P0603

P0603 ECM POWER SUPPLY





Description





Battery voltage is supplied to the ECM even when the ignition switch is turned OFF for the ECM memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the idle air volume learning value memory, etc.




DTC Logic

DTC DETECTION LOGIC






DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Turn ignition switch OFF and wait at least 10 seconds.
- GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON and wait at least 10 second.
2. Turn ignition switch OFF and wait at least 5 minutes.
3. Turn ignition switch ON and wait at least 10 second.
4. Repeat steps 2 and 3 for five times.
5. Check 1st trip DTC.
Is 1st trip DTC detected?
YES - Go to SEE Diagnosis Procedure.
NO - INSPECTION END




Diagnosis Procedure
1.CHECK ECM POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the voltage between ECM harness connector terminals as per the following.





Is the inspection result normal?
YES - GO TO 3.
NO - GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E3, F1
- 15 A fuse (No. 50)
- IPDM E/R harness connector E7
- Harness for open or short between ECM and battery
- Repair or replace harness or connectors.
3.CHECK INTERMITTENT INCIDENT
Intermittent Incident.
Is the inspection result normal?
YES - GO TO 4.
NO - Repair or replace harness or connectors.
4.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Erase DTC.
3. Perform DTC Confirmation Procedure.
See SEE DTC Logic.
Is the 1st trip DTC P0603 displayed again?
YES - GO TO 5.
NO - INSPECTION END
5.REPLACE ECM
1. Replace ECM.
2. Go to Special Repair Requirement.
- INSPECTION END