Powertrain, generic (extended)

P22C1 O2 Sensor Negative Current Control Circuit High (Bank 2 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P22C1 covers a return line (virtual ground) reading too high on the bank 2 post-catalyst wide-band probe: the line is pushed above the mid-level bias the controller sets, which in practice means contact with the heater supply or battery voltage, often via a melted or wet connector. With the reference raised, the rich side of the scale is lost and the oxygen value becomes useless. No maker documents this code publicly. Mitsubishi names the bank 1 front analog P2253 as a two-trip code on the 2022 Outlander, and Ford's front-probe logic books shorts to battery on any Bosch pin as P0152 for bank 2. CARB expects out-of-range detection on secondary sensors. P22BF is the open, P22C0 the low case, P22B4 bank 1. The lamp lights; the engine runs on.

Likely causes

Return wire touching the heater feed or another positive supply
Heat-damaged or wet connector bridging the return to a live pin
Internal leakage from heater to sensing cells inside the probe

Symptoms

  • Check engine light
  • Bank 2 downstream reading stuck high or implausible

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

P22BFP22C0P22B4P2256P2253

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