Powertrain, generic (extended)

P22BE O2 Sensor Reference Voltage Circuit High (Bank 2 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P22BE is stored when the reference voltage lead of the bank 2 downstream wide-band probe carries more voltage than a working Nernst cell can produce. A healthy cell produces well under one volt from a source of roughly 300 ohms, so contact with the heater feed, a 5 V line or battery voltage swamps it, and a cracked ceramic can let heater potential leak into the cell. No maker documents this code publicly. On upstream probes the top of the scale is already an open-circuit criterion: Ford and Saab react above 4.7 V, VW's Touareg above 4.80 V, while Ford files shorts to battery under P0152 for bank 2. Under CARB rules a secondary sensor must also be checked for readings outside its range. P22BB is the open, P22BD the low reading, P22B1 bank 1. The lamp comes on.

Likely causes

Nernst-cell lead shorted to the heater supply or another live wire
Cracked ceramic letting heater voltage into the sensing cell
Faulty sensor interface in the engine control module

Symptoms

  • Check engine light
  • Bank 2 downstream oxygen reading pinned at the upper limit
  • Heater codes for the same sensor may appear alongside

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

P22BBP22BCP22BDP22B1P2250

References: law.cornell.edu, bosch-motorsport.com, newtonnet.co.uk, saabwisonline.com.