2007 Mazda 6 MazdaspeedFACTORY OEM SERVICE PROCEDURE

Fuel Injector Operation Inspection

If simulation function of M-MDS is used: 

FUEL INJECTOR OPERATION 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.
(See FUEL INJECTOR INSPECTION ).
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 injector driver module. (See INJECTOR DRIVER MODULE REMOVAL/INSTALLATION ).
No Replace the fuel injector.
(See FUEL INJECTOR REMOVAL/INSTALLATION ).
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.
(See FUEL INJECTOR INSPECTION ).
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 injector driver module.
(See INJECTOR DRIVER MODULE REMOVAL/INSTALLATION ).
No Replace the fuel injector.
(See FUEL INJECTOR REMOVAL/INSTALLATION ).

If simulation function of M-MDS is not used: 

FUEL INJECTOR OPERATION INSPECTION

STEP INSPECTION ACTION
1 Perform the KOER self-test function using the M-MDS.
(See (0102) KOEO/KOER SELF-TEST).
Are DTCs P0201, P0202, P0203 and/or P0204 present?		 Yes Go to appropriate DTC test.
(See DTC TABLE ).
No Go to the next step.
2 Inspect the fuel injector for each cylinder.
(See FUEL INJECTOR INSPECTION ).
Is the fuel injector normal?		 Yes Go to the next step.
No Replace the fuel injector.
(See FUEL INJECTOR REMOVAL/INSTALLATION ).
3 Inspect the following for the suspected cylinder:
  • Fuel injector power and/or ground system related wiring harnesses and connectors.
  • PCM terminals (pulled-out pins, corrosion)
  • Injector driver module terminals (pulled-out pins, corrosion)
  • Fuel injector terminals (pulled-out pins, corrosion)

Are all items normal?		 Yes Replace the injector driver module.
(See INJECTOR DRIVER MODULE REMOVAL/INSTALLATION ).
No Repair or replace malfunctioning parts.
Factory Service Tools

Use the Manual With the Right Hardware

Pair factory procedures with proven DIY tools so the instructions are easier to execute.

Disclosure: Verified tool recommendations may earn an affiliate commission at no cost to you.

Shop Manual-Ready ToolsCompare Repair QuoteQuote Shield Pro

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

  • • You smell fuel, burning insulation, or see smoke.
  • • Brakes feel soft, pull hard to one side, or make grinding noises.
  • • The engine overheats, stalls repeatedly, or misfires under load.
  • • You are missing required tools, torque specs, or safe lifting equipment.
  • • You are not confident in the next step or safety outcome.

Rather have a pro handle this?

A certified mobile mechanic comes to your home or office. They bring the tools, you stay comfortable. No tow truck, no waiting room, no surprises.

Comes to youSame-day available12-month warranty
Get a Free Quote

No obligation. See pricing before you book.