Powertrain, generic (extended)

P2224 NOx Sensor Heater Sense Circuit High (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2224 is logged when the heater sense signal of the bank 2 NOx sensor is too high, which the electronics sees as a short to supply voltage or as an interrupted heater reading near infinite resistance. The bank 2 code appears in no public manufacturer document. GM documents the bank 1 version P2211 for the 3.0L LZ0 as an HTemp pin shorted toward supply: 80 failed of 160 samples, powertrain relay above 11 V, sensor bus relay switched on, Type B over two trips. Since the sensor module cannot judge cell temperature, it holds back its NOx value and SCR control for that bank falls back on modelled emissions. P2223 is the low direction, P2220 a high fault on the control side, P2225 a sporadic sense fault.

Likely causes

Heater element in the bank 2 probe open, read as maximum resistance
Sense lead shorted to a voltage source
Fault in the sensor module input stage

Symptoms

  • Malfunction indicator lamp on after two trips
  • Bank 2 NOx sensor stays unready

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€150–1,000
Time0.5–2.5 h

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

Parts involved

nox sensornox sensor heaternox sensor wiring

Related codes

P2211P2221P2223P2225P2220

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