OBD-II code · Powertrain (generic, extended)
P22BD O2 Sensor Reference Voltage Circuit Low (Bank 2 Sensor 2)
O2 reference voltage on bank 2 sensor 2 below lower plausibility — short to ground. A drifted or sluggish lambda sensor lets the mixture run lean or rich without correction — fuel economy and emissions suffer immediately.
Is it safe to drive with P22BD?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
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
- 0.5–2.5 h
- Emissions test
- Likely to fail
- Parts involved
- Oxygen Sensor
Related codes
- P2245O2 Sensor Reference Voltage Circuit Low (Bank 1 Sensor 1)
- P2249O2 Sensor Reference Voltage Circuit Low (Bank 2 Sensor 1)
- P22B0O2 Sensor Reference Voltage Circuit Low (Bank 1 Sensor 2)
- P22BAO2 Sensor Positive Current Control Circuit High (Bank 2 Sensor 2)
- P22BBO2 Sensor Reference Voltage Circuit/Open (Bank 2 Sensor 2)
- P22BCO2 Sensor Reference Voltage Performance (Bank 2 Sensor 2)
- P22BEO2 Sensor Reference Voltage Circuit High (Bank 2 Sensor 2)
- P22BFO2 Sensor Negative Current Control Circuit/Open (Bank 2 Sensor 2)
- P22C0O2 Sensor Negative Current Control Circuit Low (Bank 2 Sensor 2)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.