Diagnostic Test

WARNING: This page is about a different car, the 2024 Jeep Grand Wagoneer L and 2024 Jeep Grand Wagoneer. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR ANY SERVICE BULLETINS OR PCM SOFTWARE UPDATES
1. Check for any applicable Service Bulletins or Flash updates related to the DTC.
  Are there any applicable Service Bulletins or Flash updates?
  
  Yes
  - Perform the applicable repair.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 2
READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
3. With the scan tool, erase all DTCs.
4. Turn the ignition off for a minimum of 10.0 seconds.
5. Turn the ignition on.
6. Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
7. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
INSPECT THE AUXILIARY COOLANT PUMP FOR SIGNS OF PHYSICAL DAMAGE
1. Inspect the Auxiliary Coolant Pump and connector for damage due to road debris.
  Is the Charge Air Cooler Coolant Pump or connector damaged or disconnected?
  
  Yes
  - Repair as necessary.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To 4
CHECK THE (A501) FUSED B+ CIRCUIT VOLTAGE
1. Turn the ignition off.
2. Disconnect the Auxiliary Coolant Pump harness connector.
3. Turn the ignition on.
4. Measure the voltage on the (A501) Fused B+ circuit at the Auxiliary Coolant Pump harness connector.
  Is the voltage equal to battery voltage?
  
  Yes
  - Go To the appropriate Service Information
  No
  - Repair the (A501) Fused B+ circuit for an open or short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE AUXILIARY PUMP (Z921) GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Turn the ignition off.
2. Measure the resistance between ground and the (Z921) Ground circuit at the Charge Air Cooler Coolant Pump harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To the appropriate Service Information
  No
  - Repair the (Z921) Ground circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK THE (D505) LIN BUS CIRCUITS FOR A SHORT TO GROUND
1. Disconnect the PCM C1 harness connector.
2. Check for continuity between ground and the (D505) LIN BUS circuit at the Charge Air Cooler Coolant Pump harness connector.
  Is there continuity between ground and the (D505) LIN BUS circuit?
  
  Yes
  - Repair the (D505) LIN BUS circuit for a short to ground.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - Go To the appropriate Service Information
CHECK THE (D505) LIN BUS CIRCUIT FOR AN OPEN/HIGH RESISTANCE
1. Measure the resistance of the (D505) LIN BUS circuit between the Charge Air Cooler Coolant Pump harness connector and the PCM C1 harness connector.
  Is the resistance below 3.0 Ohms?
  
  Yes
  - Go To the appropriate Service Information
  No
  - Repair the (D505) LIN BUS circuit for an open or high resistance.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHARGE AIR COOLER COOLANT PUMP
1. Replace the Charge Air Cooler Coolant Pump in accordance with the Service Information.
2. Reconnect the PCM C1 harness connector.
3. Turn the ignition on.
4. With the scan tool, erase DTCs.
5. Cycle the ignition off, then back on
6. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To the appropriate Service Information
  No
  - Replacing the Charge Air Cooler Coolant Pump repaired the fault.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all PCM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
4. Inspect harness connectors, component connectors, and all male and female terminals for the following conditions:
  - Proper connector installation.
  - Damaged connector locks.
  - Corrosion.
  - Other signs of water intrusion.
  - Weather seal damage (if equipped).
  - Bent terminals.
  - Overheating due to a poor connection (terminal may be discolored due to excessive current draw).
  - Terminals that have been pushed back into the connector cavity.
  - Check for spread terminals and verify proper terminal tension.
  Repair any conditions that are found.
5. Connect all PCM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
6. Connect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. Connect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. With the scan tool, erase DTCs.
9. Test drive or operate the vehicle in accordance with the when monitored and set conditions.
10. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Replace and program the Powertrain Control Module (PCM) in accordance with the Service Information. Refer to MODULE, POWERTRAIN CONTROL (PCM), REMOVAL AND INSTALLATION .
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
  No
  - The wiring or poor connection problem has been repaired.
  - Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .