Powertrain, generic (extended)

P220D NOx Sensor Supply Voltage Circuit (Bank 2 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P220D covers the last position in this group: the downstream NOx sensor on bank 2, after that bank's own SCR catalyst, has a supply voltage outside its window. It only exists on engines whose two banks keep separate aftertreatment, which none of the publicly documented diesel applications do; no manufacturer lists the code with thresholds. Ford's bank 1 rear sensor code P220B uses 8.5 to 16.5 V, a useful reference. A dead rear sensor means the efficiency monitor for the bank 2 catalyst cannot finish. CARB requires NOx sensor diagnostics to catch wiring breaks and readings beyond range. P220C is the upstream sensor on the same bank, P220B the rear sensor on bank 1. Check supply fuse, ground and connector first.

Likely causes

Supply fuse, relay or ground fault for the bank 2 rear sensor
Corroded connector exposed to road spray behind the catalyst
Internal fault in the supply stage of the sensor module

Symptoms

  • Malfunction indicator lamp on
  • SCR efficiency monitor for bank 2 not completed

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€30–800
Time0.5–3 h

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

Parts involved

nox sensor

Related codes

P220AP220BP220CP221B

References: law.cornell.edu, fordservicecontent.com, hella.com.