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P0155BMWBMW X5 HubAll BMW P0155Medium Severity

P0155 on BMW X5

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Factory diagnostic protocol and troubleshooting wire for fault code P0155 specifically for the BMW X5 (2020–2026, 3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP)).

Verified OEM Telemetry & Field Repair Tree
BMW X52020–2026
BMW X5
SUV3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
X5 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 BMW Model:
Diagnose P0155 on Specific X5 Model Year:

1. Symptoms of P0155 on BMW X5

When the Engine Control Module (ECM/PCM) on your BMW X5 (3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP)) logs fault code P0155, drivers commonly observe:

Check Engine Light on immediately after cold start on BMW X5 (3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP))
Slightly increased cold-start emissions on BMW X5 (3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP))
No major driving performance issues once engine reaches full operating temperature on BMW X5 (3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP))
BMW X5 OBD-II Port Location
The 16-pin diagnostic connector is located Driver footwell beside brake pedal behind access door. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on BMW X5

Historical warranty claims and technical repair bulletins for BMW X5 point to the following failure distribution:

55%
Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor (BMW OEM Part)
25%
Blown O2 heater fuse in under-hood fuse block (BMW OEM Part)
12%
Corroded or broken heater power/ground wiring (BMW OEM Part)
8%
Faulty heater driver circuit in the PCM (BMW OEM Part)
* Source: Synthesized from NHTSA ODI field repair telemetry and verified OEM Technical Service Bulletin (TSB) repair tree frequency percentiles for BMW X5.

3. Step-by-Step DIY Repair Guide for BMW X5

01
Check O2 Heater Fuse

Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on the BMW X5 equipped with 3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP).

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 BMW X5 equipped with 3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP).

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 BMW X5 equipped with 3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP).

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 BMW X5 equipped with 3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP).

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

Equipment for Diagnosing BMW X5 (P0155)

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Direct-Fit Replacement Part

BMW X5 OEM Replacement Sensor

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Direct-fit replacement assembly engineered to OEM tolerances for BMW X5.

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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 BMW X5

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the BMW X5:

4. BMW X5 P0155 FAQs

What causes code P0155 to trigger on a BMW X5?

On the BMW X5 (3.0L Turbo I6 (375HP) / 4.4L V8 M60i / xDrive50e PHEV (483HP)), 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 BMW X5?

On the BMW X5, the 16-pin DLC diagnostic connector is located Driver footwell beside brake pedal behind access door. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my BMW X5 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.