EGR Valve: Testing and Inspection

EGR VALVE INSPECTION

EGR Control Inspection

Without using WDS or equivalent
1. Inspect the following:
- EGR pipe clogging
- PCM terminal voltage
- EGR valve signal
- Vehicle speed signal
- Throttle opening signal
- Engine coolant temperature signal

- EGR valve (If it is stuck or not moving smoothly, replace it with a new one.)

Using WDS or equivalent




1. Connect the WDS or equivalent to the DLC-2.
2. Start the engine.
3. Using the "SEGRP" simulation function, operate with Steps 0 (idling) to 52 and verify that the engine speed becomes unstable or the engine stalls.
- If the engine speed does not change, perform the following procedure:
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. Using the "SEGRP" simulation function, verify that it operates with Steps 0 (idling) to 52.
- If the EGR valve operates, inspect the following:
- EGR pipe clogging

- If the EGR valve does not operate, inspect the following:
- PCM terminal voltage
- EGR valve signal

- EGR valve (If it is stuck or not moving smoothly, replace it with a new one.)

4. Warm up the engine to normal operating temperature.
5. Place the vehicle on the chassis dynamometer.
6. Monitor the following signals using the PID/data monitor.
- EGR valve step number (SEGRP)
- Engine speed (RPM)
- Vehicle speed (VSS)
- Throttle position (TP)
- Engine coolant temperature (ECT)

7. Verify that the EGR valve step number is 0 during idle.
8. Verify that the EGR valve step number increases when the accelerator pedal is depressed to increase the vehicle speed.
- If it does not increase, inspect the following using the PID/data monitor.
- Vehicle speed (VSS)
- Throttle position (TP)
- Engine coolant temperature (ECT)

9. Stop the vehicle and verify that the EGR valve step number is 0 during idle.

On-vehicle Inspection
1. Verify that the buzzing sound (valve operation sound) is heard from the EGR valve when engine cranking.
- If the buzzing sound is not heard, perform the resistance inspection.

Resistance Inspection
1. Disconnect the EGR valve connector.







2. Measure the resistance between the EGR valve terminals.
- If within the specification, perform out the "Circuit Open/Short Inspection".
- If not within the specification, replace the EGR valve.

Circuit Open/Short Inspection




1. Disconnect the PCM connector.
2. Inspect the following wiring harnesses for open or short circuit (continuity check).

Open circuit
- If there is no continuity, there is an open circuit. Repair or replace the wiring harness.
- EGR valve terminal A and PCM terminal 2AR
- EGR valve terminal B and PCM terminal 2AY
- EGR valve terminal E and PCM terminal 2AU
- EGR valve terminal F and PCM terminal 2AV
- EGR valve terminal C and main relay terminal B
- EGR valve terminal D and main relay terminal B

Short circuit
- If there is continuity, there is a short circuit. Repair or replace the wiring harness.
- EGR valve terminal A and body GND
- EGR valve terminal B and body GND
- EGR valve terminal E and body GND
- EGR valve terminal F and body GND