1.CHECK POWER SUPPLY TO EGR CONTROL VALVE. 1) Turn the ignition switch to OFF. 2) Disconnect the connector from the EGR control valve. 3) Turn the ignition switch to ON. 4) Measure the voltage between EGR control valve connector and engine ground. Connector & terminal (E18) No. 2 (+) — Engine ground (−): (E18) No. 5 (+) — Engine ground (−): | Is the voltage 10 V or more- | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P1498 COIL 4 EGR "A" CONTROL CIRCUIT LOW | Repair the harness and connector. NOTE: In this case, repair the following item: • Open circuit in harness between EGR control valve connector and main relay connector • Poor contact of coupling connector |
2.CHECK HARNESS BETWEEN ECM AND EGR CONTROL VALVE CONNECTOR. 1) Turn the ignition switch to OFF. 2) Disconnect the connector from ECM. 3) Measure the resistance of harness between ECM connector and EGR control valve connector. Connector & terminal DTC P1492; (E158) No. 12 — (E18) No. 3: DTC P1494; (E158) No. 48 — (E18) No. 1: DTC P1496; (E158) No. 25 — (E18) No. 4: DTC P1498; (E158) No. 49 — (E18) No. 6: | Is the resistance less than 1 -- | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P1498 COIL 4 EGR "A" CONTROL CIRCUIT LOW | Repair the harness and connector. NOTE: In this case, repair the following item: • Open circuit of harness between ECM connector and EGR control valve connector • Poor contact of coupling connector |
3.CHECK HARNESS BETWEEN ECM AND EGR CONTROL VALVE CONNECTOR. 1) Disconnect the connector from ECM. 2) Measure the resistance between ECM connector and chassis ground. Connector & terminal DTC P1492; (E158) No. 12 — Chassis ground: DTC P1494; (E158) No. 48 — Chassis ground: DTC P1496; (E158) No. 25 — Chassis ground: DTC P1498; (B134) No. 41 — Chassis ground: | Is the resistance 1 M- or more- | Diagnostic Procedure with Diagnostic Trouble Code (DTC) > DTC P1498 COIL 4 EGR "A" CONTROL CIRCUIT LOW | Repair ground short circuit of harness between ECM connector and EGR control valve connector. |
4.CHECK FOR POOR CONTACT. Check poor contact of ECM and EGR control valve connectors. | Is there poor contact in ECM or EGR control valve connector- | Repair the poor contact of ECM or EGR control valve connector. | Replace EGR control valve. EGR Control Valve |