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Home >> Mazda >> 2010 >> 5 Touring, 2.3 L >> Repair and Diagnosis >> Engine Performance >> System >> Symptom Troubleshooting [L3] - Engine >> Engine Control System Operation Inspection >> Fuel Injector Operation Inspection
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Fuel Injector Operation Inspection

If simulation function of M-MDS is used: 

SYMPTOM TROUBLESHOOTING CHART - FUEL INJECTOR OPERATION

STEP INSPECTION RESULTS ACTION
1 Start the engine and warm it up to normal operating temperature.
Access the INJ#1, INJ#2, INJ#3 and INJ#4 PIDs using the M-MDS.
Turn the fuel injector from on to off using the PIDs each cylinder.
Does the engine speed drop?
Yes Fuel injector work properly.
No Go to the next step.
2 Disconnect the fuel injector that the fuel injector operation sound does not heard at Step 1.
Turn the ignition switch to ON (engine off). Measure the voltage between suspect fuel injector connector terminal B (wiring harness-side) and body GND.
Is the voltage B+?
Yes Go to the next step.
No Repair or replace for open or short circuit between fuel injector connector terminal B and main relay terminal C.
3 Inspect for open or short circuit between suspect fuel injector terminal A and following PCM terminals: 
  • Fuel injector No. 1
    • PCM terminal 2BB
  • Fuel injector No. 2
    • PCM terminal 2BC
  • Fuel injector No. 3
    • PCM terminal 2BD
  • Fuel injector No. 4
    • PCM terminal 2AZ

Is there any open or short circuit detected?
Yes Repair or replace for open circuit.
No Go to the next step.
4 Inspect the fuel injector.
Is the fuel injector normal?
Yes Replace the PCM.
(See PCM REMOVAL/INSTALLATION .)
No Replace the fuel injector.
(See FUEL INJECTOR REMOVAL/INSTALLATION .)

If simulation function of M-MDS is not used: 

SYMPTOM TROUBLESHOOTING CHART - FUEL INJECTOR OPERATION (M-MDS NOT USED)

STEP INSPECTION RESULTS ACTION
1 While cranking the engine, inspect for fuel injector operation sound at each cylinder using a soundscope.
Is operation sound heard?
Yes Fuel injector work properly.
No Go to the next step.
2 Disconnect the fuel injector that the fuel injector operation sound does not heard at Step 1.
Turn the ignition switch to ON (engine off). Measure the voltage between suspect fuel injector connector terminal B (wiring harness-side) and body GND.
Is the voltage B+?
Yes Go to the next step.
No Repair or replace for open or short circuit between fuel injector connector terminal B and main relay terminal C.
3 Inspect for open or short circuit between suspect fuel injector terminal A and following PCM terminals: 
  • Fuel injector No. 1
    • PCM terminal 2BB
  • Fuel injector No. 2
    • PCM terminal 2BC
  • Fuel injector No. 3
    • PCM terminal 2BD
  • Fuel injector No. 4
    • PCM terminal 2AZ

Is there any open or short circuit detected?
Yes Repair or replace for open circuit.
No Go to the next step.
4 Inspect the fuel injector.
Is the fuel injector normal?
Yes Replace the PCM.
(See PCM REMOVAL/INSTALLATION .)
No Replace the fuel injector.
(See FUEL INJECTOR REMOVAL/INSTALLATION .)