2005 Dodge Grand Caravan P0032: Heater Control Circuit High Bank 1 Sensor 1 - O2 Sensor Replacement Not Resolving Issue
I recently encountered a check engine light with code P0032 — Heater Control Circuit High Bank 1 Sensor 1 on my 2005 Dodge Grand Caravan with a 3.8L engine. I was advised that the issue was caused by a faulty oxygen (O2) sensor located in front of the catalytic converter. I replaced it, and the check engine light disappeared for about a week. However, the same P0032 code has returned. When I tested the voltage to the sensor while the engine was running, it fluctuated between 9.5 and 10 volts — which is outside the normal range (typically around 0.1–0.9V for upstream O2 sensors). This suggests a problem with the wiring harness or signal path delivering power to the sensor. I’ve inspected the harness visually and don’t see any obvious breaks or damage. What should I do next? Is it possible that the replacement sensor is aftermarket, or could there be an issue with the vehicle’s wiring or ECU communication?
Did you purchase the O2 sensor from the dealership or is it an aftermarket unit?