P0155 on 2004-2010 Toyota Sienna — O2 Sensor Heater Circuit (Bank 2, Sensor 1)
1 vehicles · 1 makes · $220-$2,200 repair
Most Reported On
P0155 is an OBD-II diagnostic trouble code meaning “O2 Sensor Heater Circuit (Bank 2, Sensor 1).” The PCM has tested the heater circuit of the Bank 2, Sensor 1 upstream O2 sensor and detected a malfunction. The heater brings the sensor to operating temperature for closed-loop control. Indicates a heater element or circuit fault. This code is most commonly reported on 2004-2010 Toyota Sienna, with repair costs ranging from $220 to $2,200.
Common Causes
Typical Repair Cost
Based on 1 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
This is a powertrain code, so a basic OBD-II reader can read it. These read P0155.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple code reader for engine (P) codes on many compatible OBD-II vehicles. It does not support every vehicle or hybrid/EV application, and it does NOT read body, chassis or network codes; confirm exact-vehicle compatibility before buying.
- Read & clear engine (P) codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth scanner with a companion app that reads beyond the engine module — ABS, SRS and transmission — plus manufacturer-specific codes on many vehicles.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X V3.0 Elite OBD-II Scanner
by LAUNCH
Handheld scanner covering the four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level tablet with all-system coverage and bi-directional control, so you can command a module rather than only read it.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
What you can do yourself, and what needs a shop
Reading the code, clearing it, and watching whether it returns is a driveway job with the right scanner. These steps are not:
- Module programming or software updates — needs the manufacturer software or a J2534 pass-through with a paid subscription.
- Replacing a control module — most are VIN-programmed and immobilizer-registered, so a new one does nothing until it is coded to your car.
- Airbag/SRS component work — a stored fault can deploy a live device.
If the vehicle is still under warranty, check for an open recall or technical service bulletin before buying anything — the repair may already be covered.
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FAQ
What does P0155 mean?
P0155 stands for "O2 Sensor Heater Circuit (Bank 2, Sensor 1)." The PCM has tested the heater circuit of the Bank 2, Sensor 1 upstream O2 sensor and detected a malfunction. The heater brings the sensor to operating temperature for closed-loop control. Indicates a heater element or circuit fault.
What are the most common causes of P0155?
The most common causes of P0155 are: Failed O2 sensor heater element, Open or shorted heater wiring, Blown heater fuse, Corroded connector, Poor heater power/ground. The specific cause varies by vehicle.
How much does it cost to fix P0155?
Repair costs for P0155 range from $220 to $2,200, depending on the vehicle and root cause.
Which vehicles are affected by P0155?
Au7o has documented P0155 across 1 vehicle models from 1 manufacturers: Toyota.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.