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P0036 Fault Code (Causes & Fixes) Heated Oxygen Sensor (HO2s) Control Circuit

Updated: Feb 4

✔ This article has been fact checked.

The "HO2S Heater Control Circuit - Bank 1 Sensor 2" OBD fault code P0036 is issued when the Engine Control Module (ECM) identifies a possible fault with the bank 1 secondary sensor or sensor 2 heater control circuit.

If a DTC is associated to the powertrain, an OBD scanner will read it as starting with P, thus the letter "P". Generic fault codes are those of the format P0xxx.

Table of Contents:

The Meaning of a P0036 Fault Code

The P0036 error code indicates that the heated oxygen sensor (HO2S) control circuit bank 1, sensor 2 is not transmitting the right data to the powertrain control module (PCM).

The engine exhaust should have a precise air-fuel ratio of 14.7 to 1 for the engine to function properly, and the HO2S (oxygen sensor) monitors the oxygen from the exhaust.

It's heated to guarantee the PCM maintains a fast reaction to the closed-loop system, lowering emissions during startup.