P0140 – O2 Sensor Circuit No Activity Detected (Bank 2 Sensor 2)

Meaning:

When the PCM has perceived that second O2 sensor in bank 2 is inactive or open, the P0140 happens
The P0140 is triggered when the PCM has perceived that second O2 sensor in bank 2 is inactive or open

The PCM has perceived that second O2 sensor in bank 2 is inactive or open because it has not warmed up after more than 1 minute of the engine running.

Main Symptoms:

Possible Causes:

  • Faulty O2 sensor
  • Short, open or broken wire in O2 sensor circuit
  • Exhaust leak
  • Defective heater circuit in O2 sensor
  • Heater circuit has blown fuse
  • PCM is defective (least likely but not unlikely)

Diagnostic Steps:

  • Visually inspect all wiring to second O2 sensor (in bank 2) for loose, open or short connections
  • Use a wiggle test to determine where the voltage drops out
  • Visually check for exhaust leaks or air inlet leaks

Read More: OBD2 Codes List: Meaning, Fixes, and Free Download