Powertrain, generic (extended)

P2225 NOx Sensor Heater Sense Circuit Intermittent (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2225 covers a heater sense circuit on the bank 2 NOx sensor that fails only for moments: the feedback drops out or jumps, then returns to normal, which a steady open or short code would not describe. No manufacturer documents thresholds for P2225 or for its bank 1 twin P2212. GM's 3.0L LZ0 tables handle only the persistent faults on the HTemp pin (P2208, P2210, P2211) and mention that the Continental sensors debounce electrical errors for 1.5 s internally, so very short glitches may never reach the engine computer. Smart sensors flag heater faults over CAN. Look for a cracked conductor that opens when hot, a loose terminal or moisture. The warning lamp may switch on and off between drives.

Likely causes

Loose or corroded contact in the bank 2 sensor connector
Cracked sense conductor that opens with heat or vibration
Sporadic fault in the heater measurement of the sensor module

Symptoms

  • Malfunction indicator lamp that comes and goes
  • Bank 2 NOx value briefly invalid

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–900
Time0.5–3 h

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

Parts involved

nox sensornox sensor heaternox sensor wiring

Related codes

P2212P2221P2223P2224P2217

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