What does code P1155 mean on Toyota vehicles?
The heater circuit of the downstream air/fuel ratio sensor is malfunctioning.
OBD-II Code Toyota
P1155 — Toyota — Air/Fuel Ratio Sensor Heater Circuit (Bank 1 Sensor 2)
The heater circuit of the downstream air/fuel ratio sensor is malfunctioning.
Common symptoms
- Check engine light
Possible causes
- Heater circuit failure
- wiring issue
Initial recommendation
Check heater wiring and sensor resistance.
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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