P0107 – Manifold Absolute Pressure Sensor Circuit Low Input MMC L200 IV

admin September 28, 2020

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 is lower than 0.28 V for 0.5 seconds.

PROBABLE CAUSES

Failed manifold absolute pressure sensor

Open/short or harness damage 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 voltage measurement at A-105 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.

Q. Is the check result normal?

STEP 4. Perform voltage measurement at C-105 engine-ECU connector.

Measure engine-ECU terminal voltage.

Ignition switch: ON

Voltage between terminal No. 72 and earth.

Q. Is the check result normal?

STEP 5. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

STEP 6. Check harness between A-105 (terminal No. 1) manifold absolute pressure sensor connector and C-105 (terminal No. 72) engine-ECU connector.

Check power supply line for short circuit.

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?

STEP 8. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

Check power supply line for open circuit and damage.

STEP 9. 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 10. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

STEP 11. 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 damage.

Q. Is the check result normal?

STEP 12. Perform voltage measurement at A-105 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. 2 and earth.

Q. Is the check result normal?

STEP 13. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

STEP 14. Check harness between A-105 (terminal No. 2) manifold absolute pressure sensor connector and C-105 (terminal No. 37) engine-ECU connector.

Check output line for short circuit.

Q. Is the check result normal?

STEP 15. Perform voltage measurement at C-105 engine-ECU connector.

Measure engine-ECU terminal voltage.

Ignition switch: ON

Voltage between terminal No. 37 and earth.

Q. Is the check result normal?

STEP 16. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

Check output line for open circuit and damage.

STEP 17. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

Author: admin