Nissan Altima 2007-2012 Service Manual: P0603 ECM Power supply

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.

DTC Logic


DTC Logic

DTC DETECTION LOGIC

DTC CONFIRMATION PROCEDURE


DTC CONFIRMATION PROCEDURE

1.PRECONDITIONING

If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at least 10 seconds before conducting the next test.

>> GO TO 2.

2.PERFORM DTC CONFIRMATION PROCEDURE

1. Turn ignition switch ON and wait at least 1 second.

2. Start engine and let it idle for 1 second.

3. Turn ignition switch OFF, wait at least 10 seconds, and then turn ON.

4. Repeat steps 2 and 3 for four times.

5. Check 1st trip DTC.

Is 1st trip DTC detected? YES >> Go to EC-357, "Diagnosis Procedure".

NO >> INSPECTION END

Diagnosis Procedure

1.CHECK ECM POWER SUPPLY

1. Turn ignition switch OFF.

2. Disconnect ECM harness connector.

3. Check the voltage between ECM harness connector and ground.


Is the inspection result normal?


Is the inspection result normal? YES >> GO TO 3.

NO >> GO TO 2.

2.DETECT MALFUNCTIONING PART

Check the following.

    P0550 PSP Sensor
    Description Power steering pressure (PSP) sensor is installed to the power steering high-pressure tube and detects a power steering load. This sensor is a potentiometer which transforms the po ...

    P0605 ECM
    Description The ECM consists of a microcomputer and connectors for signal input and output and for power supply. The ECM controls the engine. DTC Logic DTC DETECTION LOGIC DTC CONFIRMATION P ...

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    Noise
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    Tire pressure receiver
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