Onstar Brain Location?

[24v]

Does anyone know where this is? I am trying to find it so I can get a look at the antenna lead. I am about to install an avic-d3 into the truck, and would like to utilize the factory "sharkfin" for the satelittle raio, and the GPS. I have the satellite radio part figured out, just need to find the gps end so I can see what needs to be done to adapt it.

[jrrod2004]

yeah the VCIM (Vehicle Communication Interface Module) is located in the dash, here is some additional information:

 

(None of the hyperlinks will work)

 

 

Service Information

 

2008 Chevrolet Silverado - 2WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 1838160 Communication Interface Module Replacement (with RPO SLT)

 

Callout

 

Component Name

 

 

Preliminary Procedure

1. Remove the instrument panel accessory trim plate. Refer to Instrument Panel Accessory Trim Plate Replacement.
   
2. Remove the HVAC control module. Refer to HVAC Control Module Replacement or HVAC Control Module Replacement.
   
3. Remove the radio. Refer to Radio Replacement.
   

1

 

Communication Interface Module

 

Tip

 

 

• Push outward on the 2 tabs to release the communication interface module from the bracket.

 

 

• Disconnect the electrical connectors.

 

 

• Reprogram the communication interface module after replacement. Refer to

Control Module References.

 

 

• When replacing the communication interface module be sure to transfer Bluetooth Antenna, if equipped.

 

© 2008 General Motors Corporation. All rights reserved.

[jrrod2004]

And this is how you get to it:

 

 

Service Information

 

2008 Chevrolet Silverado - 2WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 1833054 Instrument Panel Accessory Trim Plate Replacement (with RPO SLT)

 

Callout

 

Component Name

 

1

 

Instrument Panel Accessory Trim Plate

 

Tip

Use a flat-bladed plastic trim tool in order to release the retainer clips securing the trim plate to the instrument panel.

 

2

 

Retainer Clips (Qty: 9)

 

© 2008 General Motors Corporation. All rights reserved.

[jrrod2004]

Service Information

 

2008 Chevrolet Silverado - 2WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 1740958 HVAC Control Module Replacement

 

Callout

 

Component Name

 

 

Preliminary Procedure

1. Remove the instrument panel accessory trim plate. Refer to Instrument Panel Accessory Trim Plate Replacement .
   
2. Remove the accessory switch assembly. Refer to Accessory Switch Replacement .
   
3. Disconnect the electrical connectors.
   

1

 

Screw, Control Assembly - Heater and Air Conditioning (Qty: 2)

 

Notice: Refer to Fastener Notice in the Preface section.

 

Tighten

1.5 N·m (13 lb in)

 

2

 

Control Assembly, Heater and Air Conditioning

 

Tip

HVAC Control Module must be reprogrammed. Refer to Control Module References .

 

© 2008 General Motors Corporation. All rights reserved.

[jrrod2004]

Service Information

 

2008 Chevrolet Silverado - 2WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 1838423 Radio Replacement (with RPO SLT)

 

Callout

 

Component Name

 

 

Preliminary Procedures

1. Remove the accessory switch assembly. Refer to Accessory Switch Replacement .
   
2. Remove the HVAC control module. Refer to HVAC Control Module Replacement or HVAC Control Module Replacement .
   

1

 

Radio Screw (Qty: 4)

 

Notice: Refer to Fastener Notice in the Preface section.

 

Tighten

2 N·m (18 lb in)

 

2

 

Radio Assembly

 

Tip

 

 

• Use a scan tool to retrieve the radio part number before removing the radio from the vehicle.

 

 

• Disconnect the electrical connector.

 

 

• Disconnect the antenna cable.

 

 

• Reprogram the radio after replacement. Refer to

Control Module References .

 

© 2008 General Motors Corporation. All rights reserved.

[jrrod2004]

as you can see, it sits behind the HVAC and under the radio (For the trucks containing the RRO LTZ, SLT only), problem is, this is a restricted part, and I cannot find any information containing connection views for the VCIM (But I will continue to look)

[24v]

Thanks for the help, I don't have that dash though. I will see what I can figure out. Hopefullyit is still in the same spot.

