Powertrain, generic (extended)

P22BF O2 Sensor Negative Current Control Circuit/Open (Bank 2 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P22BF means the negative current control lead of the bank 2 post-catalyst wide-band probe has lost continuity. That lead is the common return of pump and Nernst cell (VM/IPN on Bosch, COM on NTK); without it neither cell has a reference and the signal freezes near its bias. No maker documents this code publicly. How an open return is spotted shows in the bank 2 front code P2254: VW's 2014 Touareg data book looks for a signal of 1.47-1.52 V with cell resistance above 950 ohms, and Ford for Bosch-type probes waits for 1.45-1.55 V lasting 10 s. Chrysler lists the bank 1 twin P22B2 for the 6.7 Cummins Ram and replaces connectors first. P22C0/P22C1 are low/high, P22BB the reference lead. The lamp lights; driving feels normal.

Likely causes

Loose, corroded or pushed-out terminal on the return wire
Return wire broken by heat or vibration near the exhaust
Internal break in the sensor lead or element

Symptoms

  • Check engine light
  • Bank 2 downstream oxygen value frozen at a constant reading
  • Further codes for the same sensor may be stored together

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 bank2 sensor2oxygen sensor wiringecm

Related codes

P22C0P22C1P22BBP22B2P2254

References: law.cornell.edu, static.nhtsa.gov, newtonnet.co.uk, static.nhtsa.gov.