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TROUBLESHOOTING MULTIPORT FUEL INJECTION (MPI) 13A-131 OPERATION • Power is supplied to the injector (terminal No. 1) from the engine control relay (terminal No. 1). • The engine-ECU <M/T> or engine-A/T-ECU <A/T> (terminal No. 21) makes the power FUNCTION • The engine-ECU <M/T> or engine-A/T-ECU <A/T> connector controls the power supply • The fuel injection amount of the injector depends on the power supply interval. TROUBLE JUDGMENT Check Condition • While engine is running. Judgment Criterion • Injector coil surge voltage (battery positive voltage + 2 V) has not been detected for 2 PROBABLE CAUSE • Failed No. 4 injector • Open/short circuit in No. 4 injector circuit or loose connector contact • Failed engine-ECU <M/T> • Failed engine-A/T-ECU <A/T> DIAGNOSIS PROCEDURE STEP 1. MUT-III actuator test • Item 04: No. 4 injector OK: Idling state varies. Q: Is the check result normal? YES : Intermittent malfunction (Refer to GROUP 00 − How to Use Troubleshooting/Inspection Service Points ). NO : Go to Step 2 . STEP 2. Connector check: B-105 No. 4 injector Q: Is the check result normal? YES : Go to Step 3 . NO : Repair or replace. STEP 3. Check No. 4 injector itself. • Check No. 4 Injector (Refer to ) itself. Q: Is the check result normal? YES : Go to Step 4 . NO : Replace No. 4 injector. STEP 4. Perform voltage measurement at B-105 • Disconnect connector, and measure at harness side. • Ignition switch: ON • Voltage between terminal No. 1 and earth. OK: System voltage Q: Is the check result normal? YES : Go to Step 6 . NO : Go to Step 5 . AK300978 M 1 2 AM B-105 (GR) Harness side connector Connector: B-105 AK300978 M 1 2 AM B-105 (GR) Harness side connector Connector: B-105 |