GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2008 🢒 Savana 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Data Communication Schematics
Figure 1:

Low Speed GMLAN
Object Number: 1884068 Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
High Speed GMLAN (4.3L/4.8L/5.3L/6.0L)
Figure 2:

High Speed GMLAN 4.3L/4.8L/5.3L/6.0L
Object Number: 1884072 Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
High Speed GMLAN (6.6L)
Low Speed GMLAN
Figure 3:

High Speed GMLAN 6.6L
Object Number: 1925728 Size: FS
Master Electrical Component List
Data Link Communications Description and Operation
Control Module References
High Speed GMLAN (4.3L/4.8L/5.3L/6.0L)