Home 5 Chassis 5 Power Steering 5 9. C1568, EPS Power Steering | 2006 Lexus RX400h

C1568, Power Steering Inoperative | Lexus RX400h


🚗 2006 Lexus RX400h

The power steering is not working.

  • EPS: C1568 DC-DC converter malfunction

🩺 Diagnosis

Possible causes of C1568
  • Power Steering Converter
  • Hybrid Control System
  • EPS DDC fuse
  • Wire harness or connector
  • Power Steering Connector ground
  • Power Steering ECU Assembly
Location of Power Steering ECU
  • Power Steering ECU location | 2006 Lexus RX400h


Wiring Diagram
  • Power Steering wiring diagram | 2006 Lexus RX400h  Power Steering wiring diagram | 2006 Lexus RX400h
  • Check for 42 volts on the White wire at the Power Steering ECU connector (P47 – 1).
    • If there is voltage, the converter is good. Suspect Power Steering ECU.
    • If there is no voltage, disconnect Power Steering ECU connector, start the car, and apply 12V to Yellow/Black wire (P41 – 11).  This is 12 volts coming from the Power Steering ECU to tell the Power Steering Converter to output the 42 volts. 42V should now appear at the White wire (P47 – 1).
      • If there is no voltage,  verify that between the Red wire and the Blue wire at the Power Steering Converter there is at least 288V when the ready light is on. Check fuse if there is no voltage. Fuse is replaced together with the Main Relay.
      • If there is voltage, check Power Steering ECU power and grounds. If OK, replace Power Steering ECU.

After replacing old PSU Module with the new one, it will need to be calibrated (Torque Sensor), otherwise, it won’t work.


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