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 DETECTION LOGIC
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? YES >> GO TO 3.
NO >> GO TO 2.
2.DETECT MALFUNCTIONING PART
Check the following.
• 15A fuse (No. 42) • IPDM E/R harness connector F10
• Harness for open or short between ECM and battery
>> Repair or replace harness or connectors.
3.CHECK INTERMITTENT INCIDENT
Refer to GI-42, "Intermittent Incident".
Is the inspection result normal? YES >> GO TO 4.
NO >> Repair or replace harness or connectors.
4.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Select “SELF-DIAG RESULTS” mode with CONSULT-III.
3. Touch “ERASE”.
4. Perform DTC CONFIRMATION PROCEDURE.
See EC-357, "DTC Logic".
1. Turn ignition switch ON.
2. Select Service $04 with GST.
3. Perform DTC CONFIRMATION PROCEDURE.
See EC-357, "DTC Logic".
Is the 1st trip DTC P0603 displayed again? YES >> GO TO 5.
NO >> INSPECTION END
5.REPLACE ECM
1. Replace ECM.
2. Go to EC-27, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Requirement".
>> INSPECTION END
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 ...
Other materials:
Rear view camera
Removal and Installation
REMOVAL
1. Remove the license plate finisher. Refer to EXT-23, "Removal and
Installation" (coupe) and EXT-46,
"Removal and Installation" (sedan).
2. Remove trunk lid finisher. Refer to INT-22, "Exploded View".
3. Remove the rear view ...
Starting the engine
1. Apply the parking brake.
2. Move the shift lever to P (Park) or N (Neutral).
P (Park) is recommended.
The starter is designed not to operate if
the shift lever is in any of the driving
positions.
3. Push the ignition switch to the ON position.
Depress the brake pedal and push the ign ...
Changing engine oil
QR25DE engine
1. Park the vehicle on a level surface and apply
the parking brake.
2. Start the engine and let it idle until it reaches
operating temperature, then turn it off.
3. Remove the oil filler cap A by turning it
counterclockwise.
4. Place a large drain pan under the drain plug
B . ...