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 from the engine-ECU connector terminal MAP5 and earthed to the engine-ECU connector terminal MAPE from the manifold absolute pressure sensor connector terminal.
The sensor signal is inputted to the engine-ECU connector terminal MAP from the manifold absolute pressure sensor output terminal.

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 coolant temperature is more than 0°C at the engine starts.
Volumetric efficiency is more than 20 %.

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 0.2 V (corresponding to a manifold absolute pressure of 5 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

Data list reference table (Refer to ).

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. Perform voltage measurement at manifold absolute pressure sensor connector.

Disconnect connector, and measure at harness side.
Ignition switch: "ON"
Voltage between terminal engine-ECU MAP5 line and body earth.

OK: 4.9 - 5.1 V

Q. Is the check result normal?

	Go to Step 5.

	Go to Step 3.

STEP 3. Check harness between manifold absolute pressure sensor connector terminal and engine-ECU connector terminal MAP5.

Check power supply line for open/short circuit.

Q. Is the check result normal?

	Go to Step 4.

	Repair or replace the connector, or repair the damaged harness wire.

STEP 4. M.U.T.-III data list

Data list reference table (Refer to ).

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 5. Check harness between manifold absolute pressure sensor connector terminal and engine-ECU connector terminal MAP5.

Check power supply line for damage.

Q. Is the check result normal?

	Go to Step 6.

	Repair or replace the connector, or repair the damaged harness wire.

STEP 6. Perform voltage measurement at 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 engine-ECU MAP line and body earth.

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

Q. Is the check result normal?

	Go to Step 8.

	Go to Step 7.

STEP 7. Check harness between manifold absolute pressure sensor connector terminal and engine-ECU connector terminal MAP.

Check output line for short circuit.

Q. Is the check result normal?

	Replace the manifold absolute pressure sensor.

	Repair or replace the connector, or repair the damaged harness wire.

STEP 8. Perform voltage measurement at 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 MAP and body earth.

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

Q. Is the check result normal?

	Go to Step 4.

	Repair or replace the connector, or check and repair harness between manifold absolute pressure sensor connector terminal and engine-ECU connector terminal MAP. Check output line for open circuit and damage.