OBD-II code · Powertrain (generic, extended)
P2243 O2 Sensor Reference Voltage Circuit (Bank 1 Sensor 1)
The reference voltage line that powers the wide-band sensor cell on bank 1 sensor 1 is missing or out of tolerance. Without correct reference, the AFR calculation is invalid.
Is it safe to drive with P2243?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyReference voltage line open
- PossibleWide-band sensor failed
Symptoms
- Check engine light on
- Increased fuel consumption
- Possible rough idle or hesitation
- Failed emissions test
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–2 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Oxygen Sensor Wideband, Oxygen Sensor Wiring
Related codes
- P2237O2 Sensor Pumping Current Circuit (Bank 1 Sensor 1)
- P2247O2 Sensor Reference Voltage Circuit (Bank 2 Sensor 1)
- P2240O2 Sensor Pumping Current Circuit (Bank 2 Sensor 1)
- P2241O2 Sensor Pumping Current Circuit Low (Bank 2 Sensor 1)
- P2242O2 Sensor Pumping Current Circuit High (Bank 2 Sensor 1)
- P2244O2 Sensor Reference Voltage Circuit Range/Performance (Bank 1 Sensor 1)
- P2245O2 Sensor Reference Voltage Circuit Low (Bank 1 Sensor 1)
- P2246O2 Sensor Reference Voltage Circuit High (Bank 1 Sensor 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.