Diagnostic Test

WARNING: This page is about a different car, the 2021 Jeep Grand Cherokee L. 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
1. With the scan tool, read DTCs in all Electronic Control Units (ECUs) and record on the repair order.
2. With the scan tool, run a Vehicle Scan Report, or record the Environmental Data related to the DTCs.
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 recorded Environmental Data and the When Monitored Conditions above, 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 .
VERIFY ENGINE COOLANT TEMPERATURE READING
1. With the scan tool, read engine coolant temperature in the Powertrain Control Module (PCM).
  Is the engine coolant temperature reading 70° C (160° F) or above?
  
  Yes
  - Allow engine coolant temperature measurement to decrease below (98.6° F) and retest. Refer to 1.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Go To 3
CHECK FOR DTCS IN THE RADIO
1. Refer to the saved DTC information recorded on the repair order.
  Were any DTCs set in the Radio?
  
  Yes
  - Repair the Radio DTC(s) and retest. Refer to DIAGNOSTIC CODE INDEX .
  No
  - Go To 4
CHECK RELATED HARNESS CONNECTIONS
1. Disconnect all DSM harness connectors.
2. Disconnect all related in-line harness connections (if equipped).
3. Disconnect the related component harness connectors.
  NOTE:
  Inspect area behind the DSM. Make sure no aftermarket devices are installed within the area behind the DSM, that all HVAC housing ducts are correctly installed, and that the ducts aren't leaking cabin air near the DSM.
  
  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.
  - Perform a terminal drag test on each connector terminal to verify proper terminal tension.
  Repair any conditions that are found.
4. Reconnect all DSM harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
5. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
6. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
7. With the scan tool, erase DTCs.
8. Using the recorded Environmental Data, along with the When Monitored and Set Conditions above, operate the vehicle in the conditions that set the DTC.
9. With the scan tool, read DSM DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Display Screen Module (DSM) in accordance with the Service Information. Refer to MODULE, DISPLAY SCREEN (DSM), REMOVAL AND INSTALLATION .
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .
  No
  - Test complete.
  - Perform the BODY VERIFICATION TEST. Refer to BODY VERIFICATION TEST .