Posted in Mitsubishi Colt

P0123 – Throttle Position Sensor (Main) Circuit High Input 134 MMC Colt

 Posted by  Posted on September 26, 2020

OPERATION

  • A power voltage of 5 V is applied to the electronic-controlled throttle valve (terminal No. 5) from the engine-ECU (terminal No. 31).
  • The power voltage is earthed to the engine-ECU (terminal No. 30) from the electronic-controlled throttle valve (terminal No. 3).
  • The sensor signal is inputted to the engine-ECU (terminal No. 15) from the electronic-controlled throttle valve output terminal (terminal No. 6).

    • FUNCTION

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

    • TROUBLE JUDGMENT

  • Ignition switch is in “ON” position.
  • Throttle position sensor (main) output voltage is 4.8 V or more for 0.5 second.

    • PROBABLE CAUSES

  • Failed throttle position sensor (main)
  • Open throttle position sensor (main) circuit, harness damage, or connector damage
  • Failed engine-ECU

    • DIAGNOSIS PROCEDURE

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

  • Item No. 13: Throttle position sensor (main)

    • Q. Is the check result normal?

    STEP 2. Connector check: A-118 electronic-controlled throttle valve connector

    Q. Is the check result normal?

    STEP 3. Perform voltage measurement at A-118 electronic-controlled throttle valve connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 5 and earth.

    • Q. Is the check result normal?

    STEP 4. Connector check: A-08 engine-ECU connector

    Q. Is the check result normal?

    STEP 5. Check harness between A-118 (terminal No. 5) electronic-controlled throttle valve connector and A-08 (terminal No. 31) engine-ECU connector.

  • Check power supply line for open/short circuit.

    • Q. Is the check result normal?

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

  • Item No. 13: Throttle position sensor (main)

    • Q. Is the check result normal?

    STEP 7. Perform resistance measurement at A-118 electronic-controlled throttle valve connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 3 and earth.

    • Q. Is the check result normal?

    STEP 8. Connector check: A-08 engine-ECU connector

    Q. Is the check result normal?

    STEP 9. Check harness between A-118 (terminal No. 3) electronic-controlled throttle valve connector and A-08 (terminal No. 30) engine-ECU connector

  • Check earthing line for open circuit and damage.

    • Q. Is the check result normal?

    STEP 10. Connector check: A-08 engine-ECU connector

    Q. Is the check result normal?

    STEP 11. Check harness between A-118 (terminal No. 5) electronic-controlled throttle valve connector and A-08 (terminal No. 31) engine-ECU connector.

  • Check power supply line for damage.

    • Q. Is the check result normal?

    STEP 12. Check harness between A-118 (terminal No. 6) electronic-controlled throttle valve connector and A-08 (terminal No. 15) engine-ECU connector.

  • Check output line for open/short circuit and damage.

    • Q. Is the check result normal?

    STEP 13. M.U.T.-III data list

  • Item No. 13: Throttle position sensor (main)

    • Q. Is the check result normal?

    STEP 14. Replace the throttle body assembly

  • After replacing the throttle body assembly, reconfirm whether the diagnosis code is set.

    • Q. Is the diagnosis code set?

    Author: admin