Vehicle Communication Unit (VCU) Connector End View

Courtesy of GENERAL MOTORS CORP.
Connector Part Information		AMP 205207-1 25-Way F DB-25 (BLK)
Pin	Wire Color	Circuit No.	Function
1	DK GRN/WHT	965	Audio Transmit Signal
2	-	-	Not Used
3	GRY/BLK	1798	Low Reference
4	ORN	2240	Battery Positive Voltage
5	PPL/WHT	971	Ignition On Signal
6	BRN/WHT	964	Audio Return Signal
7-10	-	-	Not Used
11	LT BLU/BLK	970	Onstar Serial Data (+)
12	WHT	969	Onstar Serial Data (-)
13	-	-	Not Used
14	BARE	966	Drain Wire
15	GRY	967	Microphone Signal
16-17	-	-	Not Used
18	TAN/BLK	968	Onstar Serial Data Return
19-23	-	-	Not Used
24	DK BLU	981	Audio Low Reference
25	-	-	Not Used