Nissan Altima 2007-2012 Service Manual: Function diagnosis

EPS SYSTEM

System Diagram

CONTROL DIAGRAM

System Description

• The EPS system controls the power steering solenoid valve through the power steering control unit.

• The valve driving voltage to control the power steering solenoid valve varies according to the vehicle speed.

OPERATION PRINCIPLE

During Parking (When Turning The Steering Wheel To The Right)

1. Power steering solenoid valve is closed while a vehicle is stopped.

2. Pinion "1R", "2R" and "3R" are closed depending on steering torque of steering wheel.

3. Oil pressure "P" in the gear housing assembly is the sum of oil pressures occurred in "2R" and "3R". This results in a light steering force because of high pressure.

During High-speed Operation

1. Power steering solenoid valve is opened during high-speed operation.

2. Pinion "1R", "2R" and "3R" are closed depending on steering torque of steering wheel.

3. Oil pressure "2R" does not occur because the power steering solenoid valve is on full throttle.

4. Oil pressure "P" in the gear housing assembly includes only oil pressure occurred in "3R" and results in a heavy steering force.

Component Parts Location

1. Power steering control unit M59 (view with glove box removed)

2. Power steering solenoid valve E14

Component Description

    Basic inspection
    DIAGNOSIS AND REPAIR WORKFLOW Work Flow DETAILED FLOW 1.COLLECT THE INFORMATION FROM THE CUSTOMER It is also important to clarify customer complaints before inspection. First of all, reproduce s ...

    Other materials:

    Ground
    Ground Distribution MAIN HARNESS ENGINE ROOM HARNESS FRONT END MODULE HARNESS ENGINE CONTROL HARNESS BODY HARNESS BODY NO. 2 HARNESS HARNESS Harness Layout HOW TO READ HARNESS LAYOUT The following Harness Layouts use a map style grid to help locate connectors on the drawi ...

    Power generation voltage variable control system operation inspection
    Inspection Procedure CAUTION: When performing this inspection, always use a charged battery that has completed the battery inspection. (When the charging rate of the battery is low, the response speed of the voltage change will become slow. This can cause an incorrect inspection.) 1.CHECK ...

    Door switch
    Description Detects door open/close condition and transmits the signal to BCM. Component Function Check 1. CHECK DOOR SWITCH INPUT SIGNAL Check (“DOOR SW-DR” and “DOOR SW-AS”) in “DATA MONITOR” mode with CONSULT-III. Refer to BCS- 34, "RETAINED PWR : CONSULT-III Function (BC ...