P0108 – Manifold Absolute Pressure Sensor Circuit High Input MMC L200 IV



OPERATION

  • A power voltage of 5 V is applied to the manifold absolute pressure sensor power terminal (terminal No. 1) from the engine-ECU (terminal No. 72) and earthed to the engine-ECU (terminal No. 31) from the manifold absolute pressure sensor (terminal No. 3).
  • The sensor signal is inputted to the engine-ECU (terminal No. 37) from the manifold absolute pressure sensor output terminal (terminal No. 2).

  • FUNCTION

  • The manifold absolute pressure sensor converts the manifold absolute pressure into a voltage signal and inputs the signal to the engine-ECU.
  • In response to the signal, the engine-ECU corrects the fuel injection amount, etc.

  • TROUBLE JUDGEMENT

  • 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 manifold absolute pressure sensor output voltage should exceed 4.72 V for 0.5 seconds.

  • PROBABLE CAUSES

  • Failed manifold absolute pressure sensor
  • Open circuit in manifold absolute pressure sensor circuit or loose connector contact
  • Failed engine-ECU

  • DIAGNOSIS PROCEDURE

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

  • Item 6: Manifold absolute pressure sensor
  • Q. Is the check result normal?

    STEP 2. Connector check: A-105 manifold absolute pressure sensor connector

    Q. Is the check result normal?

    STEP 3. Perform resistance measurement at A-105 manifold absolute pressure sensor connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 3 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-105 (terminal No. 3) manifold absolute pressure sensor connector and C-105 (terminal No. 31) engine-ECU connector.

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

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

  • Item 6: Manifold absolute pressure sensor
  • Q. Is the check result normal?

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

  • Item 6: Manifold absolute pressure sensor
  • Q. Is the check result normal?

    Author: admin