LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Mazda >> 2007 >> 3 Mazdaspeed, 2.3 L >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting (L3 With TC) >> Engine Control System Operation Inspection >> If simulation function of M-MDS is not used: >> Overview
April 5, 2026: LEMON Manuals is launched! Read the announcement.

If simulation function of M-MDS is not used:: Overview

  1. Perform the fuel pump operation inspection.
  2. Verify that fuel pump relay operation sound is heard, while cranking the engine.
    • If the operation sound is not heard, inspect the following:
      • Fuel pump relay
      • Wiring harnesses and connectors (Main relay-fuel pump relay-PCM terminal 4Q)
  3. Remove the fuel-filler cap.
  4. Verify that the fuel pump unit operation sound frequency at cranking is higher than during idle.
    • If it cannot verified, inspect for the following:
      • Fuel pump resister
      • Fuel pump relay
      • Wiring harnesses and connectors (open circuit at fuel pump relay terminal C-fuel pump terminal B)


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


  1. Start the engine.
  2. Disconnect the vacuum hose between the purge solenoid valve and the charcoal canister.
  3. Put a finger to the purge solenoid valve and verify that there is no vacuum applied when the engine is cold.
    • If there is vacuum, inspect the following:
      • Wiring harness and connectors (Purge solenoid valve-PCM terminal, 2AB)
      • Purge solenoid valve
  4. Warm up the engine to the normal operating temperature.
  5. Stop the engine.
  6. Connect the M-MDS to the DLC-2 and verify that the DTC P0443 is shown. Perform DTC inspection. (See DTC TABLE .)
  7. Turn the ignition switch to the ON position.
  8. Select the ECT PID.
  9. Verify that the engine coolant temperature is above 60°C {140°F}  .
    • If the M-MDS indicates that the temperature is below 60°C {140°F}  , perform the ECT sensor inspection.
  10. Set the vehicle on the dynamometer or chassis roller.
    WARNING:
    • When the dynamometer or chassis roller is operating, there is a possibility that the operator may come into contact with or be caught up in the rotating parts, leading to serious injuries or death. When performing work while the dynamometer or chassis roller is operating, be careful not to contact or be caught up in any of the rotating parts.
  11. Drive vehicle at an engine speed to approx. 2000 rpm  for 30 s or more. 
  12. Put a finger to the purge solenoid valve and verify that there is no vacuum applied during Step  2.
    • If there is no vacuum, inspect the following:
      • Wiring harness and connector (Main relay - purge solenoid valve - PCM terminal 2AB)
      • Purge solenoid valve
      • MAF, APP1, APP2, TP_REL and LOAD PIDs
    • If there is vacuum, inspect the following:
      • Vacuum hose (Purge solenoid valve - charcoal canister)


  1. Start the engine and run it is idling.
  2. Disconnect the hose between the wastegate control solenoid valve and the intake pipe.
  3. Put a finger to the wastegate control solenoid valve and verify that there is no pressure applied.
    • If there is pressure, inspect the following:
      • Wiring harness and connectors (Wastegate control solenoid valve - PCM terminal 2AA)
      • Wastegate control solenoid valve (Stuck open)
  4. Warm up the engine to normal operating temperature.
  5. Connect the M-MDS to the DLC-2 and verify that the DTC P0245 or P0246 are shown. Perform the DTC inspection.

    (See DTC P0245 .)

    (See DTC P0246 .)

  6. Warm up the engine to normal operating temperature.
  7. Monitor the VGT and APP PIDs using the M-MDS.
  8. The hose between the wastegate control solenoid valve and intake pipe is disconnected.
  9. Run the engine with the APP PID above 30% and verify that the VGT PID value increases from 0% and there is pressure applied.
    • If the VGT PID is 0%  , inspect the TP_REL PID.
    • If there is no pressure applied, inspect for the following:
      • Wastegate control solenoid valve (Stuck closed)
      • Hose connection (Intake hose (turbocharger compressor downstream side) - wastegate actuator - intake hose (turbocharger compressor upstream side)
scientia non olet · About LEMON Manuals