P2223 NOx Sensor Heater Sense Circuit Low (Bank 2)

P2223 indicates that the heater sense line of the bank 2 NOx sensor sits at or near ground potential, so the electronics reads an impossibly low value for heater resistance. A sense conductor rubbed through to the exhaust bracket or a shorted measuring input inside the sensor module are the usual explanations. No manufacturer publishes the bank 2 code. For bank 1, GM's 3.0L LZ0 tables carry the equivalent P2210 as a grounded HTemp pin, judged on 80 failed of 160 samples with the powertrain relay above 11 V, Type B, so the MIL waits for a second trip. With no usable feedback the sensor cannot hold its working temperature. P2224 is the opposite polarity, P2219 a low fault on the control side.

Likely causes

Symptoms

• Malfunction indicator lamp on after two trips
• No valid NOx value from bank 2

Repair estimate

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

Parts involved

Related codes

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