Inspection Procedure 36: High Pressure Fuel Regulator System








OPERATION



  • Power is supplied to the high pressure fuel regulator (terminal No. 1) from the engine-ECU (terminal No. 63, terminal No. 75 and terminal No. 87).
  • The engine-ECU (terminal No. 64) makes the power transistor in the unit be in "ON" position, and that makes currents go on the high pressure fuel regulator (terminal No. 1).

FUNCTION



  • The high pressure fuel regulator regulates the fuel pressure to keep the standard pressure by using the signal sent from the engine-ECU.

PROBABLE CAUSES



  • Failed high pressure fuel regulator
  • Open/short circuit or harness damage in high pressure fuel regulator circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE

STEP 1. Connector check: B-109 high pressure fuel regulator connector

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

STEP 2. Perform voltage measurement at B-109 high pressure fuel regulator connector.

  • Disconnect connector, and measure at the harness side.
  • Ignition switch: ON
  • Voltage between terminal No. 1 and earth.
OK: System voltage

Q. Is the check result normal?
Go to Step 6 .
Go to Step 3 .

STEP 3. Connector check: B-17 engine-ECU connector

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

STEP 4. Check harness between B-109 (terminal No. 1) high pressure fuel regulator connector and B-17 (terminal No. 63, terminal No. 75 and terminal No. 87) engine-ECU connector.

  • Check power supply line for open/short circuit.

Q. Is the check result normal?
Go to Step 5 .
Repair the damaged harness wire.

STEP 5. Check the trouble symptoms.

Q. Does trouble symptom persist?

Replace the engine-ECU.
Intermittent malfunction (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).

STEP 6. Connector check: B-17 engine-ECU connector

Q. Is the check result normal?
Go to Step 7 .
Repair or replace the connector.

STEP 7. Check harness between B-109 (terminal No. 2) high pressure fuel regulator connector and B-17 (terminal No. 64) engine-ECU connector.

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

Q. Is the check result normal?
Go to Step 8 .
Repair the damaged harness wire.

STEP 8. Check harness between B-109 (terminal No. 1) high pressure fuel regulator connector and B-17 (terminal No. 63, terminal No. 75 and terminal No. 87) engine-ECU connector.

  • Check power supply line for damage.

Q. Is the check result normal?
Go to Step 9 .
Repair the damaged harness wire.

STEP 9. Replace the high pressure fuel regulator assembly.

  • After replacing the high pressure fuel regulator, re-check the trouble symptoms.

Q. Does trouble symptom persist?

Replace the engine-ECU.
The check is end.