P0603

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 step.
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, wait at least 10 seconds.
3.Turn ignition switch OFF, wait at least 5 minutes.
4.Turn ignition switch ON, wait at least 10 seconds.
5.Repeat steps 2 to 3 for 5 times.
6.Check 1st trip DTC.
7.If 1st trip DTC is detected, go to Diagnosis Procedure (see below).


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 or tester.
Voltage: Battery voltage
OK or NG
OK- GO TO 3.
NG- GO TO 2.

2. DETECT MALFUNCTIONING PART

Check the following.
- 20 A fuse (No.53)
- IPDM E/R harness connector E121
- Harness for open or short between ECM and battery
- Repair open circuit in harness or connectors.

3. CHECK INTERMITTENT INCIDENT

Intermittent Incident.
OK or NG
OK- GO TO 4.
NG- Repair or replace harness or connectors.

4. PERFORM DTC CONFIRMATION PROCEDURE

With CONSULT
1.Turn ignition switch ON.
2.Select "SELF DIAG RESULTS" mode with CONSULT.
3.Touch "ERASE".
4.Perform DTC Confirmation Procedure.
See .
5.Is the 1st trip DTC P0603 displayed again?
With GST
1.Turn ignition switch ON.
2.Select Service $04 with GST.
3.Perform DTC Confirmation Procedure.
See .
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 NVIS(NATS) system and registration of all NVIS(NATS) ignition key IDs. Refer to
Special Repair Requirement.
3.Perform VIN Registration.
4.Perform Accelerator Pedal Released Position Learning.
5.Perform Throttle Valve Closed Position Learning.
6.Perform Idle Air Volume Learning.
-INSPECTION END