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

Control as if the inlet manifold vacuum pressure is 101 kPa.

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 .

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 .

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.