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P0155 on Nissan Sentra

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Factory diagnostic protocol and troubleshooting wire for fault code P0155 specifically for the Nissan Sentra (2020–2026, 2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic)).

Verified OEM Telemetry & Field Repair Tree
Nissan Sentra2020–2026
Nissan Sentra
Sedan2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic)
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
Sentra 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 Nissan Model:
Diagnose P0155 on Specific Sentra Model Year:

1. Symptoms of P0155 on Nissan Sentra

When the Engine Control Module (ECM/PCM) on your Nissan Sentra (2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic)) logs fault code P0155, drivers commonly observe:

Check Engine Light on immediately after cold start on Nissan Sentra (2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic))
Slightly increased cold-start emissions on Nissan Sentra (2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic))
No major driving performance issues once engine reaches full operating temperature on Nissan Sentra (2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic))
Nissan Sentra OBD-II Port Location
The 16-pin diagnostic connector is located Driver lower dash cover above brake pedal. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Nissan Sentra

Historical warranty claims and technical repair bulletins for Nissan Sentra point to the following failure distribution:

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

3. Step-by-Step DIY Repair Guide for Nissan Sentra

01
Check O2 Heater Fuse

Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on the Nissan Sentra equipped with 2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic).

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 Nissan Sentra equipped with 2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic).

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 Nissan Sentra equipped with 2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic).

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 Nissan Sentra equipped with 2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic).

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

Equipment for Diagnosing Nissan Sentra (P0155)

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Sensor Signal Voltage Meter

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Other Common Fault Codes on Nissan Sentra

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Nissan Sentra:

4. Nissan Sentra P0155 FAQs

What causes code P0155 to trigger on a Nissan Sentra?

On the Nissan Sentra (2.0L DOHC 16V 4-Cyl (149HP / CVT Xtronic)), 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 Nissan Sentra?

On the Nissan Sentra, the 16-pin DLC diagnostic connector is located Driver lower dash cover above brake pedal. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.

Can I safely drive my Nissan Sentra 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.