What does code P1155 mean on BMW vehicles?
The heater circuit of the downstream oxygen sensor on bank 2 operates intermittently, affecting catalyst monitoring.
OBD-II Code BMW
P1155 — BMW — Oxygen Sensor Heater Circuit Intermittent (Bank 2 Sensor 2)
The heater circuit of the downstream oxygen sensor on bank 2 operates intermittently, affecting catalyst monitoring.
Common symptoms
- Reduced catalytic converter efficiency
Possible causes
- Aging oxygen sensor
- intermittent internal heater fault
Initial recommendation
Inspect downstream oxygen sensor heater operation and replace sensor if intermittent condition persists.
Safety notice
This information is for guidance only. Brand-specific codes may vary by model, year, engine, transmission and vehicle configuration. It does not replace a physical inspection or diagnosis by a qualified mechanic. If the vehicle is unsafe to operate, avoid driving it and seek professional inspection.
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