O2 Sensor Heater Circuit Malfunction (Bank 1, Sensor 1)
Powertrain Code · Low
What does P0135 mean?
The heater circuit in the upstream O2 sensor on bank 1 has failed, delaying sensor warm-up.
System: O2 Sensor
P0135 is a powertrain diagnostic trouble code indicating o2 sensor heater circuit malfunction (bank 1, sensor 1). This code is classified as low severity, which means: minor issue — monitor and fix at convenience. We have vehicle-specific diagnostic data for 43 models below. Select your vehicle for tailored causes, symptoms, and repair cost estimates.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your vehicle.
See causes, symptoms, and repair costs for P0135 on specific vehicles: