Computers and Control Systems: Service Precautions

PRECAUTION IN DIAGNOSING TROUBLE
- Don't disconnect couplers from Electronic Control Module (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.
- Diagnostic information stored in ECM memory can be cleared as well as checked by using SUZUKI scan tool (Tech-1) or OBD- II 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.
- Priorities for diagnosing troubles. If troubleshooting priorities for multiple diagnostic code are given in the applicable diagnostic chart, these should be followed. If no instructions are given, troubleshoot diagnostic trouble codes according to the following priorities.
1. Diagnostic trouble codes other than fuel trim malfunction (DTC P0171, P0172), EGR (DTC P0400), and misfire (DTC P0300 - P0304).
2. Fuel trim malfunction (DTC P0171, P0172) and EGR (DTC P0400).
3. Misfire (DTC P0300 - P0304)