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Home >> Pontiac >> 2000 >> Firebird Base, 2D Convertible, Standard >> Repair and Diagnosis >> External Pages >> Different variant/trim >> Section 1 (Engine Control System Self-Diagnostics - 5.7L) >> Diagnostic Tests >> DTC P1153: Ho2S Insufficient Switching - Bank 2, Sensor 1 >> Circuit Description
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Circuit Description

WARNING: This page is about a different variant/trim than selected.

PCM monitors Heated Oxygen Sensor (HO2S) activity for 100 seconds. During this period, PCM counts number of times that HO2S switches from rich-to-lean and lean-to-rich. When PCM determines that HO2S does not switch enough times, DTC will set.

A lean-to-rich switch is determined when HO2S voltages changes from less than 300 mV to greater than 600 mV. A rich-to-lean switch is determined when HO2S voltage changes greater than 600 mV to less than 300 mV. DTC will set when PCM determines that within 100 seconds, the HO2S lean-to-rich and rich-to-lean switches are less than 10.