Powertrain, generic (extended)

P2234 O2 Sensor Signal Circuit Shorted to Heater Circuit (Bank 2 Sensor 1)

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2234 means the heater of the front air-fuel sensor on bank 2 couples into its measuring circuit. On a wide-band sensor the disturbance is small, so the check is finer than on rear sensors. GM's 2005 tables for the Bosch-equipped 2.8/3.6 V6 look for a signal step of 0.08-0.2 V appearing no later than 0.05 s after each heater switching edge; 18 such steps in a 10 s window count as a failure, the sensor must have been fully hot for 10 s, and the MIL follows after two trips. Jaguar Land Rover lists P2234 among the bank 2 front-sensor codes of the 2014-2016 LR4, Range Rover and Range Rover Sport 3.0 V6 and blames thermal shock from water hitting the hot element; the sensor is replaced. P2231 is the same fault on bank 1. Closed-loop fuelling on bank 2 may drop out.

Likely causes

Front sensor element cracked by thermal shock (water on the hot sensor)
Heater and signal wires of the bank 2 sensor touching in the harness
Moisture in the sensor connector bridging heater and signal pins

Symptoms

  • Check engine light
  • Higher fuel consumption when bank 2 runs without lambda control
  • Other bank 2 front-sensor codes stored at the same time

Repair estimate

DifficultyMediumDIY possible
Parts and labour€90–380
Time0.5–2 h

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

Parts involved

oxygen sensor bank2 sensor1oxygen sensor heateroxygen sensor wiring

Related codes

P2231P2235P2240P0050P0150

References: gsi.ext.gm.com, static.nhtsa.gov, law.cornell.edu.