PCM FUSED IGNITION CIRCUITS
- Turn the ignition on.
- Using a 12 volt test light connected to ground, check the PCM Fused Ignition circuits.
- Check each circuit with the ignition on, engine running position, and during cranking.
- Wiggle test each circuit during the test to check for an intermittent open in the circuit.NOTE:
The test light should be illuminated and bright. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated and bright?
Yes
- Go To 4.
No
- Repair the open or short to ground in the PCM Fused Ignition circuits.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, Refer to POWERTRAIN VERIFICATION TEST . For 5.7L, Refer to POWERTRAIN VERIFICATION TEST .
- CHECK THE IGNITION OFF/RUN/START CONTROL OUTPUT CIRCUIT
- Using a 12-volt test light connected to ground, check the Ignition Off/Run/Start Control Output Circuit.
- Check each circuit with the ignition on, engine running position, and during cranking.
- Wiggle test each circuit during the test to check for an intermittent open in the circuit.NOTE:
The test light should be illuminated and bright with the ignition on and not illuminated with the ignition off. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated as described above?
Yes
- Go To 5
No
- Repair the open or short to ground in the Ignition Off/Run/Start Control Output Circuit.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, Refer to POWERTRAIN VERIFICATION TEST . For 5.7L, Refer to POWERTRAIN VERIFICATION TEST .
- CHECKING THE PCM FUSED B+ CIRCUITS
- Turn the ignition off.
- Using a 12 volt test light connected to Ground, check the PCM Fused B+ circuits.
- Wiggle test each circuit during the test to check for an intermittent open in the circuit.NOTE:
The test light should be illuminated and bright with the ignition on and not illuminated with the ignition off. Compare the brightness to that of a direct connection to the battery.
Is the test light illuminated as described above?
Yes
- Test complete.
No
- Repair the open or short to ground in the PCM Fused B+ circuit(s) as necessary.
- Perform the POWERTRAIN VERIFICATION TEST. For 3.6L, Refer to POWERTRAIN VERIFICATION TEST . For 5.7L, Refer to POWERTRAIN VERIFICATION TEST .