GMC Chevrolet Silverado 2500HD 2021 Owner's Manual page 7

6 Introduction
23. Data Link Connector (DLC) (Out of View).
See Malfunction Indicator Lamp (Check
Engine Light) 0 111.
24. Electric Parking Brake 0 240.
25. Fog Lamps 0 138 (If Equipped).
Instrument Panel Illumination Control
0 140.
Exterior Cargo Lamps 0 139.
Exterior Lamp Controls 0 134.
Task Lighting 0 139 (If Equipped).