Nissan Altima 2007-2012 Service Manual: ECU diagnosis

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:

    Front coil spring and strut
    Removal and Installation REMOVAL 1. Remove wheel and tire. Refer to WT-66, "Adjustment". 2. Remove brake caliper and reposition aside using wire. Refer to BR-30, "BRAKE CALIPER ASSEMBLY : Exploded View". CAUTION: Avoid depressing brake pedal with brake caliper removed ...

    ECU Diagnosis
    ECM Reference Value VALUES ON THE DIAGNOSIS TOOL Remarks: ●  Specification data are reference values. ●   Specification data are output/input values which are detected or supplied by the ECM at the connector. * Specification data may not be directly related to the ...

    Warning signals
    To help prevent the vehicle from moving unexpectedly by erroneous operation of the Intelligent Key or to help prevent the vehicle from being stolen, a chime or buzzer sounds from inside and outside the vehicle and a warning is displayed in the instrument panel. When a chime or beep sounds or ...