Mike's Workshop Manuals: Service manuals for every vehicle
Home >> Buick >> 2003 >> Century Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls Self-Diagnostics - 3.1L Engine >> Diagnostic Tests >> DTC P0140: Ho2S 2 Circuit - Insufficient Activity >> Test Description

Test Description

The numbers below refer to the step numbers in the diagnostic procedure.

  1. 2  - A normally functioning HO2S 2 voltage signal will fluctuate above and below the bias voltage amount. The action in the test step should result in a visible reaction from the HO2S 2 output.
  2. 4  - A voltage reading other than the specified amount in this step indicates an open circuit condition in one of the signal circuits or the PCM.
  3. 5  - This step inspects for an open circuit condition in the signal circuits, independent of the PCM.
  4. 7  - The conditions listed in the test may contribute to the failure of the HO2S. The conditions listed apply only to this type of failure.

scientia non olet · About Mike's Workshop Manuals