DTC P0038:00: Notes

DTC P0038:00	HO2S heater control circuit high input
DETECTION CONDITION	The PCM monitors the HO2S heater output voltage. If the PCM turns the HO2S heater off but the HO2S heater circuit voltage remains high the PCM determines that the HO2S heater circuit has a malfunction. Diagnostic support note  This is a continuous monitor (A/F sensor heater, 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 first drive cycle. FREEZE FRAME DATA (Mode 2)/Snapshot data is available. The DTC is stored in the PCM memory.
POSSIBLE CAUSE	HO2S connector or terminals malfunction HO2S heater malfunction PCM connector or terminals malfunction Short to power supply in wiring harness between HO2S terminal D and PCM terminal 2D PCM malfunction
Courtesy of MAZDA MOTORS CORP.

^*1 : Vehicles without advanced keyless entry and push button start system

^*2 : Vehicles with advanced keyless entry and push button start system