Exhaust Gas Recirculation: Testing and Inspection

EGR Control System Inspection
If simulation function of M-MDS is used:
1. Crank the engine and verify that the EGR valve operation (initial operation) sound is heard.
- If the operation sound is not heard, connect the M-MDS to the DLC-2 and verify that the DTC P0403 is shown. Perform the DTC inspection. (See DTC TABLE[L3 WITH TC].) Diagnostic Trouble Code Descriptions

2. Start the engine run it is idling.
3. Increase the step value of the EGR valve from 0 to 40 using the SEGR PID of the simulation function.
4. Operate the EGR valve and inspect if the engine speed becomes unstable or the engine stalls.
- If the engine speed does not change, proceed to the following.
1. Stop the engine.
2. Remove the EGR valve.
3. Connect the EGR valve connector.
4. Turn the ignition switch to the ON position.
5. Increase the step value of EGR valve from 0 to 40 using SEGRP PID.
6. Verify that the EGR valve operates according to the SEGRP PID.
- If the EGR valve is operated, clean the EGR valve and the EGR gas passage.
- If the EGR valve does not operate, replace the EGR valve.

5. Start the engine and warm it up completely.
6. Access the following PIDs.
- ECT, RPM, SEGRP, APP1, APP2, TP_REL, VSS

7. Idle the vehicle and verify that the SEGRP value is 0.
8. Put the vehicle in drive.
9. Depress the accelerator pedal and verify that the SEGRP value increases.
- If the SEGRP value does not increase, inspect the VSS, TP and ECT PIDs. (See PCM INSPECTIONS WITH TC].)

10. Stop the vehicle and verify that the SEGRP value is returns to 0.

If simulation function of M-MDS is not used:
1. Verify that EGR valve operation (initial operation) sound is heard when the ignition switch is turned to the ON position.
- If the operation sound is not heard, connect the M-MDS to the DLC-2 and verify that the DTC P0403 is shown. Perform the DTC inspection. (See DTC TABLE[L3 WITH TC].) Diagnostic Trouble Code Descriptions
2. Start the engine and idle it.
3. Warm up the engine to normal operating temperature.
4. Select the following PIDs:
- ECT, RPM, SEGRP, APP1, APP2, TP_REL, VSS

5. Let the vehicle idle and verify that the SEGRP value is 0.
6. Put the vehicle in drive.
7. Depress the accelerator pedal and verify that the SEGRP value is increased.
- If the EGR valve increases, inspect the following:
- EGR valve (stuck open or closed)
- Wiring harness and connectors (Main relay - EGR valve - PCM)

- If the SEGRP value does not increase, inspect the VSS, APP1, APP2, TP_REL and ECT PIDs. (See PCM INSPECTIONS WITH TC].)

8. Stop the vehicle and verify that the SEGRP value returns to 0.