ECM Power Supply Except For California

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

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


Wiring Diagram






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

CAUTION:
Do not 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.Check voltage between ECM terminal 66 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.
- Harness connectors E17, F10
- 20 A fuse
- Harness for open or short between ECM and battery
- Repair or replace harness or connectors.

3. CHECK INTERMITTENT INCIDENT

Refer to Trouble Diagnosis For Intermittent Incident.
OK or NG
OK- GO TO 4.
NG- Repair or replace harness or connectors.

4. PERFORM DTC CONFIRMATION PROCEDURE

1.Erase DTC.
2.Perform DTC Confirmation Procedure.
See .
Is the 1st trip DTC P0603 displayed again?
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.
ECM Re-Communicating Function.
3.Perform For California.
4.Perform For California.
5.Perform For California.
6.Perform For California.
-INSPECTION END