Powertrain, generic (extended)

P2200 NOx Sensor Circuit (Bank 1 Sensor 1)

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P2200 is the general electrical fault reported for the front NOx sensor on bank 1, the unit ahead of the SCR catalyst. Such sensors carry their own control unit, which checks the probe wiring and reports the result over CAN. GM's 6.6L Duramax (LML) sets P2200 as a Type A fault once an open-circuit status keeps arriving for more than 0.5 s or 10 s, depending on calibration. Ford's 6.7L and 3.0L diesels use it for shorts or opens on the probe lines and for memory checksum errors inside the sensor controller. VW's 2014 Touareg TDI reacts to an error message or a validity ratio of at least 0.5. P2201 covers plausibility, P2202/P2203 a value out of range, P229E the downstream sensor. Dosing loses its feedback and the MIL comes on.

Likely causes

Internal fault in the NOx probe or its attached control unit

Damaged cable between probe and sensor control unit (heat, chafing)

Moisture or corrosion in the sensor connector

Unstable supply or ground at the sensor control unit

Symptoms

Malfunction indicator lamp on
No NOx value in live data from the upstream sensor
SCR or emissions warning, possibly followed by inducement countdown

Repair estimate

DifficultyMediumDIY possible

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 wiring

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