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P0155GMCGMC Yukon HubAll GMC P0155Medium Severity

P0155 on GMC Yukon

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Factory diagnostic protocol and troubleshooting wire for fault code P0155 specifically for the GMC Yukon (2021–2026, 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax).

Verified OEM Telemetry & Field Repair Tree
GMC Yukon2021–2026
GMC Yukon
SUV5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Yukon 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 GMC Model:
Diagnose P0155 on Specific Yukon Model Year:

1. Symptoms of P0155 on GMC Yukon

When the Engine Control Module (ECM/PCM) on your GMC Yukon (5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax) logs fault code P0155, drivers commonly observe:

Check Engine Light on immediately after cold start on GMC Yukon (5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax)
Slightly increased cold-start emissions on GMC Yukon (5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax)
No major driving performance issues once engine reaches full operating temperature on GMC Yukon (5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax)
GMC Yukon OBD-II Port Location
The 16-pin diagnostic connector is located Driver side under steering column. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on GMC Yukon

Historical warranty claims and technical repair bulletins for GMC Yukon point to the following failure distribution:

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

3. Step-by-Step DIY Repair Guide for GMC Yukon

01
Check O2 Heater Fuse

Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on the GMC Yukon equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.

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 GMC Yukon equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.

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 GMC Yukon equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.

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 GMC Yukon equipped with 5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax.

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

Equipment for Diagnosing GMC Yukon (P0155)

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Direct-Fit Replacement Part

GMC Yukon OEM Replacement Sensor

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Direct-fit replacement assembly engineered to OEM tolerances for GMC Yukon.

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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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Top Mobile OBD-II Scanner

BlueDriver Bluetooth Pro OBDII Scan Tool

4.7 / 5.0 (50,000+ Reviews)

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

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Other Common Fault Codes on GMC Yukon

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the GMC Yukon:

4. GMC Yukon P0155 FAQs

What causes code P0155 to trigger on a GMC Yukon?

On the GMC Yukon (5.3L / 6.2L V8 (Denali Ultimate) / 3.0L Duramax), 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 GMC Yukon?

On the GMC Yukon, the 16-pin DLC diagnostic connector is located Driver side under steering column. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my GMC Yukon 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.