Code No. P0108: Manifold Absolute Pressure Sensor Circuit High Input

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. 80) and earthed to the engine-ECU (terminal No. 73) from the manifold absolute pressure sensor (terminal No. 3).
The sensor signal is inputted to the engine-ECU (terminal No. 52) 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 JUDGMENT

Check Conditions

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

Judgment Criterion

The manifold absolute pressure sensor output voltage should exceed 4.72 V for 0.5 seconds.

PROBABLE CAUSES

Failed manifold absolute pressure sensor
Open circuit 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 06: 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: A-105 manifold absolute pressure sensor connector

Q. Is the check result normal?

Go to Step 3 .

Repair or replace the connector.

STEP 3. Perform resistance measurement at A-105 manifold absolute pressure sensor connector.

Disconnect and measure at harness side.
Ignition switch: ON
Resistance between terminal No. 3 and earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

Go to Step 7 .

Go to Step 4 .

STEP 4. Connector check: C-105 engine-ECU connector

Q. Is the check result normal?

Go to Step 5 .

Repair or replace the connector.

STEP 5. Check harness between A-105 (terminal No. 3) manifold absolute pressure sensor connector and C-105 (terminal No. 73) engine-ECU connector.

Check earthing line for open 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 06: 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. When the engine-ECU is replaced, write the chassis number (Refer to GROUP 00 - How to Perform Chassis Number Writing ). After replacing the engine-ECU, register the injector identification code and learn fuel injection (Refer to GROUP 00 - Precautions Before Service - What The Common Rail Engine Learns ).

STEP 7. M.U.T.-III data list

Refer to Data List Reference Table .

Item 06: 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 manifold absolute pressure sensor.