GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 GMC_Truck 🢒 2009 🢒 TopKick C-Series (Conventional) C6/C7/C8 🢒 Diagnostic Navigation 🢒 Vehicle Diagnostic Information 🢒 Data Communication Schematics
Figure 1:

Data Link Connector Power and Ground
Object Number: 2076371 Size: FS
Figure 2:

Splice Pack SP203
Object Number: 2076372 Size: FS
Figure 3:

High Speed GMLAN
Object Number: 2076374 Size: FS
Figure 4:

CAN Connector Power and Ground - L18 w/JE4, LF6, LF8
Object Number: 2076377 Size: FS
Figure 5:

Serial Data Gateway (SDG) - L18 w/JE4, LF6, LF8
Object Number: 2076378 Size: FS
Figure 6:

J1939 Serial Data, 1 of 2 - L18 w/JE4, LF6, LF8
Object Number: 2076379 Size: FS
Figure 7:

J1939 Serial Data, 2 of 2 - L18 w/JE4, LF6, LF8
Object Number: 2076380 Size: FS