P1155 — Air/Fuel Ratio Sensor Heater Circuit (Bank 2 Sensor 1)
CAUTIONIs it safe to drive? Drive gently and get it looked at soon — it can worsen or fail inspection.
What P1155 means
This is a manufacturer-specific code — its meaning depends on the vehicle’s make (see below).
What P1155 means on specific makes
Toyota / Lexus / Scion CAUTION
Same fault as P1135 but on Bank 2 (the other cylinder bank on V6/V8 engines). The A/F sensor's heater circuit is out of spec, usually a burned-out internal heater element like a blown bulb filament.
- Failed Bank 2 upstream A/F sensor ($120-300)
- Blown A/F HEATER / EFI fuse (a short blows it)
- Open or corroded heater wiring
Check first: Check the dedicated A/F heater fuse first since a short there cuts power; then measure heater resistance at the Bank 2 sensor. Only appears on V-engines (4-cyl has no Bank 2).
Source: parts.olathetoyota.com/p1155-code, go-parts.com/garage/obd-p1155