Operation CHARM: Car repair manuals for everyone.

Precautions in Diagnosing Trouble




Precautions in Diagnosing Trouble

- Do not disconnect connectors from TCM, battery cable from battery, TCM ground wire harness from engine or main fuse before checking the diagnosis information (pending DTC, confirmed DTC, freeze frame data, etc.) other than permanent DTC stored in TCM memory.
Such disconnection will clear memorized information in TCM memory.
- Diagnostic information stored in TCM memory can be cleared as well as checked by using SUZUKI scan tool or CAN communication OBD generic scan tool.
However, for the permanent DTC, it can not be cleared by using SUZUKI scan tool or CAN communication OBD generic scan tool. (For details for permanent DTC, refer to On-Board Diagnostic System Description On-Board Diagnostic System Description.)
Before using scan tool, read its "Operator's (Instruction) Manual" carefully to have good understanding as to what functions are available and how to use it.
It is indistinguishable which module turns on MIL because not only ECM but also TCM turns on MIL. (For details for permanent DTC, refer to On-Board Diagnostic System Description On-Board Diagnostic System Description.)
Therefore, check both ECM and TCM for DTC when MIL lights on.
- When checking TCM for DTC, keep in mind that DTC is displayed on the scan tool as follows depending on the scan tool used.

- SUZUKI scan tool displays DTC detected by TCM.
- CAN communication OBD generic scan tool displays DTC detected by both ECM and TCM simultaneously.

- When performing the following services, all learned controls which are stored in TCM memory should be initialized after the replacement. Programming and Relearning
Neglecting this initialization may cause excessive shift shock.

- TCM replacement
- CVT assembly replacement

- Be sure to read Precautions for Electrical Circuit Service Precautions for Electrical Circuit Service
before inspection and observe what is written there.
- TCM replacement

- When substituting a known-good TCM, check that all relays and actuators have resistance of specified value.
Neglecting this check may result in damage to good TCM.

- Communication of ECM, BCM, combination meter, keyless start control module (keyless start model), ABS / ESP(R) control module, 4WD control module (4WD model), steering angle sensor (ESP(R) model), Yaw rate / G sensor (ESP(R) model), SDM (advanced air bag model), ID controller (Canada model), TCM and DLC, is established by CAN (Controller Area Network). For more detail of CAN communication system, refer to Description and Operation CAN Communication System Description. Also, be sure to handle CAN communication line with care. Precaution for CAN Communication System