Diagnostic System Check - Rear Axle - Locking/Limited Slip

Diagnostic System Check - Locking/Limited Slip Rear Axle

Circuit Description
The Diagnostic System Check is an organized approach to identify a condition created by the rear axle controls. The Diagnostic System Check is the starting point for a rear axle controls complaint. The Diagnostic System Check directs you to the next logical step for diagnosing a rear axle control concern. Perform this check only if there is a driveability complaint or if you have been directed here from another service information section.

Follow the table to help reduce diagnostic time and help prevent unnecessary replacement of parts.

Diagnostic Aids

Important:
^ Do not clear the DTC unless directed by a diagnostic procedure. Clearing the DTCs will erase all Freeze Frame and Failure Records stored in PCM memory.
^ Poor engine performance can sometimes be diagnosed as a rear axle driveability condition. In order to avoid mix-diagnosis of the rear axle, always perform Diagnostic System Check - Engine Controls.
^ Use a scan tool that is known to function correctly. If necessary, test the scan tool on another vehicle.
^ Ensure the scan tool contains the most current file available.
^ The scan tool will display a loss of communication error message under the following conditions:
- The PCM power is interrupted.
- The ignition switch is turned OFF.
- The battery voltage level is very low.
- A poor connection at the diagnostic link connector (DLC).

Test Description
The numbers below refer to the step numbers on the diagnostic table.
1. This step determines if the scan tool is receiving power through the DLC connector.
2. This step determines if the PCM is transmitting class 2 serial data to the DLC and that the Class 2 data circuit is not open or shorted.
3. This step determines if an antilock brake system (ABS) DTC has disabled the All Wheel Drive (AWD) system.

Steps 1 - 3:

Steps 4 - 5:

Diagnostic System Check - Locking/Limited Slip Rear Axle