DTC P0054-00: HO2S Heater Resistance: Notes

DTC DETECTION DESCRIPTION

DTC P0054:00	HO2S heater resistance
DETECTION CONDITION	The PCM monitors the HO2S heater resistance when under the HO2S heater control. If the resistance is more than 34 ohms, the PCM determines that there is a HO2S heater circuit problem. Diagnostic support note This is an intermittent monitor (A/F sensor heater, HO2S heater). The check engine light 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/Snapshot data is available. DTC is stored in the PCM memory.
FAIL-SAFE FUNCTION	Stops fuel feedback control of HO2S
POSSIBLE CAUSE	HO2S connector or terminals malfunction Short to ground or open circuit in HO2S heater power supply circuit Short to ground in wiring harness between ENGINE1 15 A fuse and HO2S terminal C ENGINE1 15 A fuse malfunction Open circuit in wiring harness between main relay terminal C and HO2S terminal C HO2S heater malfunction PCM connector or terminals malfunction Open circuit in wiring harness between HO2S terminal D and PCM terminal 2C Short to ground in wiring harness between HO2S terminal D and PCM terminal 2C PCM malfunction

Fig 1: PCM Wiring Harness-Side Connector Terminals

Courtesy of MAZDA MOTORS CORP.