Powertrain, generic (extended)

P2222 NOx Sensor Heater Sense Circuit Range/Performance (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

With P2222 the heater feedback of the bank 2 NOx sensor is electrically present, yet what it reports does not match the heating command: the cell warms too slowly or settles at the wrong resistance. No manufacturer documents this bank 2 code. Two bank 1 descriptions show the approach. GM's 3.0L LZ0 (P2209) compares raw heater resistance with its target and fails a deviation over 3 percent in 50 of 100 samples, only after 45 s of good supply and 180 s past the dew point, Type B. Ford's diesel summary uses the matching rear sensor code P220F for heater current below 0.4 A or a duty cycle more than 20 percent off. An aged heater or weak supply is typical. P2221 is the general sense fault.

Likely causes

Aged heater in the bank 2 NOx probe with drifted resistance
Low supply voltage or poor ground at the sensor module
Heater wiring with added resistance

Symptoms

  • Malfunction indicator lamp on
  • Bank 2 NOx sensor slow to become ready after a cold start
  • SCR monitor for bank 2 delayed

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€150–1,000
Time0.7–3 h

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

Parts involved

nox sensornox sensor heater

Related codes

P2209P2221P2223P2224P220F

References: law.cornell.edu, gsi.ext.gm.com, fordservicecontent.com.