DTC P0134 & P0154: Ho2S Circuit - Insufficient Activity - Bank 1 & 2, Sensor 1: Description

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The Powertrain Control Module (PCM) supplies a voltage of about 450 mV between the Heated Oxygen Sensor (HO2S) high and low signal circuits. The oxygen sensor varies the voltage over a range from about 1,000 mV when the exhaust is rich, down through about 10 mV when the exhaust is lean. The PCM monitors and stores the HO2S voltage information. The PCM evaluates the HO2S voltage samples in order to determine the amount of time the HO2S voltage was out of range. The PCM compares the stored HO2S voltage samples taken within each sample period and determines if the majority of the samples are out of the operating range. The PCM monitors the HO2S voltage and detects if the voltage goes out of the bias range. If the PCM does not detect the voltage went out of the bias range, a Diagnostic Trouble Code (DTC) sets.