Powertrain, generic (extended)

P22AB O2 Sensor Positive Current Control Circuit/Open (Bank 1 Sensor 2)

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modeNo

P22AB reports a break in the positive current control line of a wide-band probe mounted behind the catalyst or, on diesels, further down the aftertreatment on bank 1. On a Bosch-style five-wire probe this is the pump-current lead (IP/APE) through which the controller moves oxygen into or out of the pump cell. Chrysler lists the code for 2010-2012 Ram 2500/3500 pickups with the 6.7 Cummins in bulletins 25-004-12 and 25-002-14; the prescribed fix is new sensor connectors or an overlay harness before any sensor is replaced. GM names it in 21-NA-149 among faults from chafed harnesses on the 3.0 Duramax LM2. P22AC/P22AD cover low/high, P22B8 is bank 2, P2237 the upstream twin. The warning lamp comes on; the engine usually runs normally.

Likely causes

Corroded, loose or poorly crimped terminal in the sensor or sensor-module connector

Pump-current wire broken or chafed through along the exhaust

Internal open circuit in the downstream wide-band sensor

Symptoms

Check engine light
Downstream oxygen reading frozen or missing in live data
Related catalyst or aftertreatment monitors stay incomplete

Repair estimate

DifficultyMediumDIY possible

Parts and labour€0–450

Time0.5–2.5 h

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

Parts involved

oxygen sensor bank1 sensor2oxygen sensor wiringecm

References: static.nhtsa.gov, static.nhtsa.gov, static.nhtsa.gov, bosch-motorsport.com.