P2127 – Accelerator Pedal Position Sensor (sub) Circuit Low Input MMC L200 IV



OPERATION

  • A power voltage of 5 V is applied to the accelerator pedal position sensor (terminal No. 4) from the engine-ECU (terminal No. 134).
  • The power voltage is earthed to the engine-ECU (terminal No. 136) from the accelerator pedal position sensor (terminal No. 5).
  • The sensor signal is inputted to the engine-ECU (terminal No. 135) from the accelerator pedal position sensor output terminal (terminal No. 6).

  • FUNCTION

  • The accelerator pedal position sensor (sub) outputs voltage which corresponds to the accelerator pedal depression.
  • The engine-ECU checks whether the voltage is within a specified range.

  • TROUBLE JUDGEMENT

  • Ignition switch is in “ON” position
  • Accelerator pedal position sensor (main) is normal
  • Accelerator pedal position sensor (sub) output voltage is lower than 0.125 V for 0.3 seconds.

  • PROBABLE CAUSES

  • Failed accelerator pedal position sensor
  • Open/short circuit or harness damage in accelerator pedal position sensor circuit or loose connector contact
  • Failed engine-ECU

  • DIAGNOSIS PROCEDURE

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

  • Item 10: Accelerator pedal position sensor (sub)
  • Q. Is the check result normal?

    STEP 2. Connector check: C-115 accelerator pedal position sensor connector

    Q. Is the check result normal?

    STEP 3. Perform voltage measurement at C-115 accelerator pedal position sensor connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 4 and earth.
  • Q. Is the check result normal?

    STEP 4. Connector check: C-103 engine-ECU connector

    Q. Is the check result normal?

    STEP 5. Check harness between C-115 (terminal No. 4) accelerator pedal position sensor connector and C-103 (terminal No. 134) 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 10: Accelerator pedal position sensor (sub)
  • Q. Is the check result normal?

    STEP 7. Perform resistance measurement at C-115 accelerator pedal position sensor connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 5 and earth.
  • Q. Is the check result normal?

    STEP 8. Connector check: C-103 engine-ECU connector

    Q. Is the check result normal?

    STEP 9. Check harness between C-115 (terminal No. 5) accelerator pedal position sensor connector and C-103 (terminal No. 136) engine-ECU connector.

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

    STEP 10. Connector check: C-103 engine-ECU connector

    Q. Is the check result normal?

    STEP 11. Perform voltage measurement at C-115 accelerator pedal position sensor connector.

  • Use special tool test harness (MB991658) to connect connector, and measure at pick-up harness.
  • Ignition switch: ON
  • Voltage between terminal No. 6 and earth.
  • Q. Is the check result normal?

    STEP 12. Connector check: C-103 engine-ECU connector

    Q. Is the check result normal?

    STEP 13. Check harness between C-115 (terminal No. 6) accelerator pedal position sensor connector and C-103 (terminal No. 135) engine-ECU connector.

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

    STEP 14. Check harness between C-115 (terminal No. 4) accelerator pedal position sensor connector and C-103 (terminal No. 134) engine-ECU connector.

  • Check power supply line for damage.
  • Q. Is the check result normal?

    STEP 15. Check harness between C-115 (terminal No. 6) accelerator pedal position sensor connector and C-103 (terminal No. 135) engine-ECU connector.

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

    Author: admin