Circuit/System Verification

WARNING: This page is about a different car, the 2010 GMC Sierra, 2010 GMC Cab & Chassis Sierra, and 2010 Chevrolet Silverado. However, it is still accessible from the selected car via links, so may be relevant.

Observe the DTC information with a scan tool. Verify there are no B52 HO2S heater or fuel trim DTCs set.
- If any DTCs are set, refer to Diagnostic Trouble Code (DTC) List - Vehicle .
Engine idling at operating temperature, observe the appropriate B52 HO2S parameter with a scan tool. Verify the following:
- The B52 HO2S 1 value should vary from below 200 mV to above 800 mV and respond to fueling changes.
- The B52 HO2S 2 value should change greater than 200 mV when the throttle is quickly cycled 3 times from closed to wide open and back to closed after running the engine at 1,500 RPM for 30 s.
Operate the vehicle within the Conditions for Running the DTC to verify the DTC does not reset. You may also operate the vehicle within the conditions that you observed from the Freeze Frame/Failure Records data.