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P0155AudiAudi e-tron HubAll Audi P0155Medium Severity

P0155 on Audi e-tron

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Factory diagnostic protocol and troubleshooting wire for fault code P0155 specifically for the Audi e-tron (2020–2026, Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP)).

Verified OEM Telemetry & Field Repair Tree
Audi e-tron2020–2026
Audi e-tron
EVDual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
e-tron 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 Audi Model:
Diagnose P0155 on Specific e-tron Model Year:

1. Symptoms of P0155 on Audi e-tron

When the Engine Control Module (ECM/PCM) on your Audi e-tron (Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP)) logs fault code P0155, drivers commonly observe:

Check Engine Light on immediately after cold start on Audi e-tron (Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP))
Slightly increased cold-start emissions on Audi e-tron (Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP))
No major driving performance issues once engine reaches full operating temperature on Audi e-tron (Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP))
Audi e-tron OBD-II Port Location
The 16-pin diagnostic connector is located Driver footwell near OBD bulkhead interface. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Audi e-tron

Historical warranty claims and technical repair bulletins for Audi e-tron point to the following failure distribution:

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

3. Step-by-Step DIY Repair Guide for Audi e-tron

01
Check O2 Heater Fuse

Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on the Audi e-tron equipped with Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP).

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 Audi e-tron equipped with Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP).

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 Audi e-tron equipped with Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP).

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 Audi e-tron equipped with Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP).

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

Equipment for Diagnosing Audi e-tron (P0155)

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Direct-Fit Replacement Part

Audi e-tron OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Audi e-tron.

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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 Audi e-tron

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Audi e-tron:

4. Audi e-tron P0155 FAQs

What causes code P0155 to trigger on a Audi e-tron?

On the Audi e-tron (Dual Motor AWD (400HP / e-tron GT quattro 469HP / RS 590HP)), 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 Audi e-tron?

On the Audi e-tron, the 16-pin DLC diagnostic connector is located Driver footwell near OBD bulkhead interface. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Audi e-tron 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.