Diagnostic Test

WARNING: This page is about a different car, the 2017 Jeep 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
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 seconds.
5. Start the engine and allow it to idle for at least 2 minutes.
6. With the scan tool, read DTCs.
  Did the DTC return?
  
  Yes
  - Go To 2
  No
  - Perform the TESTING FOR AN INTERMITTENT CONDITION. Refer to TESTING FOR AN INTERMITTENT CONDITION .
REPLACE THE FORWARD COLLISION WARNING SWITCH - ERASE DTCS AND CHECK FOR DTC TO RETURN
1. Turn the ignition off.
2. Replace the Forward Collision Warning Switch in accordance with the Service Information.
3. With the scan tool, erase ACC DTCs.
4. Turn the ignition off for a minimum of 10 seconds.
5. Start the engine and allow it to idle for at least 2 minutes.
6. With the scan tool, read ACC DTCs.
  Did the DTC return?
  
  Yes
  - Go To 3
  No
  - Replacing the Forward Collision Warning Switch corrected the condition.
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
CHECK RELATED HARNESS CONNECTIONS
1. Turn the ignition off.
2. Disconnect all ACC harness connectors.
3. Disconnect all related in-line harness connections (if equipped).
4. Disconnect the related component harness connectors.
5. 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.
6. Reconnect all ACC harness connectors. Be certain that all harness connectors are fully seated and the connector locks are fully engaged.
7. Reconnect all in-line harness connectors (if equipped). Be certain that all connectors are fully seated and the connector locks are fully engaged.
8. Reconnect all related component harness connectors. Be certain that all connectors are fully seated and the connector locks are fully engaged.
9. With the scan tool, erase DTCs.
10. Turn the ignition off for a minimum of 10 seconds.
11. Start the engine and allow it to idle for at least 2 minutes.
12. With the scan tool, read ACC DTCs.
  Did the DTC return?
  
  Yes
  - Replace the Adaptive Cruise Control (ACC) Module in accordance with the Service Information. Refer to MODULE, ADAPTIVE CRUISE CONTROL (ACCM), REMOVAL .
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .
  No
  - Repairing the wiring or the connectors corrected the condition.
  - Perform the ADAPTIVE CRUISE CONTROL VERIFICATION TEST. Refer to STANDARD PROCEDURE .