Diagnostic Procedure

DTC 71 EGR System Malfunction






WIRING DIAGRAM

DIAGNOSTIC PROCEDURE
1. CHECK VOLTAGE OF VACUUM SWITCHING VALVE (VSV FOR EGR) POWER SOURCE.
- If OK proceed to step 4.
- If not OK proceed to step 2.

2. CHECK RESISTANCE OF VSV FOR EGR.
- If OK proceed to step 3.
- If not OK replace VSV for EGR.

3. CHECK FOR OPEN AND SHORT IN HARNESS AND CONNECTOR BETWEEN EFI MAIN RELAY AND ECM.
- If OK check and replace ECM.
- If not OK repair or replace harness or connector.

4. CHECK EGR SYSTEM.
- If OK proceed to step 5.
- If not OK repair EGR system.

5. CHECK RESISTANCE OF EGR GAS TEMPERATURE SENSOR.
- If OK proceed to step 6.
- If not OK replace EGR gas temperature sensor.

6. CHECK FOR OPEN IN HARNESS AND CONNECTOR BETWEEN EGR GAS TEMPERATURE SENSOR AND ECM.
- If OK check and replace ECM.
- If not OK repair or replace harness or connector.