POWER STEERING SYSTEM FAIL-SAFE CHART

If a problem occurs in the power steering system, the power steering assist will be stopped or the amount of power assist will be decreased to protect the system.

Power Steering System
Malfunction Fail-safe Operation

  • Torque sensor (electric power steering column sub-assembly) malfunction

  • Power steering motor (power steering ECU assembly) malfunction

  • Power steering ECU assembly malfunction

 Power steering assist stops or assist amount is limited

  • Vehicle speed signal malfunction

  • Skid control ECU (brake booster with master cylinder assembly) malfunction

  • History of power steering ECU assembly overheating

  • History of decrease in battery voltage (not malfunction)

 Power steering assist is temporarily limited

Tech Tips


  • The amount of power assist may be decreased to prevent the motor and ECUs from overheating if the steering wheel is continuously turned when the vehicle is either stopped or being driven at a low speed, or if the steering wheel is kept at either full lock position for a long time. In such cases, the amount of power assist returns to normal when the steering wheel is not turned for approximately 10 minutes with the engine idling.

  • If the battery is not sufficiently charged or the voltage decreases temporarily, the amount of power assist will be reduced and the EPS warning light will come on. In such cases, the amount of power assist returns to normal when the battery voltage recovers.