P0135 on the 2023 Honda Pilot
The 2023 Honda Pilot was completely redesigned (4th generation), now riding on a new platform with an updated 3.5L V6 engine producing 285 horsepower paired with a 10-speed automatic transmission. The P0135 code means the heater circuit in the Bank 1 upstream O2 sensor has malfunctioned. On the Pilot's transverse V6, Bank 1 is typically the rear bank, and Sensor 1 sits before the catalytic converter.
The Redesigned 2023 Pilot and O2 Sensors
The 2023 Pilot's new platform features a redesigned exhaust system with updated sensor placement and wiring routing. The 3.5L V6 was refined for this generation with improved thermal management. Despite these improvements, individual sensor or circuit issues can still occur, particularly on a first-year redesign where production processes are being refined.
Causes on the New Pilot
- Factory sensor heater defect: An individual sensor with a manufacturing flaw in the heater element. First-year models may have slightly higher rates of isolated component failures as the supply chain calibrates production.
- Heater circuit fuse issue: A loose, defective, or improperly rated fuse in the underhood box can prevent the heater from operating.
- Assembly wiring concern: On the redesigned platform, new wiring routing may expose the heater circuit to unexpected heat sources or vibration contact points.
- ECM software refinement: Honda may issue software updates that adjust heater circuit monitoring parameters for the new platform.
Warranty Coverage
Your 2023 Pilot is under Honda's 3-year/36,000-mile basic warranty and the federal 8-year/80,000-mile emissions warranty. This repair should be performed at no cost at any authorized Honda dealer.
What the Dealer Will Do
- Verify P0135 using Honda Diagnostic System (HDS).
- Check the O2 heater fuse and heater circuit power supply.
- Test heater element resistance at the sensor connector.
- Review TSBs and software updates for the 2023 Pilot.
- Replace sensor, repair wiring, or update software as needed.
Reference Costs
Under warranty: $0. Post-warranty: OEM sensor for the V6: $95-$185. Dealer labor for rear bank: $150-$300. Total: $245-$485. Honda dealer labor: $130-$180/hour.
First-Year Redesign Notes
The 2023 Pilot is a first-year redesign, so some minor teething issues are expected as production quality stabilizes. A single P0135 code does not indicate broader reliability problems. Keep documentation of all warranty repairs for your records.