Diagnostic Test

WARNING: This page is about a different car, the 2025 Jeep Grand Cherokee. 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 DTC TO RETURN
WARNING:
On vehicles equipped with the high voltage system, you must thoroughly read and follow all High Voltage Safety procedures. In addition, before performing any diagnostic or service procedure near a high voltage component, you must perform the High Voltage Power Down. Failure to follow these instructions may result in possible serious or fatal injury.

Read the HIGH-VOLTAGE SAFETY PROCEDURES. Refer to HIGH VOLTAGE SAFETY PROCEDURES .

When the HIGH-VOLTAGE POWER-DOWN PROCEDURE is necessary. Refer to HIGH VOLTAGE POWER DOWN .
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 appropriate INTERMITTENT CONDITION diagnostic procedure. Refer to TESTING FOR AN INTERMITTENT CONDITION .
CHECK THE LOW TEMPERATURE COOLING LOOP FOR FAILURES
1. Check the Low Temperature Cooling Loop for proper operation. Also check for any cooling system DTCs especially P0480-00 and P0C4A-00.
2. Check the Low Temperature Cooling System for any leaks, proper fill level, and correct mixture of coolant.
3. Check the Cooling Fans for proper operation.
4. Check the Low Temperature Coolant Pumps for proper operation and flow.
  Were any problems found?
  
  Yes
  - Repair the Cooling System in accordance with the Service Information.
  - Perform the Hybrid Control Processor (HCP) VERIFICATION TEST. Refer to HYBRID CONTROL PROCESSOR (HCP) VERIFICATION TEST .
  No
  - Go To 3
CHECK TRANSMISSION FOR FAILURES
1. Refer to the recorded scan report, repair Transmission DTCs first and recheck operation.
2. Check the Transmission for proper fluid level and leaks, repair as necessary.
3. Check the Transmission Oil Cooler and Oil Cooler lines for obstructions and proper flow.
4. Check the Transmission Electric Oil Pump operation.
  Were any problems found?
  
  Yes
  - Repair the Transmission problem and recheck operation.
  - Perform the Hybrid Control Processor (HCP) VERIFICATION TEST. Refer to HYBRID CONTROL PROCESSOR (HCP) VERIFICATION TEST .
  No
  - Replace the Transmission in accordance with the Service information. Refer to 8P75PH AUTOMATIC TRANSMISSION, REMOVAL AND INSTALLATION .
  - If the DTC is still present after replacing the Transmission, replace the Power Inverter Module (PIM) in accordance with the Service information. Refer to MODULES, HIGH VOLTAGE SYSTEM, REMOVAL AND INSTALLATION .
  - Perform the Hybrid Control Processor (HCP) VERIFICATION TEST. Refer to HYBRID CONTROL PROCESSOR (HCP) VERIFICATION TEST .