Inspection Procedure 22: EGR Cooler Solenoid Valve System










OPERATION



  • Power is supplied to the EGR cooler solenoid valve (terminal No. 1) from the engine-ECU (terminal No. 63, terminal No. 75 and terminal No. 87).
  • The engine-ECU (terminal No. 52) makes the power transistor in the unit be in "ON" position, and that makes currents go on the EGR cooler solenoid valve (terminal No. 2).

FUNCTION



  • In response to a signal from the engine-ECU, the EGR cooler solenoid valve controls the operation of the exhaust flap.

PROBABLE CAUSES



  • Failed EGR cooler solenoid valve
  • Open/short circuit or harness damage in EGR cooler solenoid valve circuit or loose connector contact
  • Failed engine-ECU

DIAGNOSIS PROCEDURE


STEP 1. Connector check: B-111 EGR cooler solenoid valve connector


Q. Is the check result normal?

Go to Step 2 .
Repair or replace the connector.

STEP 2. Perform voltage measurement at B-111 EGR cooler solenoid valve 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-111 (terminal No. 1) EGR cooler solenoid valve 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-111 (terminal No. 1) EGR cooler solenoid valve 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 8 .
Repair the damaged harness wire.

STEP 8. Check harness between B-111 (terminal No. 2) EGR cooler solenoid valve connector and B-17 (terminal No. 52) engine-ECU connector.



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

Q. Is the check result normal?

Go to Step 9 .
Repair the damaged harness wire.

STEP 9. Replace the EGR cooler solenoid valve.



  • After replacing the EGR cooler solenoid valve, re-check the trouble symptoms.

Q. Does trouble symptom persist?

Replace the engine-ECU.
The check is end.