Diagnostic Aids

WARNING: This page is about a different car, the 2002 GMC Sierra, 2002 GMC Cab & Chassis Sierra, 2002 Chevrolet Silverado, and 2002 Chevrolet Cab & Chassis Silverado. However, it is still accessible from the selected car via links, so may be relevant.

A dead zone exists in a range from 10 counts above the maximum mode door position to 10 counts below the minimum mode door position. When the mode door Actual Data parameter is within the dead zone, the DTC will not set. If the Commanded Data parameter differs from the Actual Data parameter by 54 counts or more outside the dead zone, the DTC will set.
A damaged or broken recirculation door or a damaged or broken actuator can cause this DTC to set.

Fig 1: DTC B0268 Diagnosis (Steps 1-5)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC B0268 Diagnosis (Steps 6-13)

Courtesy of GENERAL MOTORS CORP.