Diagnostic Aids
WARNING: This page is about a different car, the 2017 Chevrolet Suburban 3500 HD. However, it is still accessible from the selected car via links, so may be relevant.
This ECM uses a bias voltage on the high and low signal circuits of the HO2S. The voltage measured between the high and low signal HO2S terminals is approximately 1, 900 mV. The voltage measured between the low signal HO2S terminal and ground varies based on the temperature of the HO2S and will typically be between 0 and 1, 000 mV, under normal operating conditions. The value of the high signal circuit when measured to ground will be approximately equal to the voltage measured between ground and the low signal circuit plus 1, 900 mV.