ECM Precautions

1. Before connecting or disconnecting the ECM harness connector to or from any ECM, be sure to turn the ignition switch to the "OFF" position and disconnect the negative battery terminal in order not to damage the ECM as battery voltage is applied to the ECM even if the ignition switch is turned off. Failure to do so may damage the ECM.




2. When connecting the ECM harness connector, tighten securing bolt until red projection is in line with connector face.




3. When connecting or disconnecting pin connectors into or from ECM, take care not to damage pin terminals (bend or break).
4. Make sure that the pin terminals are not bent or broken before reconnecting.




5. Before replacing the ECM, perform ECM input/output signal inspection and make sure whether ECM functions properly or not.




6. After performing the "Diagnostic Procedure", perform ECCS on-board diagnostic system and driving test.




7. When measuring ECM controlled components supply voltage with a circuit tester, separate one tester probe from the other. If the two tester probes accidentally make contact with each other during measurement, the circuit will be shorted resulting in damage to the ECM power transistor.