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.
- READ AND RECORD DTCS AND ENVIRONMENTAL DATA - ERASE DTCS AND CHECK FOR THE DTC TO RETURN
- With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
- For future reference, with the scan tool, run and save a vehicle Scan Report and all related recorded data.
- With the scan tool, erase all DTCs.
- Turn the ignition off for a minimum of 10.0 seconds.
- Turn the ignition on.
- Using the When Monitored and Set Conditions above and recorded data, operate the vehicle in the conditions that set the DTC.
- With the scan tool, read DTCs.
Did the DTC return?
No
- Go To 2
Yes
- Go To 3
- CHECK FOR OTHER DTCS
- Refer to the recorded DTCs.
Are there any low voltage DTCs stored?
Yes
- This DTC can set if a low voltage condition is present.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Perform the INTERMITTENT CONDITION diagnostic procedure. Refer to INTERMITTENT CONDITION .
- Refer to the recorded DTCs.
- CHECK THE COOLING SYSTEM OPERATION NOTE:
This is an after-run coolant pump. This pump cannot cause an overheating condition. Diagnose an overheating condition before continuing with this diagnostic test.
- Check the vehicle history for an overheating condition.
- Start the vehicle and allow the engine to operating temperature.
Is there an overheating condition?
Yes
- Repair the overheating condition.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 4
- ISOLATE AND CHECK THE COOLANT PUMP (A501) SUPPLY CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- The ignition must be off when checking the continuity of a circuit.
- Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the component harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note: The meter leads can add resistance to the measurement value.
- Connect one lead of the DVOM to the circuit being tested at the component harness connector.
- Connect the other lead to the circuit being tested at the PCM connector and measure the resistance of the circuit.
Is the resistance below 3.0 Ohms?
Yes
- Go To 5
No
- Repair the circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- ISOLATE AND CHECK THE COOLANT PUMP (A501) SUPPLY CIRCUIT FOR A SHORT TO ANOTHER CIRCUIT AT THE PCM HARNESS CONNECTOR
- The ignition must be off when performing a resistance check to find a short between circuits.
- Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. At this time leave all in-line connectors connected. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Connect one lead of the DVOM to the circuit being tested at the ECU harness connector.
- With the other lead of the DVOM probe all other circuits at the ECU harness connector.NOTE:
With the circuit isolated there should be no continuity between the circuit being tested and any other circuit.
Is there continuity between the circuit being tested and any other circuit?
Yes
- Repair the short between the circuits that have continuity. Use the wiring diagram as a guide to trace the circuits and look for any in-line connectors to help isolate the location of the short.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To the appropriate Service Information
- ISOLATE AND CHECK THE COOLANT PUMP (A501) SUPPLY CIRCUIT FOR A SHORT TO GROUND
- The ignition must be off when checking a circuit for continuity to ground.
- Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and every component harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Connect the negative lead of the DVOM to a known good ground.
- With the positive lead of the DVOM, probe the circuit being tested at the component harness connector and check for continuity between the circuit and ground.NOTE:
There should be no continuity between ground and the circuit being tested.
Is there continuity between ground and the circuit being tested?
Yes
- Repair the circuit for a short to ground. Use the wiring diagram as a guide to trace the circuit and look for any in-line connectors to help isolate the location of the short.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Go To 7
- ISOLATE AND CHECK THE (Z905) GROUND CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- The ignition must be off when checking the continuity of a circuit.
- Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the component harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note: The meter leads can add resistance to the measurement value.
- Connect one lead of the DVOM to the circuit being tested at the component harness connector.
- Connect the other lead to the circuit being tested at the PCM connector and measure the resistance of the circuit.
Is the resistance below 3.0 Ohms?
Yes
- Go To the appropriate Service Information
No Refer to 8 .
- Repair the circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
- ISOLATE AND CHECK THE (D505) LIN BUS CIRCUIT FOR AN OPEN/HIGH RESISTANCE
- The ignition must be off when checking the continuity of a circuit.
- Isolate the circuit by disconnecting the Electronic Control Unit (ECU) and the component harness connector containing the circuit being tested. Note: Use the wiring diagram as a guide to follow the path of the circuit.
- Before measuring the resistance of any circuit, first measure the resistance between the two leads of the DVOM. Note: The meter leads can add resistance to the measurement value.
- Connect one lead of the DVOM to the circuit being tested at the component harness connector.
- Connect the other lead to the circuit being tested at the PCM connector and measure the resistance of the circuit.
Is the resistance below 3.0 Ohms?
Yes
- Replace the High Temperature Coolant Pump in accordance with the service information.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .
No
- Repair the circuit for an open or high resistance.
- Perform the POWERTRAIN VERIFICATION TEST. Refer to POWERTRAIN VERIFICATION TEST .