O2 Sensor Heater Resistance High (Bank 2, Sensor 1)
The P0059 code indicates that the powertrain control module (PCM) has detected a high resistance in the heater circuit of the oxygen sensor located before the catalytic converter on bank 2 (the side of the engine not containing cylinder #1). The heater element is essential for the sensor to reach operating temperature quickly, especially during cold starts. High resistance can be caused by a faulty sensor, damaged wiring, or poor electrical connections, leading to inaccurate air-fuel ratio readings and increased emissions.
1. Most Common Causes
- Faulty oxygen sensor (Bank 2, Sensor 1)
- Damaged or corroded wiring/connectors in the heater circuit
- Blown fuse or relay for the O2 sensor heater
- PCM issue (rare)
2. Symptoms You Will Notice
- Check Engine Light illuminated
- Failed emissions test
- Decreased fuel economy
- Rough idle or hesitation
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for other related codes.
Step 2: Visually inspect the wiring and connector for Bank 2, Sensor 1 for damage, corrosion, or loose connections.
Step 3: Measure the resistance of the heater circuit at the sensor connector using a multimeter (typically 2-10 ohms). Compare to manufacturer specs.
Step 4: Check the heater circuit fuse and relay; replace if blown.
Step 5: If all else is good, replace the oxygen sensor.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
You can drive short distances, but it may cause poor fuel economy and increased emissions. Prolonged driving could damage the catalytic converter.
How much does it cost to fix?▼
Typically $50-$150 for a DIY sensor replacement, or $150-$300 at a shop including labor.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.