P220BNOx Sensor Supply Voltage Circuit (Bank 1 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
- P220B concerns the second NOx sensor on bank 1, the one behind the SCR catalyst whose reading proves how well NOx is being converted. Its operating voltage is outside the allowed band. Ford applies the same 8.5 to 16.5 V window as for the front sensor; GM's 3.0L LZ0 flags under 9.9 V (Type B), and VW's 2014 Touareg TDI compares battery and sensor supply, faulting a gap above 1.5 V. GM's 2018 Equinox and Terrain with the 1.6L diesel (LH7) could log P220B through a software issue; PIP5615A points to bulletin 19-NA-009 and an ECM calibration. Volvo and Mack class it as a supply problem, not a sensor failure. Without this sensor the catalyst efficiency check cannot run. P220A is the front sensor.
- What you may notice
- Malfunction indicator lamp on
- Downstream NOx sensor shows no value
- SCR efficiency monitor stays incomplete
- Likely causes
- LikelyFuse, relay or ground fault in the downstream sensor supply
- PossibleSupply wire to the rear sensor damaged under the vehicle
- RareECM calibration (GM 1.6L LH7 2018, PIP5615A / 19-NA-009)
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €0 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.