DTC P0037: Notes

2008 Mazda 6 s Sport, 4D Hatchback, StandardSECTION Notes
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 P0037 DETECTION CONDITION AND POSSIBLE CAUSES

DTC P0037 Rear HO2S heater circuit low input
DETECTION CONDITION 
  • The PCM monitors the rear HO2S heater output voltage. If the PCM turns the rear HO2S heater on or off but the rear HO2S heater circuit voltage remains low the PCM determines that the rear HO2S heater circuit has a malfunction.

Diagnostic support note 
  • This is a continuous monitor (HO2S heater).
  • The 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.
  • DTCs are stored in the PCM memory.
POSSIBLE CAUSE 
  • Rear HO2S heater malfunction
  • Connector or terminal malfunction
  • Open circuit in the wiring harness between ignition switch and rear HO2S terminal C
  • Short to ground in the wiring harness between ignition switch and rear HO2S terminal C
  • Open circuit in the wiring harness between rear HO2S terminal D and PCM terminal 4Z
  • Short to ground in the wiring harness between rear HO2S terminal D and PCM terminal 4Z
  • PCM malfunction
G04324085Courtesy of MAZDA MOTORS CORP.
RENDER: 1.0x

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