Powertrain, generic (extended)

P22B4 O2 Sensor Negative Current Control Circuit High (Bank 1 Sensor 2)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P22B4 is stored when the negative current control line (virtual ground) of the bank 1 downstream wide-band probe climbs above its intended bias. Because this return sits at a mid-level voltage rather than at chassis ground, a short to the heater feed or battery voltage is the classic trigger, sometimes via moisture or a heat-damaged connector. No maker documents this exact code publicly; Mitsubishi lists the upstream analog P2253 as a two-trip code for the 2022 Outlander, while Ford treats upstream shorts to power as P0132. CARB asks for detection of out-of-range values on such sensors. P22B2 is the open, P22B3 the low variant, P22C1 the bank 2 code. The lamp is on and the related emission monitors will not complete.

Likely causes

Return wire shorted to heater supply or battery voltage
Heat-damaged or wet connector bridging pins
Internal heater-to-cell leakage in the sensor

Symptoms

  • Check engine light
  • Downstream oxygen reading erratic or at a limit

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

P22B2P22B3P22C1P2253P22AD

References: static.nhtsa.gov, newtonnet.co.uk, bosch-motorsport.com, law.cornell.edu.