LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2007 >> 3 L4-2.0L >> Repair and Diagnosis >> Powertrain Management >> Emission Control Systems >> Exhaust Gas Recirculation >> Testing and Inspection
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Exhaust Gas Recirculation: Testing and Inspection

EGR Control System Inspection
1. Crank the engine and verify that 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 DTC inspection.
(See DTC TABLE[LF, L3].) Diagnostic Trouble Code Descriptions

2. Start the engine and idle it.
3. Warm up the engine to normal operating temperature.
4. Access the following PIDs:
- ECT, RPM, SEGRP_DSD, APP1, APP2, VSS

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

- If the SEGRP_DSD value does not increase, inspect the VSS, APP1, APP2, TP and ECT PIDs. (See PCM INSPECTION[LF, L3].) Diagnostic Trouble Code Descriptions

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