Exhaust Gas Recirculation: Testing and Inspection
EGR CONTROL INSPECTION1. Turn the ignition switch to ON and verify that the EGR valve operation sound (initialization sound) is heard.
2. If the operation sound is not heard due to electrical failure, DTC will be displayed. If either DTC P1496, P1497, P1498, or P1499 presents, carry out inspection according to the code displayed.
3. Connect the SSTs (NGS) to the data link connector-2.
4. Start the engine and let it idle.
5. Select the SIMULATION TEST function on the NGS display.
6. Increase the EGR valve steps from 0 to 40 by selecting "SEGRP" and verify that the engine idle speed becomes unstable or the engine stalls.
7. If the engine condition will not change, do as follows.
(1) Stop the engine.
(2) Remove the EGR valve.
(3) With the EGR valve connector connected, turn the ignition switch to ON.
(4) Select the SIMULATION TEST function on the NGS display.
(5) Increase the EGR valve steps from 0 to 40 by selecting "SEGRP" and visually check that the EGR valve opens.
(6) It the valve opens, clean the EGR valve by using parts cleaner, reinstall the EGR valve, and repeat from (2).
(7) If the valve does not open, replace the EGR valve and repeat from (2).
8. Warm up the engine.
9. Place the vehicle on a chassis roller so that driving wheels can be rotated.
10. Start the vehicle and let it idle.
11. Select the PD/DATA MONITOR AND RECORD on the NGS display.
12. Select the following parameters.
- SEGRP (EGR valve steps)
- RPM (engine speed)
- VS (vehicle speed)
- TPS V (throttle position sensor voltage)
- ECT V (engine coolant temperature sensor voltage)
13. Verity that "SEGRP" is 0 while the vehicle is idling.
14. Depress the accelerator pedal and verify that the value increases.
15. If not, verify that:
(1) TPS V increases when the accelerator pedal is depressed.
(2) VSP increases while the tires are rotated.
(3) ECT V after warm up is within the reference.
16. If any of the above is not satisfied, check for continuity between the sensors and the PCM, check ground, and inspect the sensors as necessary.
17. Release the accelerator pedal.
18. Verify that SEGRP returns to 0 when the vehicle (wheels) is stopped.