Code No. P0107: Manifold Absolute Pressure Sensor Circuit Low Input








OPERATION



  • A power voltage of 5 V is applied to the manifold absolute pressure sensor power terminal (terminal No. 3) from the engine-ECU (terminal No. 44) and earthed to the engine-ECU (terminal No. 46) from the manifold absolute pressure sensor (terminal No. 2).
  • The sensor signal is inputted to the engine-ECU (terminal No. 45) from the manifold absolute pressure sensor output terminal (terminal No. 1).

FUNCTION



  • The manifold absolute pressure sensor detects a change in inlet manifold pressure and inputs the signal to the engine-ECU.
  • In response to the signal, the engine-ECU corrects the fuel injection amount, etc.

TROUBLE JUDGMENT


Check Conditions
  • Engine is running.
  • More than 8 minutes have passed since the engine starting sequence was completed, when the engine coolant temperature at engine start is less than 0°C.
  • Volumetric efficiency is more than 20 %.
Judgement Criterion
  • Manifold absolute pressure sensor output voltage is less than 0.1 V (corresponding to an atmosphere pressure of 53 kPa or less) for 2 seconds.
FAIL-SAFE AND BACKUP FUNCTION
  • None.

PROBABLE CAUSES



  • Failed manifold absolute pressure sensor
  • Open/short circuit or harness damage in manifold absolute pressure sensor circuit or loose connector contact

  • Failed engine-ECU

DIAGNOSIS PROCEDURE

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

  • Refer to Data List Reference Table .

  1. Item 8: Manifold absolute pressure sensor

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Go to Step 2.

STEP 2. Connector check: B-12 manifold absolute pressure sensor connector

Q. Is the check result normal?
Go to Step 3.
Repair or replace the connector.

STEP 3. Perform voltage measurement at B-12 manifold absolute pressure sensor connector.

  • Disconnect connector, and measure at harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 3 and earth.
OK: 4.9 - 5.1 V

Q. Is the check result normal?
Go to Step 7.
Go to Step 4.

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

Q. Is the check result normal?
Go to Step 5.
Repair or replace the connector.

STEP 5. Check harness between B-12 (terminal No. 3) manifold absolute pressure sensor connector and B-08 (terminal No. 44) engine-ECU connector.

  • Check power supply line for open/short circuit.

Q. Is the check result normal?
Go to Step 6.
Repair the damaged harness wire.

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

  • Refer to Data List Reference Table .

  1. Item 8: Manifold absolute pressure sensor

Q. Is the check result normal?
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
Replace the engine-ECU.

STEP 7. Connector check: B-08 engine-ECU connector

Q. Is the check result normal?
Go to Step 8.
Repair or replace the connector.

STEP 8. Check harness between B-12 (terminal No. 3) manifold absolute pressure sensor connector and B-08 (terminal No. 44) engine-ECU connector.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 9.
Repair the damaged harness wire.

STEP 9. Perform voltage measurement at B-12 manifold absolute pressure sensor connector.

  • Use special tool test harness (MB991658) to connect connector, and measure at pick-up harness.
  • Ignition switch: ON
  • Voltage between terminal No. 1 and earth.

    Altitude 0 m: 1.2 - 1.8 V
    Altitude 600 m: 1.1 - 1.7 V
    Altitude 1,200 m: 1.0 - 1.6 V
    Altitude 1,800 m: 0.9 - 1.5 V

Q. Is the check result normal?
Go to Step 11.
Go to Step 10.

STEP 10. Check harness between B-12 (terminal No. 1) manifold absolute pressure sensor connector and B-08 (terminal No. 45) engine-ECU connector.

  • Check output line for short circuit.

Q. Is the check result normal?
Replace the manifold absolute pressure sensor.
Repair the damaged harness wire.

STEP 11. Perform voltage measurement at B-08 engine-ECU connector.

  • Disconnect engine-ECU harness, and connect special tool power plant ECU check harness (MB992110) to measure at connector for inspection.
  • Ignition switch: ON
  • Voltage between terminal No. 45 and earth.

    Altitude 0 m: 1.2 - 1.8 V
    Altitude 600 m: 1.1 - 1.7 V
    Altitude 1,200 m: 1.0 - 1.6 V
    Altitude 1,800 m: 0.9 - 1.5 V

Q. Is the check result normal?
Go to Step 6.

    Check and repair harness between B-12 (terminal No. 1) manifold absolute pressure sensor connector and B-08 (terminal No. 45) engine-ECU connector.

    • Check output line for open circuit and damage.