P0155 on Lexus: Symptoms, Causes & Fix
Official technical diagnostic wire for fault code P0155 specifically affecting Lexus vehicles (ES, RX, NX, GX, LX).
Select Your Lexus Model for P0155:
1. Common Symptoms on Lexus Vehicles
When Lexus Engine Control Modules (ECM) trigger fault code P0155, drivers typically report:
2. Root Causes on Lexus Engines
Historical diagnostic claims across Lexus engines point to the following failure distribution:
3. Step-by-Step Fix Protocol for Lexus
Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on Lexus engines.
Unplug the sensor connector and measure resistance between the two heater pins. An open circuit (infinite ohms / OL) confirms a dead internal heater. on Lexus engines.
Remove faulty sensor and install a new OEM oxygen sensor with built-in heater. on Lexus engines.
Clear DTCs and allow engine to cool down, then restart to confirm P0155 does not return. on Lexus engines.
Equipment for Diagnosing Lexus (P0155)
Lexus OEM Replacement Sensor
Direct-fit replacement assembly engineered to OEM tolerances for Lexus.
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.
4. Lexus P0155 Frequently Asked Questions
What does code P0155 mean on a Lexus?
On Lexus vehicles, P0155 indicates that the Engine Control Module (ECM) detected o2 sensor heater circuit malfunction (bank 2 sensor 1). This typically points to Burnt-out heating element inside the Bank 2 Sensor 1 O2 sensor or Blown O2 heater fuse in under-hood fuse block.
Can I continue driving my Lexus with code P0155?
Yes. The sensor will take longer to warm up, causing brief open-loop fuel delay on cold starts. Because this code carries a Medium severity rating on Lexus powertrains, we recommend scanning live data values promptly to prevent secondary damage.
How much does it cost to fix code P0155 on a Lexus?
Estimated DIY parts cost ranges from $120 - $350 (DIY: $45 - $120), while professional shop repairs at an authorized Lexus dealership or independent specialist typically range from $180 to $380 including diagnostic labor.