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
Servicing air conditioner
The air conditioner system in your NISSAN vehicle
is charged with a refrigerant designed with
the environment in mind.
This refrigerant does not harm the earth's
ozone layer.
Special charging equipment and lubricant is required
when servicing your NISSAN air conditioner.
Using improper ...
Multiport fuel injection system
MULTIPORT FUEL INJECTION SYSTEM : System Diagram
MULTIPORT FUEL INJECTION SYSTEM : System
Description
INPUT/OUTPUT SIGNAL CHART
Sensor
Input signal to ECM
ECM function
Actuator
Crankshaft position sensor (POS)
Engine speed*4
Piston position
Fuel injection & ...