GM Service Manual Online
For 1990-2009 cars only
Table 1: OnStar® Button Assembly
Table 2: OnStar® Microphone
Table 3: Vehicle Communication Unit (VCU)
Table 4: Vehicle Interface Unit (VIU) - C1
Table 5: Vehicle Interface Unit (VIU) - C2

OnStar® Button Assembly


Object Number: 62439  Size: CH

Connector Part Information

    • 12047886
    • 8-Way F Metri-Pack 150 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A

LT GRN/BLK

2515

Keypad Supply Voltage

B

DK GRN/

WHT

2514

Keypad Signal

C-D

--

--

Not Used

E

ORN/BLK

2518

Keypad Low Reference

F

YEL/BLK

2516

Keypad Green LED Signal

G

BRN/WHT

2517

Keypad Red LED Signal

H

--

--

Not Used

OnStar® Microphone


Object Number: 35441  Size: CH

Connector Part Information

    • 12047663
    • 2-Way M Metri-Pack 150 Series (BLK)

Pin

Wire Color

Circuit No.

Function

A

BARE

1705

Drain Wire

B

GRY

655

Cellular Telephone Microphone Signal

Vehicle Communication Unit (VCU)


Object Number: 585586  Size: CH

Connector Part Information

    • 12059028
    • 25 Way F (BLK)

Pin

Wire Color

Circuit No.

Function

1

DK GRN/

WHT

2507

Audio Transmit Signal

2

--

--

Not Used

3

GRY

2520

Transceiver Low Reference

4

ORN

2240

Battery Positive Voltage

5

PPL/WHT

2513

Ignition ON Signal

6

BRN/WHT

2506

Audio Return Signal

7-10

--

--

Not Used

11

LT BLU/BLK

2512

OnStar Serial Data (+)

12

DK BLU/

WHT

2511

OnStar Serial Data (-)

13

--

--

Not Used

14

BARE

1792

Drain Wire

15

GRY/BLK

2508

Microphone Signal

16-17

--

--

Not Used

18

TAN/BLK

2510

OnStar Serial Data Return

19-23

--

--

Not Used

24

LT BLU

1235

Audio Low Reference

25

--

--

Not Used

Vehicle Interface Unit (VIU) - C1


Object Number: 258912  Size: CH

Connector Part Information

    • 12110113
    • 32-Way F Micro-Pack 100 Series (RED)

Pin

Wire Color

Circuit No.

Function

A1

--

--

Not Used

A2

GRY

2289

Rear HVAC/Audio Class 2 Serial Data

A3-A5

--

--

Not Used

A6

BLK/WHT

372

Remote Radio Audio Output (-)

A7

--

--

Not Used

A8

BRN/WHT

367

Remote Radio Left Audio Signal

A9

BARE

814

Drain Wire

A10

LT BLU

1235

Audio Low Reference

A11

BRN

2506

Audio Return Signal

A12

DK GRN

2507

Audio Transmit Signal

A13

BARE

1792

Drain Wire

A14

GRY/BLK

2508

Microphone Signal

A15

--

--

Not Used

A16

ORN

2240

Battery Positive Voltage

B1-B8

--

--

Not Used

B9

GRY

655

Cellular Telephone Microphone Signal

B10

BARE

1705

Drain Wire

B11

TAN

2510

OnStar Serial Data Return

B12

DK BLU

2511

OnStar Serial Data (-)

B13

LT BLU

2512

OnStar Serial Data (+)

B14

GRY

2520

Transceiver Low Reference

B15

PPL

2513

Ignition ON Signal

B16

--

--

Not Used

Vehicle Interface Unit (VIU) - C2


Object Number: 73222  Size: CH

Connector Part Information

    • 12110115
    • 32-Way F Micro-Pack 100 Series (BLU)

Pin

Wire Color

Circuit No.

Function

E1-E3

--

--

Not Used

E4

DK GRN/WHT

2514

Keypad Signal

E5

YEL/BLK

2516

Keypad Green LED Signal

E6

LT GRN/BLK

2515

Keypad Supply Voltage

E7-E15

--

--

Not Used

E16

ORN

2740

Battery Positive Voltage

F1

BLK

1550

Ground

F2-F3

--

--

Not Used

F4

ORN/BLK

2518

Keypad Low Reference

F5-F8

--

--

Not Used

F9

BRN/WHT

2517

Keypad Red LED Signal

F10-F16

--

--

Not Used