Description
ECM has the memory function of the DTC memory, the air-fuel ratio feedback compensation value memory, the Idle Air Volume Learning value memory, etc. even when the ignition switch is turned OFF.

DTC DETECTION LOGIC
| DTC No. | Trouble diagnosis | DTC detecting condition | Possible cause |
|
P0603 |
ECM BACK UP/CIRCUIT (ECM power supply circuit) | ECM back-up RAM system does not function properly. |
|
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always perform the following procedure before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
Is 1st trip DTC detected?
YES >> Go to EC, "Diagnosis Procedure".
NO >> INSPECTION END
1.INSPECTION START
Is the 1st trip DTC P0603 displayed again?
YES >> GO TO 2.
NO >> INSPECTION END
2.REPLACE ECM
>> INSPECTION END
Parking brake system
Inspection and Adjustment
INSPECTION
When parking brake lever is operated with a force of 196 N (20 kg-f,
44 lb-f), make sure parking brake lever stroke is within the specified
number of notches. (Check it by listening and counting ratchet
clicks.)
Number of notches : Refer to PB "Park ...
Key switch (BCM Input)
Diagnosis Procedure
Regarding Wiring Diagram information, refer to DLK "Wiring Diagram".
1.CHECK KEY SWITCH INPUT SIGNAL
With CONSULT
Check key switch "KEY ON SW" in DATA MONITOR mode with CONSULT. Refer to BCS
"DOOR LOCK :
...