Using WDS or equivalent

Connect the WDS or equivalent to the DLC-2.

Fig 1: Identifying DLC-2 Location
Courtesy of MAZDA MOTORS CORP.
Start the engine.
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. (See EGR VALVE REMOVAL/INSTALLATION )
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.)
Warm up the engine to normal operating temperature.
Place the vehicle on the chassis dynamometer.
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)
Verify that the EGR valve step number is 0 during idle.
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)
Stop the vehicle and verify that the EGR valve step number is 0 during idle.