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P0155LexusLexus ES HubAll Lexus P0155Medium Severity

P0155 on Lexus ES

O2 Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

Factory diagnostic protocol and troubleshooting wire for fault code P0155 specifically for the Lexus ES (2020–2026, 3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD).

Verified OEM Telemetry & Field Repair Tree
Lexus ES2020–2026
Lexus ES
Sedan3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD
Reliability
Sensor Voltage Ref
0.1V – 5.0V Ref
ES 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 Lexus Model:
Diagnose P0155 on Specific ES Model Year:

1. Symptoms of P0155 on Lexus ES

When the Engine Control Module (ECM/PCM) on your Lexus ES (3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD) logs fault code P0155, drivers commonly observe:

Check Engine Light on immediately after cold start on Lexus ES (3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD)
Slightly increased cold-start emissions on Lexus ES (3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD)
No major driving performance issues once engine reaches full operating temperature on Lexus ES (3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD)
Lexus ES OBD-II Port Location
The 16-pin diagnostic connector is located Directly under driver dash, left side of steering column. Plug in your scan tool to verify freeze-frame sensor values.

2. Most Likely Causes on Lexus ES

Historical warranty claims and technical repair bulletins for Lexus ES point to the following failure distribution:

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

3. Step-by-Step DIY Repair Guide for Lexus ES

01
Check O2 Heater Fuse

Inspect the O2 HTR fuse in the engine fuse box with a test light or multimeter. on the Lexus ES equipped with 3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD.

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 Lexus ES equipped with 3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD.

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 Lexus ES equipped with 3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD.

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 Lexus ES equipped with 3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD.

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

Equipment for Diagnosing Lexus ES (P0155)

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Direct-Fit Replacement Part

Lexus ES OEM Replacement Sensor

4.7 / 5.0 (Verified Fit)

Direct-fit replacement assembly engineered to OEM tolerances for Lexus ES.

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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.

$29.99 Prime
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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 Lexus ES

Frequently diagnosed powertrain, emissions, and sensor trouble codes logged on the Lexus ES:

4. Lexus ES P0155 FAQs

What causes code P0155 to trigger on a Lexus ES?

On the Lexus ES (3.5L V6 (2GR-FKS 302HP) / 2.5L Hybrid (ES 300h 215HP) / 2.5L AWD), 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 ES?

On the Lexus ES, the 16-pin DLC diagnostic connector is located Directly under driver dash, left side of steering column. 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 ES 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.