P0135
02 Sensor Heater Circuit Malfunction
Description
02 Sensor Heater Circuit Malfunction (Bank 1 Sensor 1) This body system diagnostic trouble code indicates an issue with the vehicle's comfort, safety, or convenience systems.
OBD Codes Details
Possible Causes
Blown fuse, faulty switch, damaged wiring harness, poor electrical connection
Solution
Check fuses and relays, inspect wiring harness, test switches and sensors, repair damaged circuits
Symptoms
- Check engine light illuminated
- No noticeable drivability symptoms in most cases
- Longer engine warm-up before closed-loop operation
- Slightly reduced fuel economy
- Failed emissions test
Diagnostic Recommendations
- Check O2 sensor heater fuse and relay
- Test heater circuit resistance at the sensor connector
- Inspect wiring for heater circuit damage or corrosion
- Verify battery voltage reaches the heater circuit
- Replace O2 sensor if heater circuit is open or shorted
Repair Cost Estimate
- O2 sensor replacement: $150-400
- Fuse/relay replacement: $10-40
- Wiring repair: $80-200
- Diagnostic scan: $80-150
- Total diagnostic and repair: $150-600
Was this helpful?
Loading...
Send Feedback
Found an error or have a suggestion? We respond within 48 hours.
Fact-checking completed
Verified by:
Pavel Volkov
Created:
Last updated:
Information verified against official sources
Official Sources
Society of Automotive Engineers
Official OBD-II diagnostic trouble codes standard (SAE J2012)
Automotive engineering standards organization
International Organization for Standardization
International standard for vehicle diagnostic systems
International standards for automotive diagnostics
Learn More
Dive deeper with our comprehensive developer guides for OBD Codes
Related Codes
More codes of the same type