Precautions In Diagnosing Trouble

PRECAUTIONS IN DIAGNOSING TROUBLE

- Don't disconnect couplers 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 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 two or more (DTCs) are stored, proceed to the DTC flow which has detected earliest in the order and follow the instruction in that flow.
If no instructions are given, troubleshoot DTCs according to the following priorities.
- Diagnostic trouble codes (DTCs) other than DTC P0171 / P0172 (Fuel system too lean / too rich), DTC P0300 / P0301 / P0302 / P0303 / P0304 (Misfire detected) and DTC P0401 / P0402 (EGR flow malfunction)
- DTC P0171 / P0172 (Fuel system too lean / too rich) and DTC P0401 / P0402 (EGR flow malfunction)
- DTC P0300 / P0301 / P0302 / P0303 / P0304 (Misfire detected)
- Be sure to read Precautions for Electrical Circuit Service before inspection and observe what is written there.
- ECM Replacement
When substituting a known-good ECM, check for the following conditions. Neglecting this check may cause damage to a known-good ECM.
- Resistance value of all relays, actuators is as specified respectively.
- MAP sensor, TP sensor and EVAP leak check pressure sensor (built-in EVAP leak check module) (with ORVR system) 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.
Otherwise, MIL remains on even if the engine started or it causes the inconsistency between registered VIN data in ECM and actual VIN.