P220ANOx Sensor Supply Voltage Circuit (Bank 1 Sensor 1)
- 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
- A smart NOx sensor draws its own operating power, mostly for the probe heater. P220A means the supply reaching the upstream sensor on bank 1 is outside its window. Ford's 6.7L and 3.0L diesels flag above 16.5 V or below 8.5 V; GM's 3.0L Duramax (LZ0) flags below 9.9 V while the engine runs, Type B after two trips. On the 6.6L LML, GM feeds the sensor from a DC/DC booster in the glow plug module and sets P220A when that module reports its output shorted or overloaded (Type B). VW's 2014 Touareg TDI uses a 1.5 V deviation. Volvo and Mack advise checking supply wiring, fuses and relays rather than the sensor. P220B is the downstream sensor, P220C/P220D bank 2. The sensor stays inactive.
- What you may notice
- Malfunction indicator lamp on
- Upstream NOx sensor shows no value or no communication
- Other NOx sensor codes stored at the same time
- Likely causes
- LikelyBlown fuse, faulty relay or poor ground in the sensor supply
- PossibleSupply wire chafed, corroded or with high resistance
- PossibleSupply booster in the glow plug control module (GM 6.6L LML)
- RareWeak battery or charging-system voltage out of range
- 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: €30 – €800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.