P0551 – Power Steering Fluid Pressure Switch System MMC L200 IV



OPERATION

  • The battery voltage is applied to the power steering pressure switch (terminal No. 1) from the engine-ECU (terminal No. 127)

  • FUNCTION

  • It is detected whether a load is applied on the power steering fluid pump by steering or not, and the signal is inputted to the engine-ECU. When the power steering fluid pressure switch “ON” signal (a large load on the power steering fluid pump) is inputted, the engine-ECU provides the idle-up control.

  • TROUBLE JUDGMENT

  • Within 5 seconds after the ignition switch is in the “OFF” position.
  • For 2 seconds, the power steering fluid pressure switch is in the “ON” position and the engine continuously stops.

  • PROBABLE CAUSES

  • Failed power steering fluid pressure switch
  • Short circuit in power steering fluid pressure switch circuit or loose connector contact
  • Failed engine-ECU

  • DIAGNOSIS PROCEDURE

    STEP 1. M.U.T.-III data list.

  • Item 75: Power steering fluid pressure switch
  • Q. Is the check result normal?

    STEP 2. Connector check: A-134 power steering pressure switch connector

    Q. Is the check result normal?

    STEP 3. Check power steering pressure switch itself.

  • Disconnect A-134 power steering fluid pressure switch connector.
  • Continuity between terminal No.1 and earth.
  • Q. Is the check result normal?

    STEP 4. Check at A-134 power steering fluid pressure switch connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No.1 and earth.
  • Q. Is the check result normal?

    STEP 5. Connector check: C-103 engine-ECU connector

    Q. Is the check result normal?

    STEP 6. Check harness between C-103 (terminal No. 127) engine-ECU connector and A-134 (terminal No. 1) power steering fluid pressure switch connector.

  • Check output line for short circuit.
  • Q. Is the check result normal?

    STEP 7. M.U.T.-III data list.

  • Item 75: Power steering fluid pressure switch
  • Q. Is the check result normal?

    Author: admin