Diagnostic Test

WARNING: This page is about a different car, the 2012 Jeep Liberty. However, it is still accessible from the selected car via links, so may be relevant.

ENGINE DTCS PRESENT
1. With the scan tool, read Engine DTCs.
  Are there any Engine brake DTCs present?
  
  Yes
  - Refer to DIAGNOSTIC CODE INDEX and perform the appropriate diagnostic procedure.
  - Refer to STANDARD PROCEDURE and perform the NAG1 TRANSMISSION VERIFICATION TEST.
  No
  - Go To 2.
ABS MODULE DTCS PRESENT
1. With the scan tool, read ABS Module DTCs.
  Are there any ABS DTCs present?
  
  Yes
  - Refer to DIAGNOSTIC CODE INDEX and perform the appropriate diagnostic procedure.
  - Refer to STANDARD PROCEDURE and perform the NAG1 TRANSMISSION VERIFICATION TEST.
  No
  - Go To 3.
(L51) BRAKE SWITCH SIGNAL SHORT TO GROUND

Fig 1: Checking Brake Switch Signal For Short To Ground
Courtesy of CHRYSLER GROUP, LLC
1. Turn the ignition off to the lock position.
2. Disconnect the Shift Lever Assembly harness connector.
  NOTE:
  Check connectors - Clean/repair as necessary.
3. Measure the resistance between ground and the (L51) Brake Switch Signal circuit.
  Is the resistance below 5.0 ohms?
  
  Yes
  - Repair the (L51) Brake Switch Signal for a short to ground.
  - Refer to STANDARD PROCEDURE and perform the NAG1 TRANSMISSION VERIFICATION TEST.
  No
  - Using the schematics as a guide, inspect the wiring and connectors. Repair as necessary. Pay particular attention to all power and ground circuits. If no problems are found, replace the Shift Lever Assembly in accordance with the Service Information.
  - Refer to STANDARD PROCEDURE and perform the NAG1 TRANSMISSION VERIFICATION TEST.