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 from the engine-ECU connector terminal 5V&B/S5 and earthed to the engine-ECU connector terminal SENG from the manifold absolute pressure sensor earth terminal.
The sensor signal is inputted to the engine-ECU connector terminal B/S 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 JUDGEMENT

Check Condition

2 seconds later after the ignition switch has been in ON position or just after the engine has started up.

Judgement Criterion

Manifold absolute pressure sensor output voltage is more than 4.5 V (corresponding to a manifold absolute pressure of 114 kPa or more) 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 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 resistance measurement at manifold absolute pressure sensor connector.

Disconnect connector, and measure at harness side.
Resistance between terminal SENG line and earth.

OK: Continuity (2 Ω or less)

Q. Is the check result normal?

	Go to Step 5.

	Go to Step 3.

STEP 3. Check of open circuit, and damage in SENG line between manifold absolute pressure sensor connector and engine-ECU connector.

Q. Is the check result normal?

	Go to Step 4.

	Repair the connector(s) or wiring harness.

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. 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 6.

STEP 6. Replace the manifold absolute pressure sensor

After replacing the manifold absolute pressure sensor, erase the diagnosis code. Then, reconfirm whether the diagnosis code is stored.

Q. Is the diagnosis code stored?

	Replace the engine-ECU.

	Check end.