P1153 GMC - HO2S Insufficient Switching Bank 2 Sensor 1
- Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 harness is open or shorted
- Heated Oxygen Sensor (HO2S) Bank 2 Sensor 1 circuit poor electrical connection
The Powertrain Control Module (PCM) monitors the Heated Oxygen Sensor (HO2S) activity for 100 seconds. During this monitor period the PCM counts the number of times that the HO2S switches from rich to lean and lean to rich.
A lean to rich switch is determined when the HO2S voltage changes from less than 300 mV to greater than 600 mV. A rich to lean switch is determined when the HO2S voltage changes from more than 600 mV to less than 300 mV.
Any information is appreciated. Thanks