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HOMESERVICE MANUALSMAZDA20086 S SPORT, 4D HATCHBACK, STANDARDREPAIR AND DIAGNOSISEXTERNAL PAGESDIFFERENT CARSECTION 687 (ON-BOARD DIAGNOSTIC (ENGINE CONTROL SYSTEM L3) (2 OF 5))DTC P0044DIAGNOSTIC PROCEDURE
2008 Mazda 6 s Sport, 4D Hatchback, Standard

Diagnostic Procedure

2008 Mazda 6 s Sport, 4D Hatchback, StandardSECTION Diagnostic Procedure
WARNING: This page is about a different car, the 2007 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.
DTC P0044 DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 VERIFY FREEZE FRAME DATA AND DIAGNOSTIC MONITORING TEST RESULTS HAVE BEEN RECORDED 
  • Have FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS (HO2S heater related) been recorded?
 Yes Go to the next step.
No Record the FREEZE FRAME DATA and DIAGNOSTIC MONITORING TEST RESULTS on the repair order, then go to the next step.
2 VERIFY RELATED REPAIR INFORMATION AVAILABILITY 
  • Verify related Service Bulletins and/or on-line repair information availability.
  • Is any related repair information available?
 Yes Perform repair or diagnosis according to the available repair information.
  • If the vehicle is not repaired, go to the next step.
No Go to the next step.
3 INSPECT REAR HO2S CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch off.
  • Disconnect the rear HO2S connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, and corrosion).
  • Is there any malfunction?
 Yes Repair or replace the terminal, then go to Step 9.
No Go to the next step.
4 INSPECT REAR HO2S HEATER POWER CIRCUIT FOR OPEN CIRCUIT OR SHORT TO GND 
  • Turn the ignition switch to the ON position (Engine off).
  • Measure the voltage between rear HO2S terminal C (wiring harness-side) and body GND.
  • Is the voltage B+  ?
 Yes Go to the next step.
No Repair or replace the wiring harness for a possible open circuit or short to GND, then go to Step 9.
5 INSPECT REAR HO2S HEATER CONTROL CIRCUIT FOR SHORT TO GND 
  • Turn the ignition switch off.
  • Inspect for continuity between rear HO2S terminal D (wiring harness-side) and body GND.
  • Is there continuity?
 Yes Repair or replace the wiring harness for a possible short to GND, then go to Step 9.
No Go to the next step.
6 INSPECT REAR HO2S HEATER 
 Yes Replace the rear HO2S, then go to Step 9.
(See EXHAUST SYSTEM REMOVAL/INSTALLATION ).
No Go to the next step.
7 INSPECT PCM CONNECTOR FOR POOR CONNECTION 
  • Turn the ignition switch off.
  • Disconnect the PCM connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, and corrosion).
  • Is there any malfunction?
 Yes Repair or replace the terminal, then go to Step 9.
No Go to the next step.
8 INSPECT REAR HO2S HEATER CONTROL CIRCUIT FOR OPEN CIRCUIT 
  • Turn the ignition switch off.
  • Inspect for continuity between rear HO2S terminal D (wiring harness-side) and PCM terminal 2BE (wiring harness-side).
  • Is there continuity?
 Yes Go to the next step.
No Repair or replace the wiring harness for a possible open circuit, then go to the next step.
9 VERIFY TROUBLESHOOTING OF DTC P0044 COMPLETED 
  • Make sure to reconnect all disconnected connectors.
  • Clear the DTC from the PCM memory using the M-MDS or equivalent.
  • Perform the HO2S heater, HO2S, and TWC Repair Verification Drive Mode.

    (See OBD-II DRIVE MODE ).

  • Is the PENDING CODE for this DTC present?
 Yes Replace the PCM, then go to the next step.
(See PCM REMOVAL/INSTALLATION ).
No Go to the next step.
10 VERIFY AFTER REPAIR PROCEDURE 
 Yes Go to the applicable DTC inspection.
(See DTC TABLE ).
No DTC troubleshooting completed.
RENDER: 1.0x

NO RELATED

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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.