Nissan Altima 2007-2012 Service Manual: ECM branch line circuit

Diagnosis Procedure

INSPECTION PROCEDURE

1.CHECK CONNECTOR

1. Turn the ignition switch OFF.

2. Disconnect the battery cable from the negative terminal.

3. Check the following terminals and connectors for damage, bend and loose connection (unit side and connector side).

- ECM

- Harness connector E30

- Harness connector M1

Is the inspection result normal? YES >> GO TO 2.

NO >> Repair the terminal and connector.

2.CHECK HARNESS FOR OPEN CIRCUIT

1. Disconnect the connector of ECM.

2. Check the resistance between the ECM harness connector terminals.

Is the measurement value within the specification? YES >> GO TO 3.

NO >> Repair the ECM branch line.

3.CHECK POWER SUPPLY AND GROUND CIRCUIT

Check the power supply and the ground circuit of the ECM. Refer to the following.

• QR engine models for California: EC-144, "Diagnosis Procedure" • QR engine models expect for California: EC-673, "Diagnosis Procedure" • VQ engine models: EC-1175, "Diagnosis Procedure" Is the inspection result normal? YES (Present error)>>Replace the ECM. Refer to the following.

• QR engine models for California: EC-27, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Requirement" • QR engine models except for California: EC-563, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Requirement" • VQ engine models: EC-1051, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Requirement" YES (Past error)>>Error was detected in the ECM branch line.

NO >> Repair the power supply and the ground circuit.

    Main line between dlc and abs circuit
    Diagnosis Procedure INSPECTION PROCEDURE 1.CHECK CONNECTOR 1. Turn the ignition switch OFF. 2. Disconnect the battery cable from the negative terminal. 3. Check the following terminals and co ...

    A-BAG branch line circuit
    Diagnosis Procedure 1.CHECK AIR BAG DIAGNOSIS SENSOR UNIT Check the air bag diagnosis sensor unit. Refer to SRC-3, "Work Flow". Is the inspection result normal? YES >> Replace t ...

    Other materials:

    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 power steering load into output voltage, and emits the voltage signal to the ECM. The ECM controls t ...

    P1574 ASCD Vehicle speed sensor
    Description The ECM receives two vehicle speed signals via CAN communication line. One is sent from combination meter, and the other is from TCM (Transmission control module). The ECM uses these signals for ASCD control. Refer to EC-603, "System Description" for ASCD functions. D ...

    Normal operating condition
    Description FUEL CUT CONTROL (AT NO LOAD AND HIGH ENGINE SPEED) If the engine speed is above 1,400 rpm under no load (for example, the selector lever position is P or N and engine speed is over 1,400 rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies ba ...