POWER STEERING SYSTEM (w/ VSC) FAIL-SAFE CHART

If a problem occurs in the power steering system, the power steering warning light in the combination meter comes on and the power steering assist is stopped, locked at a particular point or decreased simultaneously to protect the system.

Power Steering System
DTC Code Detection Condition Fail-safe Operation
C1531 Short circuit between power steering solenoid valve terminals SOF+ and ground Assist force is restricted.
Short circuit between power steering solenoid valve terminals SOF- and ground Power assist continues as normal.
Short circuit between power steering solenoid valve terminals SOF+ and SOF- Assist force is restricted.
Power steering solenoid valve open circuit Assist force is restricted.
C1231 Steering angle sensor circuit malfunction The power steering system is limited depending on which ECU has lost communication. For details, refer to Fail-safe Function.
C1544 Engine speed signal malfunction
C1547 Vehicle speed signal malfunction
U0073 Control module communication bus off

  1. FAIL-SAFE FUNCTION

    If the power steering ECU cannot receive the steering angle signal, steering zero point memory, vehicle speed signal or engine speed signal, the power steering warning light in the combination meter illuminates and the vehicle enters fail-safe mode.

    Malfunction Area Fail-Safe Mode
    Steering Angle Signal Steering Zero Point Memory Vehicle Speed Signal Engine Speed Signal
    X - - -

    • V-Q control fixed

    • Steering angle compensation disabled

    • Steering wheel return compensation disabled

    • Engine speed compensation normal
    - X - -

    • V-Q control normal

    • Steering angle compensation disabled

    • Steering wheel return compensation disabled

    • Engine speed compensation normal
    - - X - Assume vehicle speed 40 km/h (25 mph) and control each compensation
    - - - X

    • V-Q control normal

    • Steering angle compensation normal

    • Steering wheel return compensation normal

    • Engine speed compensation disabled
    X X - -

    • V-Q control fixed

    • Steering angle compensation disabled

    • Steering wheel return compensation disabled

    • Engine speed compensation normal
    X - X - Constant fluid volume
    X - - X

    • V-Q control characteristics fixed

    • Steering angle compensation disabled

    • Steering wheel return compensation disabled

    • Engine speed compensation disabled
    - X X -

    • V-Q control fixed

    • Steering angle compensation disabled

    • Steering wheel return compensation disabled

    • Engine speed compensation normal
    - X - X

    • V-Q control normal

    • Steering angle compensation disabled

    • Steering wheel return compensation disabled

    • Engine speed compensation disabled
    - - X X

    • Assume vehicle speed 40 km/h (25 mph) and control each compensation

    • Engine speed compensation disabled
    - X X X

    • V-Q control characteristics fixed

    • Steering angle compensation disabled

    • Steering wheel return compensation disabled

    • Engine speed compensation disabled
    X - X X Constant fluid volume
    X X - X

    • V-Q control characteristics fixed

    • Steering angle compensation disabled

    • Steering wheel return compensation disabled

    • Engine speed compensation disabled
    X X X - Constant fluid volume
    X X X X Constant fluid volume

    Tech Tips

    X: Malfunction