Introduction

The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM (transmission control module) in combination with the ECM. The malfunction is indicated by the MIL (malfunction indicator lamp) and is stored as a DTC in the ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicated by the O/D OFF indicator lamp. The malfunction is stored in the TCM memory. The detected items are overlapped with OBD-II self-diagnostic items.
- A/T self-diagnosis is performed by the TCM in combination with the ECM. The results can be read through the blinking pattern of the OBD OFF indicator or the malfunction indicator lamp (MIL).
- The self-diagnostic results indicated by the MIL are automatically stored in both the ECM and TCM memories.
Always erase the DTC when repairs are completed to avoid unnecessary blinking of the MIL.
- The following self-diagnostic items can be detected using ECM self-diagnostic results mode* only when the O/D OFF indicator lamp does not indicate any malfunctions.
- Inhibitor switch
- A/T 1st, 2nd, 3rd, or 4th gear function
- A/T TCC S/V function (lock-up).