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. 2) from the engine-ECU (terminal No. 44) and earthed to the engine-ECU (terminal No. 46) from the manifold absolute pressure sensor (terminal No. 4).
  • 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 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 ).

  1. 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-14 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 B-14 manifold absolute pressure sensor connector.

  • Disconnect connector, and measure at harness side.
  • Resistance between terminal No. 4 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: B-26 engine-ECU connector

Q. Is the check result normal?
Go to Step 5 .
Repair or replace the connector.

STEP 5. Check harness between B-14 (terminal No. 4) manifold absolute pressure sensor connector and B-26 (terminal No. 46) engine-ECU connector.

  • Check earthing line for open circuit and damage.

Q. Is the check result normal?
Go to Step 6 .
Repair the damaged harness wire.

STEP 6. M.U.T.-III data list

  • Data list reference table (Refer to ).

  1. 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. M.U.T.-III data list

  • Data list reference table (Refer to ).

  1. 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 8 .

STEP 8. Replace the manifold absolute pressure sensor

  • After replacing the manifold absolute pressure sensor, reconfirm whether the diagnosis code is set.

Q. Is the diagnosis code set?
Replace the engine-ECU.
Check end.