Diagnostic Aids
WARNING: This page is about a different car, the 2009 Pontiac Torrent and 2009 Chevrolet Equinox. However, it is still accessible from the selected car via links, so may be relevant.
- The HO2S 2 voltage should be between 400-520 mV with the ignition ON. If the voltage is greater than the specified value, there is a condition with the HO2S circuits. If the voltage does not change after disconnecting the HO2S 2, the condition is between the sensor and the ECM. If the voltage is between 400-520 mV after disconnecting the sensor, the condition is with the HO2S 2.
- Inspect the HO2S harness connector for water intrusion. Moisture in a connector may cause voltage to bleed to other circuits within the connector.