Detection Condition

• DTC P0135 indicates HO2S11 heater circuit (front right V6 or front 4-cylinder) is open, shorted to ground, shorted to VPWR or has low or high current draw.
• DTC P0141 indicates HO2S12 heater circuit (rear) is open, shorted to ground, shorted to VPWR or has low or high current draw.
• DTC P0155 indicates HO2S21 heater circuit (front left) is open, shorted to ground, shorted to VPWR or has low or high current draw.

HO2S heater heats HO2S sensor to temperatures of 1400°F (760°C). VPWR circuit supplies voltage to heater with PCM completing the ground when proper conditions are present.