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 "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

Refer to "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 "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 "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT (ECM) : Special Repair
Requirement".
- INSPECTION END