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DTC codes / P00xx · Fuel and air metering and auxiliary emission controls / P0064

P0064HO2S Heater Control Circuit High (Bank 2 Sensor 3)

P0064 indicates that the powertrain control module (PCM) has detected an abnormally high voltage on the heater control circuit for the downstream heated oxygen sensor (HO2S) on bank 2, which is the side of the engine that does not contain cylinder number one. The PCM commands the heater on to bring the sensor to operating temperature quickly, and it monitors the circuit for expected voltage behavior; a high-voltage condition tells the PCM that the circuit is likely open, shorted to voltage, or that the heater element inside the sensor has failed in a way that prevents current flow.

SystemPowertrain
Code typeGeneric (all makes)
SeverityLow
Fix difficultyIntermediate
AreaFuel and air metering and auxiliary emission controls

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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