Test Description

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 numbers below refer to the step numbers on the diagnostic table.

2) - This step tests for blower motor operation in the off setting.
3) - This step test for blower motor operation in any speed setting.
4) - This step test for proper blower motor speed in each setting.
5) - This step test for proper operation of the recirculation actuator.
8) - This step checks for an internal fault in the HVAC control module.
10) - This step checks for any physical and mechanical problems.

Fig 1: Air Delivery Improper Diagnosis (Steps 1-8)

Courtesy of GENERAL MOTORS CORP.

Fig 2: Air Delivery Improper Diagnosis (Steps 9-12)

Courtesy of GENERAL MOTORS CORP.