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:

    Positive crankcase ventilation
    Description This system returns blow-by gas to the intake manifold. The positive crankcase ventilation (PCV) valve is provided to conduct crankcase blow-by gas to the intake manifold. During partial throttle operation of the engine, the intake manifold sucks the blow-by gas via the PCV ...

    Door outside molding
    Removal and Installation 1. Front door outside molding 2. Front door Door Outside Molding Removal 1. Open the front door window fully. 2. Remove the side view mirror. Refer to MIR-19, "Removal and Installation". 3. Lift and twist front door molding from rear end, disconnect ...

    Anti-pinch system does not operate normally (driver side)
    Diagnosis Procedure 1. PERFORM INITIALIZATION PROCEDURE Perform initialization procedure. Refer to PWC-295, "ADDITIONAL SERVICE WHEN REPLACING CONTROL UNIT : Special Repair Requirement". Is the inspection result normal? YES >> GO TO 2 NO >> Repair or replace the mal ...