Diagnostic Test

Turn the ignition off.

Visually inspect the spoiler for any obstructions (ice, etc.).

Were any obstructions found? 

No 

1. Replace the Body Control Module. (Refer to ELECTRICAL/ELECTRONIC CONTROL MODULES/BODY CONTROL/CENTRAL TIMER MODULE - REMOVAL) .
2. Perform BODY VERIFICATION TEST .

Yes 

1. Repair the cause of the obstruction.
2. Perform BODY VERIFICATION TEST .