DTC P1498 EGR Solenoid Valve Signal #4 Circuit Malfunction (Low Input): Wiring Diagram

Fig 1: EGR Valve - Wiring Diagram

Courtesy of SUBARU OF AMERICA, INC.

DIAGNOSTIC PROCEDURE

Step	Check	Yes	No
1 CHECK POWER SUPPLY TO EGR VALVE.  Turn the ignition switch to OFF. Disconnect the connector from EGR valve. Turn the ignition switch to ON. Measure the voltage between EGR valve connector and engine ground. Connector & terminal  (E18) No. 2 (+) - Engine ground (-):  (E18) No. 5 (+) - Engine ground (-):	Is the voltage 10 V or more?	Go to step 2.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between EGR valve connector and main relay connector Poor contact of coupling connector
2 CHECK HARNESS BETWEEN ECM AND EGR VALVE CONNECTOR.  Turn the ignition switch to OFF. Disconnect the connector from ECM. Measure the resistance of harness between ECM and EGR valve connector. Connector & terminal  DTC P1492; (B134) No. 8 - (E18) No. 3:  DTC P1494; (B134) No. 9 - (E18) No. 1:  DTC P1496; (B134) No. 20 - (E18) No. 4:  DTC P1498; (B134) No. 30 - (E18) No. 6:	Is the resistance less than 1 Ω?	Go to step 3.	Repair the harness and connector. NOTE: In this case, repair the following item: Open circuit in harness between ECM and EGR valve connector Poor contact of coupling connector
3 CHECK HARNESS BETWEEN ECM AND EGR VALVE CONNECTOR.  Disconnect the connector from ECM. Measure the resistance between ECM and chassis ground. Connector & terminal  DTC P1492; (B134) No. 8 - Chassis ground:  DTC P1494; (B134) No. 9 - Chassis ground:  DTC P1496; (B134) No. 20 - Chassis ground:  DTC P1498; (B134) No. 30 - Chassis ground:	Is the resistance 1 MΩ or more?	Go to step 4.	Repair the ground short in harness between ECM and EGR valve connector.
4 CHECK FOR POOR CONTACT.  Check poor contact of ECM and EGR valve connectors.	Is there poor contact of ECM or EGR valve connector?	Repair the poor contact of ECM or EGR valve connector.	Replace the EGR valve. Ref. to EGR VALVE .