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.

The range fault can only be detected following a recalibration. The recalibration can only be initiated by removing the battery positive voltage circuit to the HVAC control module.
The calibration limit is 64-216 counts. An actual range below this limit suggests an obstruction, something stuck in the door which limits travel. An actual range above this limit suggests an excessive travel condition, damaged, or missing foam seals.
A damaged mode door or a damaged actuator can cause this DTC to set.
An intermittent short to ground on the HVAC class 2 serial data circuit can set this DTC. Recalibrate actuators and test system.
If the condition is not present, refer to TESTING FOR INTERMITTENT & POOR CONNECTIONS .

Fig 1: DTC B3761 Diagnosis (Steps 1-3)

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC B3761 Diagnosis (Steps 4-11)

Courtesy of GENERAL MOTORS CORP.

Fig 3: DTC B3761 Diagnosis (Steps 12-13)

Courtesy of GENERAL MOTORS CORP.