Trouble Code Descriptions

DIAGNOSTIC TROUBLE CODES

Diagnostic trouble codes (DTCs) are codes stored by the Transmission Control Module (TCM) and the Shift Lever Assembly Module (SLA) to help diagnose Transmission and Shifter problems. They are viewed using the DRBIII scan tool.

Always begin by performing a visual inspection of the wiring, connectors, cooler lines and the transmission. Any obvious wiring problems or leaks should be repaired prior to performing any diagnostic test procedures. Some engine driveability problems can be misinterpreted as a transmission problem. Ensure that the engine is running properly and that no ECM DTCs are present that could cause a transmission complaint.

If there is a communication K-ABS,Shifter or K-TCM circuit problem, trouble codes will not be accessible until the problem is fixed. The DRBIII will display an appropriate message. The following is a possible list of causes for a bus problem:
- open or short to ground/battery in K line circuit.
- internal failure of any module or component connected to the K line circuit

Each diagnostic trouble code is diagnosed by following a specific testing sequence. The diagnostic test procedures contain step-by-step instructions for determining the cause of a transmission diagnostic trouble code. Possible sources of the code are checked and eliminated one by one. It is not necessary to perform all of the tests to diagnose an individual code. These tests are based on the problem being present at the time that the test is run.

If the TCM records a DTC that will adversely affect the vehicles transmission, it will request (via the communication bus) that the ECM illuminate the Malfunction Indicator Lamp (MIL). All transmission DTCs will be stored in the TCM.