Powertrain, generic (extended)

P220B NOx Sensor Supply Voltage Circuit (Bank 1 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

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.

Likely causes

Fuse, relay or ground fault in the downstream sensor supply
Supply wire to the rear sensor damaged under the vehicle
ECM calibration (GM 1.6L LH7 2018, PIP5615A / 19-NA-009)

Symptoms

  • Malfunction indicator lamp on
  • Downstream NOx sensor shows no value
  • SCR efficiency monitor stays incomplete

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€0–800
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

nox sensor

Related codes

P220AP220CP220DP229EU029E

References: fordservicecontent.com, gsi.ext.gm.com, static.nhtsa.gov, static.nhtsa.gov.