Posted in Mitsubishi Colt

P0110 – Intake Air Temperature Sensor System MMC Colt

 Posted by  Posted on September 26, 2020

OPERATION

  • A power voltage of 5 V is applied to the intake air temperature sensor output terminal (terminal No. 3) of the manifold absolute pressure sensor connector from the engine-ECU (terminal No. 56).
  • The power voltage is earthed to the engine-ECU (terminal No. 33) from the manifold absolute pressure sensor (terminal No. 4).

    • FUNCTION

  • The intake air temperature sensor converts the intake air temperature into a voltage and inputs the voltage signal to the engine-ECU.
  • In response to the signal, the engine-ECU corrects the fuel injection amount, etc.
  • The intake air temperature sensor is a kind of resistor, which has characteristics to reduce its resistance as the intake air temperature rises. Therefore, the sensor output voltage varies with the intake air temperature, and becomes lower as the intake air temperature rises.

    • TROUBLE JUDGMENT

  • 2 seconds later after the ignition switch has been in “ON” position or the engine has started up.
  • The battery voltage is 8 V or more.
  • The sensor output voltage is 4.6 V or more (intake air temperature of below -45°C or equivalent) for 4 seconds.
  • The sensor output voltage is 0.1 V or less (intake air temperature of above 125°C or equivalent) for 4 seconds.

    • PROBABLE CAUSES

  • Failed intake air temperature sensor
  • Open or shorted intake air temperature sensor circuit, harness damage, or connector damage
  • Failed engine-ECU

    • DIAGNOSIS PROCEDURE

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

  • Item No. 6: Intake air temperature sensor

    • Q. Is the check result normal?

    STEP 2. Connector check: A-119 manifold absolute pressure sensor connector

    Q. Is the check result normal?

    STEP 3. Check intake air temperature sensor itself.

    Q. Is the check result normal?

    STEP 4. Perform resistance measurement at A-119 manifold absolute pressure sensor connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 4 and earth.

    • Q. Is the check result normal?

    STEP 5. Connector check: A-08 engine-ECU connector

    Q. Is the check result normal?

    STEP 6. Check harness between A-119 (terminal No. 4) manifold absolute pressure sensor connector and A-08 (terminal No. 33) engine-ECU connector.

  • Check earthing line for open circuit and damage.

    • Q. Is the check result normal?

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

  • Item No. 6: Intake air temperature sensor

    • Q. Is the check result normal?

    STEP 8. Perform voltage measurement at A-119 manifold absolute pressure sensor connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 3 and earth.

    • Q. Is the check result normal?

    STEP 9. Perform voltage measurement at A-08 engine-ECU connector.

  • Disconnect engine-ECU connector, and connect special tool power plant ECU check harness (MB991987), and then measure the voltage on the check connector.
  • Disconnect A-119 manifold absolute pressure sensor connector.
  • Ignition switch: ON
  • Voltage between terminal No. 56 and earth.

    • Q. Is the check result normal?

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

    Q. Is the check result normal?

  • Check output line for open circuit.

    • STEP 11. Connector check: A-08 engine-ECU connector

    Q. Is the check result normal?

    STEP 12. Check harness between A-119 (terminal No. 3) manifold absolute pressure sensor connector and A-08 (terminal No. 56) engine-ECU connector.

  • Check output line for short circuit.

    • Q. Is the check result normal?

    STEP 13. Perform voltage measurement at A-119 manifold absolute pressure sensor connector.

  • Use special tool test harness (MB991348) to connect only terminal No. 3 and No. 4, and then measure at pick-up harness.
  • Ignition switch: ON
  • Voltage between terminal No. 3 and earth.

    • Q. Is the check result normal?

    STEP 14. Connector check: A-08 engine-ECU connector

    Q. Is the check result normal?

    STEP 15. Check harness between A-119 (terminal No. 3) manifold absolute pressure sensor connector and A-08 (terminal No. 56) engine-ECU connector.

  • Check output line for damage.

    • Q. Is the check result normal?

    Author: admin