Powertrain, generic (extended)

P2239 O2 Sensor Positive Current Control Circuit High (Bank 1 Sensor 1)

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

P2239 is the high-side counterpart for the pump-current circuit of the bank 1 front wide-band sensor. On the Saab 9-5 2.0 turbo (2010) it sets when, in closed loop with the mixture deliberately enriched, the signal still sits at 1.48-1.51 V for 1 s, meaning the sensor ignores a change it should report; it is a Type B code. GM's 2005 V6 tables check a similar window (1.48-1.52 V while target lambda lies outside 0.97-1.03) under P2237. Mitsubishi's 2022 Outlander also lists P2239 as a two-trip code. Ford files this wire touching battery voltage under P0132 instead. A short to the heater supply can overload the sensor interface, so the wiring deserves a check before a new sensor goes in. P2238 is low, P2242 bank 2.

Likely causes

Pump-current wire shorted to heater supply or battery voltage
Wide-band sensor with internal short or stuck output
Damaged sensor interface in the ECM

Symptoms

  • Check engine light after two drives
  • Lambda reading frozen near 1.0 regardless of load
  • New sensor fails again quickly if the wiring short is not found

Repair estimate

DifficultyMediumDIY possible
Parts and labour€80–450
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

oxygen sensor bank1 sensor1oxygen sensor wiringecm

Related codes

P2237P2238P2242P0132

References: saabwisonline.com, gsi.ext.gm.com, static.nhtsa.gov, fordservicecontent.com.