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P0155 on Toyota Tundra

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Factory diagnostic protocol and troubleshooting wire for fault code P0155 specifically for the Toyota Tundra (2022–2026, 3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP)).

Verified OEM Telemetry & Field Repair Tree
Toyota Tundra2022–2026
Toyota Tundra
Truck3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Tundra SAE Mode $01
ECU Network Bus
500 kbps CAN-FD
ISO 15765-4 Compliant
Drivability Status
Drivable (Short Trip)
Medium urgency level
Est. Repair Cost
$120 - $350 (DIY: $45 - $120)
Parts & Labor DIY
Check P0155 On Another Toyota Model:
Diagnose P0155 on Specific Tundra Model Year:

1. Symptoms of P0155 on Toyota Tundra

When the Engine Control Module (ECM/PCM) on your Toyota Tundra (3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP)) logs fault code P0155, drivers commonly observe:

Check Engine Light on immediately after cold start on Toyota Tundra (3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP))
Slightly increased cold-start emissions on Toyota Tundra (3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP))
No major driving performance issues once engine reaches full operating temperature on Toyota Tundra (3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP))
Toyota Tundra OBD-II Port Location
The 16-pin diagnostic connector is located Driver side lower dash assembly near parking brake. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Toyota Tundra

Historical warranty claims and technical repair bulletins for Toyota Tundra point to the following failure distribution:

55%
Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor (Toyota OEM Part)
25%
Blown O2 heater fuse in under-hood fuse block (Toyota OEM Part)
12%
Corroded or broken heater power/ground wiring (Toyota OEM Part)
8%
Faulty heater driver circuit in the PCM (Toyota OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for Toyota Tundra.

3. Step-by-Step DIY Repair Guide for Toyota Tundra

01
Check O2 Heater Fuse

Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on the Toyota Tundra equipped with 3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP).

Required Tool: Fuse Puller, Test Light
02
Test Heater Resistance on Bank 2 Sensor 1

Unplug the sensor connector and measure resistance between the two heater pins. An open circuit (infinite ohms / OL) confirms a dead internal heater. on the Toyota Tundra equipped with 3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP).

Required Tool: Digital Multimeter
03
Replace Bank 2 Upstream O2 Sensor

Remove faulty sensor and install a new OEM oxygen sensor with built-in heater. on the Toyota Tundra equipped with 3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP).

Required Tool: 22mm O2 Sensor Socket, Ratchet
04
Clear Codes and Perform Cold Start Verification

Clear DTCs and allow engine to cool down, then restart to confirm P0155 does not return. on the Toyota Tundra equipped with 3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP).

Required Tool: OBD-II Scanner
Recommended Parts & Testing Tools

Equipment for Diagnosing Toyota Tundra (P0155)

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Direct-Fit Replacement Part

Toyota Tundra OEM Replacement Sensor

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Direct-fit replacement assembly engineered to OEM tolerances for Toyota Tundra.

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Sensor Signal Voltage Meter

AstroAI Auto-Ranging Digital Multimeter

4.6 / 5.0 (Best Seller)

Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.

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BlueDriver Bluetooth Pro OBDII Scan Tool

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Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.

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Other Common Fault Codes on Toyota Tundra

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Toyota Tundra:

4. Toyota Tundra P0155 FAQs

What causes code P0155 to trigger on a Toyota Tundra?

On the Toyota Tundra (3.4L Twin-Turbo V6 (V35A-FTS 389HP) / i-FORCE MAX Hybrid (437HP)), P0155 is most frequently caused by Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor or Blown O2 heater fuse in under-hood fuse block.

Where is the OBD-II port located on my Toyota Tundra?

On the Toyota Tundra, the 16-pin DLC diagnostic connector is located Driver side lower dash assembly near parking brake. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Toyota Tundra with code P0155?

Yes. The sensor will take longer to warm up, causing brief open-loop fuel delay on cold starts. Given that P0155 carries a Medium severity rating, we advise avoiding heavy towing or aggressive throttle inputs until sensor readings are verified.