Powertrain, generic (extended)

P22B3 O2 Sensor Negative Current Control Circuit Low (Bank 1 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P22B3 reports the negative current control line, i.e. the virtual ground of the bank 1 downstream wide-band probe, as too low. Normally the controller lifts this common return to a bias near 2.5 V (Saab measures that at the plug of its 2010 9-5) so that pump current can flow in both directions; a short to chassis ground collapses the bias and with it the measuring range. No maker documents this exact code publicly. Mitsubishi lists the upstream analog P2252 as a two-trip code for the 2022 Outlander, and Ford handles upstream shorts under P0131 instead. P22B2 is the open-circuit code, P22B4 the high one, P22C0 the bank 2 version. Apart from the warning lamp, the driver rarely notices anything.

Likely causes

Return wire shorted to chassis ground through chafed insulation
Internal short inside the wide-band sensor
Faulty bias supply in the ECM or sensor module

Symptoms

  • Check engine light
  • Downstream oxygen value implausible or pinned

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 bank1 sensor2oxygen sensor wiringecm

Related codes

P22B2P22B4P22C0P2252P22AC

References: static.nhtsa.gov, saabwisonline.com, bosch-motorsport.com, newtonnet.co.uk.