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Home >> Mazda >> 2012 >> 6 i Touring >> Repair and Diagnosis >> External Pages >> Different car >> Section 547 (Symptom Troubleshooting (Engine - L5)) >> Engine Control System Operation Inspection [L5] >> Fuel Injector Operation Inspection

Fuel Injector Operation Inspection

WARNING: This page is about a different car, the 2009 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

If simulation function of M-MDS is used: 

STEP INSPECTION RESULTS 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 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 engine speed does not drop at Step 1
Turn the ignition switch to ON position.
Measure the voltage between suspect fuel injector connector terminal A (wiring harness-side) and body GND
Is the voltage B+?
Yes Is the voltage B+?
No Repair or replace for open or short circuit between fuel injector connector terminal A and fuel pump relay connector terminal C.
3 Inspect for open or short circuit between suspect fuel injector terminal B 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
Yes Repair or replace for open or short circuit. Go to the next step.
No Go to the next step.
4 Inspect suspect fuel injector.
(See FUEL INJECTOR INSPECTION [L5] .)
Is the fuel injector normal?
Yes Replace the PCM
(See PCM REMOVAL/INSTALLATION [L5] .)
No Replace the fuel injector.
(See FUEL INJECTOR REMOVAL/INSTALLATION [L5] .)

If simulation function of M-MDS is used: 

STEP INSPECTION RESULTS ACTION
1 While cranking 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 position. Measure the voltage between suspect fuel injector connector terminal A (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 A and fuel pump relay connector terminal C
3 Inspect for open or short circuit between suspect fuel injector terminal B 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
Yes Repair or replace for open or short circuit.
No Go to the next step
4 Inspect suspect fuel injector
(See FUEL INJECTOR INSPECTION [L5] .)
Is the fuel injector normal?
Yes Replace the PCM.
(See PCM REMOVAL/INSTALLATION [L5] .)
No Replace the fuel injector
(See FUEL INJECTOR REMOVAL/INSTALLATION [L5] .)