What does code P1186 mean?

Q: What does code P1186 mean?

O2 Sensor Heater Control Circuit Bank 1 Sensor 2. P1186 on BMW vehicles indicates that the engine control module has detected a fault in the heater circuit for the downstream oxygen sensor on bank 1, which is sensor 2 after the catalytic converter. The computer monitors the heater element's electrical current and expects a specific resistance range when the heater is commanded on, and this code sets when the measured current or voltage falls outside that expected window.

DTC codes / BMW codes / P1186

P1186 · BMWO2 Sensor Heater Control Circuit Bank 1 Sensor 2

P1186 on BMW vehicles indicates that the engine control module has detected a fault in the heater circuit for the downstream oxygen sensor on bank 1, which is sensor 2 after the catalytic converter. The computer monitors the heater element's electrical current and expects a specific resistance range when the heater is commanded on, and this code sets when the measured current or voltage falls outside that expected window.

SystemPowertrain

Code typeBMW specific

SeverityLow

Fix difficultyIntermediate

AreaFuel and air metering

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