Precautions For Diagnosing Trouble

Precautions in Diagnosing Trouble

- Don't disconnect ECM connectors from ECM, battery cable from battery, ECM ground wire harness from engine or main fuse before confirming diagnostic information (DTC, freeze frame data, etc.) stored in ECM memory. Such disconnection will erase memorized information in ECM memory.
- Diagnostic information stored in ECM memory can be cleared as well as checked by using SUZUKI scan tool or CAN communication OBD generic scan tool. 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 unable to distinguish which module, ECM or TCM, turns on MIL. (For details of on-board diagnostic system for A/T model, refer to On-Board Diagnostic System Description:5 A/T). On-Board Diagnostic (OBD) System Description Therefore, check both ECM and TCM for DTC when MIL turns on.
- When checking ECM for DTC, keep in mind that DTC is displayed on the scan tool as follows depending on the scan tool.
- SUZUKI scan tool displays DTC detected by ECM.
- CAN communication OBD generic scan tool displays DTC detected by both ECM and TCM simultaneously.

- Priorities for diagnosing troubles If two or more DTCs are stored, proceed to the flow of the DTC which has detected earliest in the order and follow the instruction in that table. If no instructions are given, troubleshoot DTCs according to the following priorities.
a. DTCs other than DTC P0300 / P0301 / P0302 / P0303 / P0304 / P0305 / P0306 (Misfire detected)
b. DTC P0300 / P0301 / P0302 / P0303 / P0304 / P0305 / P0306 (Misfire detected)

- Be sure to read Precaution for CAN Communication System before inspection Service Precautions and observe what is written there.
- ECM Replacement
When ECM is replaced with new one or substituted one, check for the following conditions. Neglecting this check may cause damage to ECM.
- Resistance value of all relays and actuators are as specified respectively.
- APP sensor, TP sensor, CMP sensor, CKP sensor, A/C refrigerant pressure sensor and fuel tank pressure sensor are in good condition and none of power circuits of these sensors is shorted to ground.

- VIN (vehicle identification number) data registration after ECM replacement
When ECM is replaced with new one (VIN data is still not registered) or with used one (VIN data of other vehicle has been registered previously), make sure that re-register VIN data correctly by performing VIN Registration.
- Communication of ECUs (included in ECM) is established by CAN (Controller Area Network).
Therefore, handle CAN communication line with care. For details, refer to CAN Communication System Description. CAN Communication System Description
- Immobilizer transponder code registration after replacing ECM
When ECM is replaced with new one or substituted one, make sure to register immobilizer transponder code.