Inspection Procedure 27: Engine Oil Pressure Switch System








OPERATION



  • The battery voltage is applied to the engine oil pressure switch (terminal No. 1) from the engine-ECU (terminal No. 55).

FUNCTION



  • When the oil pressure switch is in ON position, the signal meaning the engine oil pressure switch is input into the engine-ECU. The engine-ECU controls the oil pressure warning lamp based on this signal.

PROBABLE CAUSES



  • Failed engine oil pressure switch
  • Open/short circuit or harness damage in engine oil pressure switch circuit or loose connector contact
  • Lack of oil pressure
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-17 engine-ECU connector

Q. Is the check result normal?
Go to Step 2 .
Repair or replace the connector.

STEP 2. Connector check: B-21 oil pressure switch connector

Q. Is the check result normal?
Go to Step 3 .
Repair the connector.

STEP 3. Check harness between B-21 (terminal No. 1) engine oil pressure switch connector and B-17 (terminal No. 55) engine-ECU connector.

  • Check output line for open/short circuit and damage.

Q. Is the check result normal?
Go to Step 4 .
Repair.

STEP 4. Oil pressure check

  • Oil pressure check (Refer to GROUP 12 - On-vehicle Service - Oil Pressure Check ).

Q. Is the check result normal?
Go to Step 5 .
Repair the oil pressure.

STEP 5. Check the engine oil pressure switch

  • Check the engine oil pressure switch (Refer to GROUP 12 - On-vehicle Service - Engine Oil Pressure Switch ).

Q. Is the check result normal?
Replace the engine-ECU.
Replace the engine oil pressure switch.