P0155 on Lexus NX
Factory diagnostic protocol and troubleshooting wire for fault code P0155 specifically for the Lexus NX (2022–2026, 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP)).
1. Symptoms of P0155 on Lexus NX
When the Engine Control Module (ECM/PCM) on your Lexus NX (2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP)) logs fault code P0155, drivers commonly observe:
2. Most Likely Causes on Lexus NX
Historical warranty claims and technical repair bulletins for Lexus NX point to the following failure distribution:
3. Step-by-Step DIY Repair Guide for Lexus NX
Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on the Lexus NX equipped with 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP).
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 Lexus NX equipped with 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP).
Remove faulty sensor and install a new OEM oxygen sensor with built-in heater. on the Lexus NX equipped with 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP).
Clear DTCs and allow engine to cool down, then restart to confirm P0155 does not return. on the Lexus NX equipped with 2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP).
Equipment for Diagnosing Lexus NX (P0155)
Lexus NX OEM Replacement Sensor
Direct-fit replacement assembly engineered to OEM tolerances for Lexus NX.
AstroAI Auto-Ranging Digital Multimeter
Essential for testing 0.1V–5.0V sensor reference signals, ground continuity (<0.20Ω), and harness resistance.
BlueDriver Bluetooth Pro OBDII Scan Tool
Reads and clears enhanced codes (ABS, Airbag, Transmission, Engine) & live freeze-frame telemetry on phone.
Other Common Fault Codes on Lexus NX
Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Lexus NX:
4. Lexus NX P0155 FAQs
What causes code P0155 to trigger on a Lexus NX?
On the Lexus NX (2.5L 4-Cyl / 2.4L Turbo (275HP) / 2.5L Hybrid (NX 350h) / PHEV (NX 450h+ 304HP)), 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 Lexus NX?
On the Lexus NX, the 16-pin DLC diagnostic connector is located Under driver dash near footwell illumination lamp. Plug in any standard OBD-II scanner with the ignition in the ON position to read freeze-frame parameters.
Can I safely drive my Lexus NX 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.