OBD-II trouble code
P0059: HO2S Heater Resistance (Bank 2, Sensor 1)
Application matters: Bank 2 does not contain cylinder 1. Identify the actual sensor, heater technology and connector from the vehicle’s exhaust/circuit diagram.
P0059 reports an abnormal heater-resistance result for bank 2 sensor 1. Diagnose the complete manufacturer code and permitted heater tests before choosing a sensor, circuit or control repair.
Quick facts
- System
- Powertrain
- Category
- Oxygen Sensor
- Severity
- Medium severity
- Driving guidance
- Depends on symptoms and vehicle guidance
- Repair cost range
- $440 – $523 (oxygen-sensor replacement, parts and labor; conditional job example)
- DIY difficulty
- Shop recommended
A code alone cannot establish whether driving is safe. Stop safely for a red brake or oil-pressure warning, overheating, severe misfire, stalling, or impaired braking or steering, and follow the owner's manual. Restraints faults can reduce crash protection even when the vehicle runs normally.
Part of a family with 24 codes
P0059 is one of 24 codes covering oxygen sensor heater circuit faults. The identifier must be matched to the exact vehicle. Related codes can share a diagnostic approach, but their circuit, failure condition, and required tests can differ.
Browse every code in P0001–P00C6, or start from the full code library.
What does P0059 mean?
The controller’s heater-resistance monitor reported an abnormal result for bank 2 sensor 1. A heater-resistance designation does not mean a scan tool directly measured the disconnected sensor with an ohmmeter. The controller’s measurement method, temperature, command state and monitor prerequisites determine the result.
Ford’s July 2024 operation summary pairs P0059 with P0050_1E and reports heater-current information. Mitsubishi’s 2019 RE/13B P0059 entry evaluates energized bank 2 sensor 1 heater current with defined battery, temperature, elapsed-time and duty prerequisites; it gives a separate disconnected heater check. Neither example establishes a universal whole-loop resistance equation, chassis-ground return design or hand-meter limit.
P0050, P0051 and P0052 are heater-control designations for the same bank/sensor; oxygen-signal and catalyst-efficiency results are different evaluations. A code is not enough to condemn the sensing element, wiring, controller or converter. Even a correct static heater check cannot establish all powered operating behavior.
Possible causes
- An internal heater fault at the identified bank 2 sensor 1, demonstrated by permitted tests
- Damaged or poorly contacting heater terminals, incorrect connector installation or an incompatible replacement component
- A required supply, return/control or conductor fault established using the actual measurement method
- A controller/driver fault after its prerequisites, supplies, circuit and component checks
Symptoms
- Check engine light with P0059 stored
- Abnormal or delayed sensor heating/operation where the actual fault causes it
- Possible effects on an emissions monitor that depends on correct sensor operation
- No obvious driving change in some cases; that does not establish normal heater operation
Diagnostic steps
Save the full scan report, code status, and available freeze-frame data before clearing anything. Confirm the reporting module, any failure-type suffix, and the procedure for the exact vehicle. The steps below are an overview; use manufacturer specifications and safety procedures for testing.
- 1.Save the complete P0059, suffix, status, event data and companion faults before clearing anything. Confirm the actual engine and bank 2 sensor 1.
- 2.Record recent sensor, exhaust, wiring or software work and follow vehicle warnings. Do not use a normal idle as evidence that a damaged-wire or heating fault can be ignored.
- 3.Inspect the correctly identified connector and safely accessible harness with ignition off and exhaust cool. Use proper vehicle support when access is underneath.
- 4.Identify the fitted upstream sensor technology and permitted heater terminals. Follow this bank 2 sensor 1 procedure, including any supply/control faults that must be diagnosed before evaluating the resistance result.
- 5.Have a technician establish required supplies and control operation, then perform the permitted heater/component checks. Use the specified isolation, terminal pair, temperature and limits; do not ohm a powered circuit or probe oxygen-signal terminals as heater terminals.
- 6.Compare commanded heater operation and the actual monitor result only under the specified prerequisites. A passed cold check or a changed unplugged reading does not independently prove which part failed.
- 7.Repair the demonstrated cause and restore correct routing/connections. Complete the required heater/operational verification; code clearing, exhaust heat or an arbitrary road drive is not confirmation.
Repair cost
$440 – $523 (oxygen-sensor replacement, parts and labor; conditional job example)
USD planning figures, not a vehicle-specific quote. Confirm the diagnosed job and whether the estimate includes diagnosis, parts, labor, programming, calibration, and taxes.
RepairPal national average updated September 3, 2026, checked November 6. Applies only if oxygen-sensor replacement is diagnosed. Excludes taxes, fees, location differences and related repairs. Diagnosis, wiring, connectors, programming and catalytic-converter work require separate quotes; no bank/sensor-specific price is implied.
Estimate your repair
Run the numbers for your vehicle
Open the Repair Cost Estimator with check engine light diagnosis preselected. Adjust labor rate and vehicle category to fit your situation.
Related repairs
These links are planning examples; the code does not confirm that any listed part has failed.
DIY vs shop
A qualified shop is recommended because this can involve manufacturer-grade tooling, training, or certification that most home setups do not have. Ask the technician what testing confirmed the repair.