P22BDO2 Sensor Reference Voltage Circuit Low (Bank 2 Sensor 2)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P22BD reports that the Nernst-cell (reference voltage) lead of the bank 2 post-catalyst wide-band probe sits below its valid window. Bosch allows the cell a load of only about 250 microamps, so a lead whose insulation touches ground, or moisture bridging the plug, pulls the signal down quickly. No maker documents this code publicly. Upstream practice shows how close low and open lie: VW's 2014 Touareg data book counts a Nernst voltage under 0.25 V with cell resistance above 950 ohms as an open circuit (P2247), and Ford sends shorts to ground on its front probes to P0151 for bank 2. JLR names the bank 1 front analog P2245 in a bulletin on probes cracked by water splash. P22BB is the open, P22BE the high case, P22B0 bank 1. Mostly only the lamp shows.
- What you may notice
- Check engine light
- Bank 2 downstream oxygen value missing or at the lower end in live data
- Likely causes
- LikelyNernst-cell lead chafed through and touching ground
- PossibleWater or corrosion creating a leakage path in the connector
- PossibleSensing element cracked by water contact on the hot probe
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €50 – €450
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.