Powertrain, generic (extended)

P2218 NOx Sensor Heater Control Circuit/Open (Bank 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

A NOx sensor cannot measure until its built-in heater has taken the ceramic cell to several hundred degrees, and the sensor electronics switches that heater itself. P2218 reports a break in the heater control path of the bank 2 sensor, either inside the probe or in the lead to the sensor module. No manufacturer documents the bank 2 version. The bank 1 code P2205 is well described: GM's 6.6L LML sets it when an open heater is reported longer than 10 s with the battery at 11 V or more, the 3.0L LZ0 on an open load at the heater control pin, both Type A with the MIL after one trip. Without heating, the bank 2 sensor never becomes ready. P2219 and P2220 are the shorted cases, P2221 the heater sense side.

Likely causes

Heater element in the bank 2 NOx probe burnt through
Broken conductor between probe and sensor module
Pushed-back or corroded pin in the sensor connector

Symptoms

  • Malfunction indicator lamp on after one trip
  • Bank 2 NOx sensor never reports ready

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 heater

Related codes

P2205P2219P2220P2221P2213

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