Diagnostic Test

WARNING: This page is about a different car, the 2005 Jeep Grand Cherokee. However, it is still accessible from the selected car via links, so may be relevant.

1) CHECK FOR FCM CAN BUS DTCS
With the scan tool, read FCM DTCs.

Are there any FCM CAN BUS DTC's present?

Yes
1. Refer to ELECTRONIC CONTROL MODULES - ELECTRICAL DIAGNOSTICS category and perform the appropriate symptom.
No
1. Go To step 2).
2) ELECTRONIC SHIFT MODULE DTC'S PRESENT
With the scan tool, read Electronic Shift Module (ESM) DTCs.

Are there any ESM DTC's present?

Yes
1. Refer to SHIFTER DIAGNOSTICS - NAG1 and perform the appropriate diagnostic procedure.
2. Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1 .
No
1. Using the schematics as a guide, check the Transmission Control Module (TCM) pins, terminals, and connectors for corrosion, damage, or terminal push out. Pay particular attention to all power and ground circuits. If no problems are found, replace the TCM per the Service Information. Refer to ELECTRONIC CONTROL MODULES - SERVICE INFORMATION for the appropriate service procedure.
2. Perform NAG1 TRANSMISSION VERIFICATION TEST - VER 1 .