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.

VERIFY THE DIAGNOSTIC TROUBLE CODE (DTC) IS ACTIVE

NOTE:

Make sure the battery is fully charged before proceeding.

Turn the ignition on.
Using the scan tool, read the active DTCs.
Does the scan tool display: U0100-00-LOST COMMUNICATION WITH ECM/PCM?

Yes
- Refer to U0100-87-LOST COMMUNICATION WITH ECM/PCM - MISSING MESSAGE and perform the U0100-87-Lost Communication with ECM/PCM diagnostic procedure.
No
- Refer to STORED LOST COMMUNICATION DTCS and perform the Stored Lost Communication DTCs diagnostic procedure.