Powertrain, generic (extended)

P22C0 O2 Sensor Negative Current Control Circuit Low (Bank 2 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P22C0 flags the negative current control line (virtual ground) of the bank 2 downstream wide-band probe as too low. The controller deliberately lifts this return above chassis ground, around 2.5 V on Saab's 2010 9-5, which lets the pump cell be driven both ways; once the wire touches ground, that bias and the lean side of the measuring range disappear. No maker documents this code publicly. Mitsubishi lists the bank 1 front analog P2252 as a two-trip code on the 2022 Outlander without giving a limit, and Ford reports shorts to ground on the VM pin of its front bank 2 probes as P0151 rather than a dedicated code. P22BF is the open, P22C1 the high reading, P22B3 bank 1. Apart from the lamp, little changes for the driver.

Likely causes

Return wire chafed against body or exhaust bracket, shorted to ground
Internal short from the sensor return to the housing
Faulty bias supply in the engine control module

Symptoms

  • Check engine light
  • Bank 2 downstream reading cannot show lean values
  • Readiness for catalyst and oxygen sensor monitors stays open

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

P22BFP22C1P22B3P2255P2252

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