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Home >> Mazda >> 2007 >> 5 Touring, 2.3 L >> Repair and Diagnosis >> Engine Performance >> System >> On-Board Diagnostic [Engine Control System L3) >> DTC P0038 >> Notes
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DTC P0038: Notes

DTC P0038 DETECTION CONDITION AND POSSIBLE CAUSES

DTC P0038 Rear HO2S heater circuit high input
DETECTION CONDITION 
  • The PCM monitors the rear HO2S heater output voltage. If the PCM turns the rear HO2S heater off or on but the rear HO2S heater circuit remains high voltage, the PCM determines that the rear HO2S heater circuit has malfunction.
  • Diagnostic support note 

  • This is a continuous monitor (HO2S heater).
  • MIL illuminates if the PCM detects the above malfunction condition in two consecutive drive cycles or in one drive cycle while the DTC for the same malfunction has been stored in the PCM.
  • PENDING CODE is available if the PCM detects the above malfunction condition during the first drive cycle.
  • FREEZE FRAME DATA is available.
  • The DTC is stored in the PCM memory.
POSSIBLE CAUSE 
  • Short to power supply in wiring harness between rear HO2S terminal D and PCM terminal 2C
  • Short circuit in rear HO2S or PCM
  • Rear HO2S heater malfunction
  • PCM malfunction
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