POWER STEERING SYSTEM DIAGNOSIS SYSTEM


  1. DESCRIPTION


    1. Connecting the intelligent tester to the vehicle and reading various data output from the power steering ECU is the only difference between usual troubleshooting procedures and those for a vehicle with a diagnostic system.

      The power steering ECU records DTCs when the ECU detects a malfunction in the computer itself or in its circuits.

      To check the DTCs, connect the intelligent tester to the DLC3. The intelligent tester enables you to erase the DTCs and check the freeze frame data and various forms of steering data.

  2. CHECK DLC3


    1. A01GKCJE77

      Check the DLC3.

      The ECU uses ISO 15765-4 for communication. The terminal arrangement of the DLC3 complies with ISO 15031-3 and matches the ISO 15765-4 format. If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.

      Terminal No. (Symbols) Terminal Description Condition Specified Condition
      SIL (7) - SG (5) Bus "+" line During transmission Pulse generation
      CG (4) - Body ground Chassis ground Always Below 1 Ω
      SG (5) - Body ground Signal ground Always Below 1 Ω
      BAT (16) - Body ground Battery positive Always 11 to 14 V
      CANH (6) - CANL (14) CAN bus line Engine switch off* 54 to 69 Ω
      CANH (6) - Battery positive HIGH-level CAN bus line Engine switch off* 6 kΩ or higher
      CANH (6) - CG (4) HIGH-level CAN bus line Engine switch off* 200 Ω or higher
      CANL (14) - Battery positive LOW-level CAN bus line Engine switch off* 6 kΩ or higher
      CANL (14) - CG (4) LOW-level CAN bus line Engine switch off* 200 Ω or higher

      Note

      *: Before measuring the resistance, leave the vehicle as is for at least 1 minute and do not operate the engine switch, any other switches or the doors.

      If the result is not as specified, the DLC3 may have a malfunction. Repair or replace the harness and connector.

      Tech Tips

      Connect the cable of the intelligent tester to the DLC3, turn the engine switch on (IG), and attempt to use the tester. If the display indicates that a communication error has occurred, there is a problem either with the vehicle or with the tester.


      • If communication is normal when the tester is connected to another vehicle, inspect the DLC3 on the original vehicle.

      • If communication is still not possible when the tester is connected to another vehicle, the problem may be in the tester itself. Consult the Service Department listed in the tester's instruction manual.

  3. CHECK PS WARNING LIGHT


    1. Check that the PS warning light comes on when the engine switch is on (IG), and goes off when the engine is started.

    2. If the warning light does not come on or remains on, inspect the PS warning light circuit.

      Trouble Area See procedure
      PS warning light circuit (Remains on)

      Click here