P0603

DTC P0603 ECM POWER SUPPLY





Component 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.




On Board Diagnosis Logic









DTC Confirmation Procedure
1. If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and wait at least 10 seconds.
3. Turn ignition switch OFF, wait at least 5 minutes.
4. Turn ignition switch ON and wait at least 10 seconds.
5. Repeat steps 2 and 3 for five times.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to P0603.




Wiring Diagram





Specification data are reference values and are measured between each terminal and ground.

CAUTION:
Never use ECM ground terminals when measuring input/output voltage. Doing so may result in damage to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.









Diagnosis Procedure
1.CHECK ECM POWER SUPPLY
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.





3. Check voltage between ECM terminal 121 and ground with
CONSULT-III or tester.

Voltage: Battery voltage

OK or NG
OK - GO TO 3.
NG - GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
- Harness connectors E108, M15
- 20 A fuse
- IPDM E/R harness connector E8
- Harness for open or short between ECM and battery
- Repair or replace harness or connectors.
3.CHECK INTERMITTENT INCIDENT
Diagnosis Procedure.
OK or NG
OK - GO TO 4.
NG - 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 P0603.
4. Is the 1st trip DTC P0603 displayed again?
Yes or No
Yes - GO TO 5.
No - INSPECTION END
5.REPLACE ECM
1. Replace ECM.
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. .
3. Perform Testing and Inspection.
4. Perform .
5. Perform Throttle Valve Closed Position Learning.
6. Perform Testing and Inspection.
- INSPECTION END