POWER STEERING SYSTEM(w/ Variable Flow Control Solenoid Valve) FAIL-SAFE CHART

If a problem occurs in the power steering system, the power steering warning light in the combination meter comes on and 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
C15F0 Short circuit between variable flow control solenoid valve terminal SOF+ and ground Assist force is restricted.
Short circuit between variable flow control solenoid valve terminal SOF- and ground Power assist continues as normal.
Short circuit between variable flow control solenoid valve terminals SOF+ and SOF- Assist force is restricted.
Power steering solenoid valve open circuit Assist force is restricted.
C15F1 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.
C15F2 VGRS system malfunction
C1541 Vehicle speed signal malfunction
C1544 Engine speed signal malfunction
U0100 Lost communication with ECM/PCM "A"
U0126 Lost communication with steering angle sensor module
U0129 Lost communication with brake system control module
U0130 Lost communication with steering effort control module

  1. FAIL-SAFE FUNCTION

    If the power steering ECU cannot receive the steering angle signal, VGRS relative 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 / VGRS relative 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 - Vehicle speed of 40 km/h (25 mph) assumed and each compensation performed
    - - - 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 - Fluid flow maintained at constant rate
    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

    • Vehicle speed of 40 km/h (25 mph) assumed and each compensation performed

    • 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 Fluid flow maintained at constant rate
    X X - X

    • V-Q control characteristics fixed

    • Steering angle compensation disabled

    • Steering wheel return compensation disabled

    • Engine speed compensation disabled
    X X X - Fluid flow maintained at constant rate
    X X X X Fluid flow maintained at constant rate

    Tech Tips

    X: Malfunction