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Home >> Mazda >> 2007 >> 3 Mazdaspeed, 2.3 L >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting (L3 With TC) >> Engine Control System Operation Inspection >> Fuel Injector Operation Inspection >> If simulation function of M-MDS is used:
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If simulation function of M-MDS is used:

OPERATION OF FUEL INJECTOR INSPECTION

STEP INSPECTION ACTION
1 Start the engine and warm it up until normal operating temperature. Connect the M-MDS to DLC-2.
Select the INJ#1, INJ#2, INJ#3, and INJ#4 PIDs.
Turn the fuel injector from on to off using the PIDs for each cylinder.
Does the engine speed drop?
Yes Fuel injector work properly
No Engine speed does not drop an any cylinder: 
Go to the next steps.
Engine speed drops on some cylinders: 
Go to step 3.
2 Perform the Main Relay Operation Inspection.
(See MAIN RELAY OPERATION INSPECTION ).
Does the main relay work properly?
Yes Go to the next step.
No Repair or replace the malfunctioning parts.
3 Inspect the fuel injector of the suspected cylinder.
Is the fuel injector normal?
Yes Inspect the following for the suspected cylinder.
  • Fuel injector power and/or ground systems related wiring harness and connectors.

If all items normal replace the PCM.
(See PCM REMOVAL/INSTALLATION .)
No Replace the fuel injector.
4 Perform KOER self-test function using the M-MDS.
(See KOEO/KOER SELF TEST .)
Are DTCs P0201, P0202, P0203 and/or P0204 present?
Yes Go to the appropriate DTC test.
(See DTC TABLE .)
No Go to the next step.
5 Inspect the fuel injector of the suspected cylinder.
Is the fuel injector normal?
Yes Inspect the following for the suspected cylinder:
  • PCM terminals (pulled-out pins, corrosion)
  • Injector driver module terminals (pulled-out pins, corrosion)
  • Fuel injector terminals (pulled-out pins, corrosion)

If all items are normal replace the PCM.
(See PCM REMOVAL/INSTALLATION .)
No Replace the fuel injector.