O2 Sensor Heater Control Circuit High (Bank 1 Sensor 2)
The engine computer has found a problem in the heater circuit for the oxygen sensor after the catalytic converter on bank 1. The circuit is drawing the wrong voltage, usually because of a short, wiring damage, or a failed sensor. This can keep the sensor from heating up correctly and can affect emissions control.
The vehicle is usually drivable, but the problem can increase emissions and may affect fuel control on some vehicles. Fix it soon, and do not ignore any rough running or additional warning lights.
P0038 means the PCM/ECM detected a high voltage condition in the heater control circuit for HO2S Bank 1 Sensor 2, the downstream oxygen sensor located after the catalytic converter on bank 1. The heater circuit is monitored because the sensor needs to reach operating temperature quickly for accurate feedback. A high circuit reading usually points to a short to power, damaged wiring, corroded connector, blown fuse, or an internal sensor heater fault.
Bank 1 is the side of the engine with cylinder number 1. Sensor 2 is the oxygen sensor located after the catalytic converter on that bank.
Yes. A failed heater element inside the downstream oxygen sensor is one of the most common causes.
No. The code will usually return if the wiring or sensor problem is still present.
Not usually. This code points to the oxygen sensor heater circuit, not the catalytic converter itself.