Diagnostic Test

PCM GROUND CIRCUIT(S) OPEN
1. Turn the ignition off.
2. Disconnect the PCM C1 harness connector.
3. Using a 12-volt test light connected to 12 volts, probe each of the PCM ground circuits at the PCM C1 harness connector, cavities 2, 4 and 6.
  Did the test light illuminate for each cavity?
  
  Yes
  - Go To 2
  No
  - Repair the PCM Ground circuit(s) for an open.
  - Perform the PCM VERIFICATION TEST - 3.0L DIESEL - 2.0L DIESEL. Refer to 3.0L DIESEL - INTERMITTENT CONDITION, PCM VERIFICATION TEST AND PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
(F942) FUSED IGNITION SWITCH OUTPUT (START/RUN) CIRCUIT OPEN
1. Turn the ignition to the Run position.
2. Using a 12-volt test light connected to ground, check the Fused Ignition Switch Start/Run Output circuit at the PCM C1 harness connector, cavity 54.
3. Turn the ignition to the Start position.
4. Using a 12-volt test light connected to ground, check the Fused Ignition Switch Start/Run Output circuit at the PCM C1 harness connector, cavity 54.
  Is the test light on for both ignition switch positions?
  
  Yes
  - Go To 3
  No
  - Repair the Fused Ignition Switch Start/Run Output circuit for an open.
  - Perform the PCM VERIFICATION TEST - 3.0L DIESEL - 2.0L DIESEL. Refer to 3.0L DIESEL - INTERMITTENT CONDITION, PCM VERIFICATION TEST AND PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
CHECKING THE MAIN RELAY SYSTEM
1. Turn the ignition off.
2. Connect a jumper wire between ground and the (K51) ASD Relay Control circuit at the PCM C1 harness connector, cavity 29.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check the Fused ASD Relay Output circuits at the PCM C1 harness connector, cavities 1, 3 and 5.
  Does the test light illuminate brightly for each circuit?
  
  Yes
  - Test Complete.
  No
  - Go To 4
FUSED ASD RELAY BATTERY SUPPLY CIRCUIT OPEN
1. Turn the ignition off.
2. Remove the ASD Relay.
3. Turn the ignition on.
4. Using a 12-volt test light connected to ground, check both Fused ASD Relay Battery Supply circuits (terminal 30) at both ASD Relay connectors.
  Is the test light illuminated and bright?
  
  Yes
  - Go To 5
  No
  - Repair the Fused Main Relay Battery Supply circuit(s) for an open.
  - Perform the PCM VERIFICATION TEST - 3.0L DIESEL - 2.0L DIESEL. Refer to 3.0L DIESEL - INTERMITTENT CONDITION, PCM VERIFICATION TEST AND PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
ASD RELAY OUTPUT CIRCUITS OPEN
1. Connect a jumper wire between cavity 30 and cavity 87 at the ASD Relay connector.
2. Using a 12-volt test light connected to ground, check the ASD Relay Output circuit in PCM C1 harness connector, cavities 1, 3 and 5.
  Did the test light illuminate for each circuit?
  
  Yes
  - Go To 6
  No
  - Repair the Main Relay Output circuit(s) for an open.
  - Perform the PCM VERIFICATION TEST - 3.0L DIESEL - 2.0L DIESEL. Refer to 3.0L DIESEL - INTERMITTENT CONDITION, PCM VERIFICATION TEST AND PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
ASD RELAY
1. Turn the ignition off.
2. Install a known good relay in place of the ASD Relay.
3. Connect a jumper wire between ground and the ASD Relay Control circuit in PCM C1 harness connector cavity 28.
4. Turn the ignition on.
5. Using a 12-volt test light connected to ground, check the Fused ASD Relay Output circuits at the PCM C1 harness connector, cavities 1, 3 and 5.
  Did the test light illuminate brightly for each circuit?
  
  Yes
  - Replace the ASD Relay.
  - Perform the PCM VERIFICATION TEST - 3.0L DIESEL - 2.0L DIESEL. Refer to 3.0L DIESEL - INTERMITTENT CONDITION, PCM VERIFICATION TEST AND PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .
  No
  - Repair the ASD Relay Control circuit for an open.
  - Perform the PCM VERIFICATION TEST - 3.0L DIESEL - 2.0L DIESEL. Refer to 3.0L DIESEL - INTERMITTENT CONDITION, PCM VERIFICATION TEST AND PRE-DIAGNOSTIC TROUBLESHOOTING PROCEDURE .