Powertrain, generic (extended)

P22BA O2 Sensor Positive Current Control Circuit High (Bank 2 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P22BA is set when the pump-current (positive current control) wire of the bank 2 downstream wide-band probe is held above its normal bias, typically through contact with the heater supply or a damaged connector letting battery voltage in. No maker documents this code publicly. Related evidence comes from bank 1 and the front sensors: GM names P22AD for the 3.0 Duramax LM2 in a harness-chafing bulletin, Saab measures about 2.8 V on the pump pins of a healthy upstream probe and rates P2239 as Type B, and Ford reports upstream shorts to power as P0132. The code only applies to dual-bank engines with a wide-band probe after each catalyst. P22B8 is the open, P22B9 the low code, P22AD bank 1. Expect the warning lamp.

Likely causes

Pump-current wire shorted to the heater feed or battery voltage
Heater-to-pump-cell leakage inside the sensor
Faulty sensor interface in the ECM

Symptoms

  • Check engine light
  • Bank 2 downstream oxygen value implausibly high

Repair estimate

DifficultyMediumDIY possible
Parts and labour€50–450
Time0.5–2.5 h

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

Parts involved

oxygen sensor bank2 sensor2oxygen sensor wiringecm

Related codes

P22B8P22B9P22ADP2242

References: law.cornell.edu, saabwisonline.com, static.nhtsa.gov.