Powertrain, generic · Fuel and air metering

P0144 O2 Sensor Circuit High Voltage Bank 1 Sensor 3

Check engine lightOn
EmissionsRelevant
Drive cycleRequired
Limp modeNo

Sensor 3 is a third oxygen sensor on bank 1, behind a second converter or converter brick. It only exists on some vehicles – documented for Jaguar Land Rover's 3.0 V6 supercharged (2013–2016, where sensor 2 is 'mid-cat' and sensor 3 'post-cat') and Ford systems that monitor part of the converter volume. P0144 means the signal of sensor 3 stays above its upper limit, usually because the heater supply or another voltage reaches the signal wire. Ford's over-voltage test (above 1.1 V for 10 s, after 90 s of heating) explicitly covers downstream sensors 2 and 3; Jaguar Land Rover lists the code for its post-cat sensor. When it fails, the control module stops the downstream trim and cannot evaluate the converter; there is no limp mode.

Likely causes

Signal wire shorted to heater supply or battery voltage
Sensor faulty internally (heater-to-signal short)
Signal circuit open or high-resistance (GM bias logic)

Symptoms

  • Check engine light on (usually after two drive cycles)
  • Catalyst monitor readiness not set
  • Usually no noticeable change in driving

Repair estimate

DifficultyEasyDIY possible
Parts and labour€60–250
Time0.2–1 h

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

Parts involved

oxygen sensor bank1 sensor3oxygen sensor wiringcatalytic converter

Related codes

P0143P0142P0147P0138P0164

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