P0123 – Throttle Position Sensor Circuit High Input MMC L200 IV



OPERATION

  • A power voltage of 5 V is applied to the electronic-controlled throttle valve (terminal No. 2) from the engine-ECU (terminal No. 93).
  • The power voltage is earthed to the engine-ECU (terminal No. 34) from the electronic-controlled throttle valve (terminal No. 4).
  • The sensor signal is inputted to the engine-ECU (terminal No. 40) from the electronic-controlled throttle valve output terminal (terminal No. 1).

  • FUNCTION

  • The throttle position sensor converts the throttle valve position into voltage and inputs it into the engine-ECU.
  • The engine-ECU control the throttle valve position.

  • TROUBLE JUDGMENT

  • Battery positive voltage is 8 – 16 V
  • 2 seconds later after the ignition switch has been in “ON” position or the engine has started up
  • The throttle position sensor output voltage is 4.85 V or more for 0.5 second.

  • PROBABLE CAUSES

  • Failed throttle position sensor
  • Open circuit or harness damage in throttle position sensor circuit or loose connector contact
  • Failed engine-ECU

  • DIAGNOSIS PROCEDURE

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

  • Item 45: Throttle position sensor
  • Q. Is the check result normal?

    STEP 2. Connector check: A-132 electronic-controlled throttle valve connector

    Q. Is the check result normal?

    STEP 3. Perform resistance measurement at A-132 electronic-controlled throttle valve connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 4 and earth.
  • Q. Is the check result normal?

    STEP 4. Connector check: C-105 engine-ECU connector

    Q. Is the check result normal?

    STEP 5. Check harness between A-132 (terminal No. 4) electronic-controlled throttle valve connector and C-105 (terminal No. 34) engine-ECU connector.

  • Check earthing line for open circuit and damage.
  • Q. Is the check result normal?

    STEP 6. M.U.T.-III data list

  • Item 45: Throttle position sensor
  • Q. Is the check result normal?

    STEP 7. Replace the electronic-controlled throttle valve assembly

  • After replacing the electronic-controlled throttle valve assembly, re-check the trouble symptoms.
  • Q. Is the check result normal?

    Author: admin