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 intake pipe 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
  • 8 minutes or more have passed since the engine starting sequence was completed, when the engine coolant temperature at engine start is 0°C or lower.
  • Volumetric efficiency is higher than 20 %.
Judgement Criterion
  • Manifold absolute pressure sensor output voltage is less than 0.2 V (corresponding to a manifold absolute pressure of 5 kPa or less) for 2 seconds.

PROBABLE CAUSES



  • Failed manifold absolute pressure sensor
  • Open/short circuit 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-124 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-124 manifold absolute pressure sensor connector.

  • Use special tool test harness (MB991709) to connect connector, and measure at pick-up harness.
  • 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 9 .
Go to Step 4 .

STEP 4. Perform voltage measurement at B-29 engine-ECU connector.

  • Measure engine-ECU terminal voltage.
  • Ignition switch: ON
  • Voltage between terminal No. 44 and earth.
OK: 4.9 - 5.1 V

Q. Is the check result normal?
Go to Step 8 .
Go to Step 5 .

STEP 5. Connector check: B-29 engine-ECU connector

Q. Is the check result normal?
Go to Step 6 .
Repair or replace the connector.

STEP 6. Check harness between B-124 (terminal No. 3) manifold absolute pressure sensor connector and B-29 (terminal No. 44) engine-ECU connector.

  • Check power supply line for short circuit.

Q. Is the check result normal?
Go to Step 7 .
Repair the damaged harness wire.

STEP 7. 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 8. Connector check: B-29 engine-ECU connector

Q. Is the check result normal?

    Check and repair harness between B-124 (terminal No. 3) manifold absolute pressure sensor connector and B-29 (terminal No. 44) engine-ECU connector.

    • Check power supply line for open circuit and damage.
Repair or replace the connector.

STEP 9. Perform resistance measurement at B-124 manifold absolute pressure sensor connector.

  • Disconnect and measure at harness side.
  • Ignition switch: ON
  • Resistance between terminal No. 2 and earth.
OK: Continuity (2 Ω or less)

Q. Is the check result normal?
Go to Step 12 .
Go to Step 10 .

STEP 10. Connector check: B-29 engine-ECU connector

Q. Is the check result normal?
Go to Step 11 .
Repair or replace the connector.

STEP 11. Check harness between B-124 (terminal No. 2) manifold absolute pressure sensor connector and B-29 (terminal No. 46) engine-ECU connector.

  • Check earthing line for damage.

Q. Is the check result normal?
Go to Step 7 .
Repair the damaged harness wire.

STEP 12. Perform voltage measurement at B-124 manifold absolute pressure sensor connector.

  • Use special tool test harness (MB991709) to connect connector, and measure at pick-up harness.
  • Ignition switch: ON
  • Voltage between terminal No. 1 and earth.

    Altitude 0m: 3.8 - 4.2 V
    Altitude 600m: 3.5 - 3.9 V
    Altitude 1,200m: 3.3 - 3.7 V
    Altitude 1,800m: 3.0 - 3.4 V

Q. Is the check result normal?
Go to Step 15 .
Go to Step 13 .

STEP 13. Connector check: B-29 engine-ECU connector

Q. Is the check result normal?
Go to Step 14 .
Repair or replace the connector.

STEP 14. Check harness between B-124 (terminal No. 1) manifold absolute pressure sensor connector and B-29 (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 15. Perform voltage measurement at B-29 engine-ECU connector.

  • Measure engine-ECU terminal voltage.
  • Ignition switch: ON
  • Voltage between terminal No. 45 and earth.

    Altitude 0m: 3.8 - 4.2 V
    Altitude 600m: 3.5 - 3.9 V
    Altitude 1,200m: 3.3 - 3.7 V
    Altitude 1,800m: 3.0 - 3.4 V

Q. Is the check result normal?
Go to Step 17 .
Go to Step 16 .

STEP 16. Connector check: B-29 engine-ECU connector

Q. Is the check result normal?

    Check and repair check harness between B-124 (terminal No. 1) manifold absolute pressure sensor connector and B-29 (terminal No. 45) engine-ECU connector.

    • Check output line for open circuit and damage.
Repair or replace the connector.

STEP 17. Connector check: B-29 engine-ECU connector

Q. Is the check result normal?
Go to Step 7 .
Repair or replace the connector.