Nissan Altima (L32) 2007-2012 Service Manual: ECU diagnosis

11

POWER STEERING CONTROL UNIT

Reference Value

TERMINAL LAYOUT

PHYSICAL VALUES

CAUTION: When using circuit tester or oscilloscope to measure voltage for inspection, be sure not to extend forcibly any connector terminals.

Wiring Diagram — ELECTRONICALLY CONTROLLED POWER STEERING SYSTEM

Fail Safe

EPS system

• EPS system enters the fail-safe mode (that allows the steering force to be controlled without impairing the drive ability) if any of the input/output signals to/from EPS system (power steering control unit) deviate from the standard.

NOTE: The system enters the fail-safe mode if the engine speed remains at 1,500 rpm or more for over 10 seconds while the vehicle is stopped. This is normal.

• The fail-safe function is canceled when a vehicle speed signal of 2 km/h (1.2 MPH) or more is inputted or the key switch is turned OFF→ ON. EPS system restores the normal operation at that time.

    Vehicle speed signal circuit
    Description • Combination meter sends vehicle speed signal to power steering control unit. Diagnosis Procedure 1.PERFORM COMBINATION METER SELF-DIAGNOSIS Perform combination meter self-diagno ...

    Symptom diagnosis
    UNBALANCE STEERING WHEEL TURNING FORCE (TORQUE VARIATION) Description • Hard steering when fully turning the steering wheel. • Light steering when driving at a high speed. Diagnosis Proce ...

    Other materials:

    P1778 step motor - function
    Description • The step motor's 4 aspects of ON/OFF change according to the signal from TCM. As a result, the flow of line pressure to primary pulley is changed and pulley ratio is controlled. • This diagnosis item is detected when electrical system is OK, but mechanical system is NG. ...

    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 connectors for damage, bend and loose connection (connector side and harness side). - Harness co ...

    C1708 - c1711 data from transmitter not being received
    Description Tire pressure data for one or more transmitters is not being received by the BCM. DTC Logic DTC DETECTION LOGIC DTC CONFIRMATION PROCEDURE 1.ID REGISTRATION AND VEHICLE DRIVING 1. Carry out ID registration of all transmitters. 2. Drive at a speed of 40 km/h (25 MPH) or more ...