P0059
UniversalHO2S Heater Resistance (Bank 2, Sensor 1)
The oxygen sensor at Bank 2, Sensor 1 has an associated heater that helps it reach operating temperature. The engine controller monitors the heater’s electrical resistance and has detected a condition outside its expected range. This can delay accurate oxygen-sensor readings, particularly when the engine is cold, and may affect emissions or engine operation. The code identifies a detected condition, not proof that the sensor itself has failed.
⚠️ Before You Begin (Safety First)
This fault usually does not require stopping immediately. Arrange diagnosis soon, since delayed sensor operation can increase emissions or affect drivability. Stop driving if the engine runs severely rough, loses power, or the check-engine light flashes; those signs may indicate a more urgent problem.
Common Symptoms
- The check-engine light may be on, with no noticeable change in how the vehicle drives.
- The sensor may take longer to provide useful readings after a cold start, which can affect emissions control during warm-up.
- Fuel economy or engine smoothness may be affected in some cases, depending on how the vehicle responds to delayed sensor readings.
- An emissions test may be affected if the heater fault prevents the sensor or emissions system from operating as intended.
Common Causes
- The oxygen sensor’s heater element may have an electrical resistance problem.
- Wiring to the heater circuit may be damaged, chafed, or otherwise electrically compromised.
- A connector may be loose, corroded, or damaged.
- A power, ground, or control-side issue in the heater circuit may affect the monitored resistance.
- A related circuit protection component may be faulty, if applicable to the vehicle.
Diagnostic Steps
- Confirm the code with a compatible scan tool and note any other codes; related codes can help identify whether the issue is limited to the heater circuit.
- Use vehicle-specific service information to identify Bank 2, Sensor 1, since sensor locations vary by engine.
- With the vehicle safely parked, engine off, and exhaust cooled, visually inspect the sensor wiring and connector for damage, looseness, corrosion, or contact with hot or moving parts.
- If an obvious connector or wiring issue is found, address it only if you can do so safely and correctly; avoid pulling on wires or working near a hot exhaust.
- If the code returns or no visible issue is found, have the heater circuit and sensor tested using the vehicle-specific procedure rather than replacing the sensor based on the code alone.
When to Call a Professional
A technician can confirm which sensor is Bank 2, Sensor 1 for the specific vehicle, review scan data, and test the heater circuit, wiring, connector, and sensor resistance against vehicle-specific specifications. The fault should be diagnosed before replacing parts; exact test procedures depend on model, year, and engine.
Compare component listings
Confirm diagnosis and vehicle fitment before buying. A listing does not prove that a part needs replacement. We may earn a commission from qualifying purchases.
Commonly Asked Questions
Does P0059 prove that the oxygen sensor needs replacement?
No. It indicates a detected heater-resistance condition for Bank 2, Sensor 1. Wiring, the connector, or another part of the heater circuit may also be responsible.
What does the sensor heater do?
It helps the oxygen sensor reach operating temperature so it can provide useful exhaust-oxygen readings sooner, especially after a cold start.
Can I keep driving with P0059?
Often the vehicle can be driven cautiously if it runs normally, but diagnosis should not be put off. Stop if it runs severely rough, loses power, or the check-engine light flashes.
Where is Bank 2, Sensor 1?
Its location depends on the engine layout. Use service information for the specific vehicle to identify Bank 2 and the sensor positioned before the relevant catalytic converter.
Related Diagnostic Video
Browse Available Code Guides
Previous and next available guides in database record order, across makes. Adjacent entries may share a code number and do not necessarily describe related faults.