Diagnostic Strategies

INTRODUCTION
The procedures provided include all of the specifications, instructions, and graphics needed to diagnose the 1997 AW4 transmission. The diagnostics in this manual are based on the failure condition or symptom being present at the time of diagnosis.

When repairs are required, refer to the procedure for the proper removal and repair procedure.

Diagnostic procedures change every year. New diagnostic systems may be added: carryover systems may be enhanced. It is recommended that you review the entire section to become familiar with all new and changed diagnostic procedures.

The AW4 transmission control system has been improved significantly this model year. Many new codes have been added. The Park/Neutral switch has been replaced by a Transmission Range Sensor (TRS). The Transmission Control Module (TCM) now has the ability to communicate with the Powertrain Control Module (PCM) via the Chrysler Collision Detection (CCD) Bus. The TCM also has the ability to monitor transmission faults which could affect emissions. Any transmission fault which will adversely affect emissions will set a DTC in the PCM and will also illuminate the Malfunction Indicator Lamp (MIL).

System Coverage
This diagnostic information covers all 1997 Jeep Cherokees (XJ) equipped with an AW4 Electronic Transmission.

Six-Step Troubleshooting Procedure
Diagnosis of the AW4 electronic transmission is done in six basic steps:
- verification of complaint
- verification of any related symptoms
- symptom analysis
- problem isolation
- repair of isolated problem
- verification of proper operation