[jrrod2004]

so I am assuming that you have the SL, SLE/LS, LT trim truck????

[jrrod2004]

Here are the connectors for the VCIM,

 

 

Vehicle Communication Interface Module (VCIM) X1 (UE1)

 

 

 

Connector Part Information

 

• OEM: 15431362
  
• Service: 15306351
  
• Description: 16-Way F Micro 100A (WH)
  

 

Terminal Part Information

 

• Pins: 1-3, 6-7, 10-12, 15
  
• Terminal/Tray: 15445905/23
  
• Core/Insulation Crimp: J/J
  
• Release Tool/Test Probe: 12180559/J-35616-6 (BN)
  

 

Vehicle Communication Interface Module (VCIM) X1 (UE1)

Pin

 

Wire

 

Circuit

 

Function

 

1

 

0.35 D-GN

 

5060

 

Low Speed GMLAN Serial Data

 

2

 

0.35 BN/WH

 

2517

 

Keypad Red LED Signal

 

3

 

0.35 YE/BK

 

2516

 

Keypad Green LED Signal

 

4-5

 

--

 

--

 

Not Used

 

6

 

0.35 L-GN/BK

 

2515

 

Keypad Supply Voltage

 

7

 

0.5 BK

 

2550

 

Ground

 

8-9

 

--

 

--

 

Not Used

 

10

 

0.5 TN/BK

 

2500

 

High Speed GMLAN Serial Data Bus+

 

11

 

0.35 D-GN/WH

 

2514

 

Keypad Signal

 

12

 

0.5 TN

 

2501

 

High Speed GMLAN Serial Data Bus-

 

13-14

 

--

 

--

 

Not Used

 

15

 

0.5 RD/WH

 

3240

 

Battery Positive Voltage (except Y91)

 

0.5 RD/WH

 

1540

 

Battery Positive Voltage (Y91)

 

16

 

--

 

--

 

Not Used

 

Vehicle Communication Interface Module (VCIM) X2 (UE1)

 

 

 

Connector Part Information

 

• OEM: 15431365
  
• Service: 88952886
  
• Description: 12-Way F Micro 64 (WH)
  

 

Terminal Part Information

 

• Terminal/Tray: 15445905/23
  
• Core/Insulation Crimp: J/J
  
• Release Tool/Test Probe: 12180559/J-35616-6 (BN)
  

 

Vehicle Communication Interface Module (VCIM) X2 (UE1)

Pin

 

Wire

 

Circuit

 

Function

 

1

 

0.35 D-BU

 

658

 

Cellular Telephone Voice Signal

 

2

 

0.35 L-BU/BK

 

659

 

Low Reference

 

3

 

0.5 TN/BK

 

2500

 

High Speed GMLAN Serial Data Bus+

 

4

 

0.5 TN

 

2501

 

High Speed GMLAN Serial Data Bus-

 

5-7

 

--

 

--

 

Not Used

 

8

 

0.5 BARE

 

1782

 

Drain Wire (except Y91)

 

0.35 BARE

 

1782

 

Drain Wire (Y91)

 

9

 

0.35 GY

 

655

 

Cellular Telephone Voice Signal

 

10

 

0.5 BARE

 

514

 

Drain Wire (except Y91)

 

0.35 BARE

 

514

 

Drain Wire (Y91)

 

11-12

 

--

 

--

 

Not Used

 

Vehicle Communication Interface Module (VCIM) X3 (UE1 with U3U/UVB)

 

 

 

Connector Part Information

 

• OEM: 15431359
  
• Service: See Catalog
  
• Description: 16-Way F Micro 100A (GY)
  

 

Terminal Part Information

 

• Pins: 2, 4-5
  
• Terminal/Tray: 15445905/23
  
• Core/Insulation Crimp: J/J
  
• Release Tool/Test Probe: 12180559/J-35616-6 (BN)
  

 

Vehicle Communication Interface Module (VCIM) X3 (UE1 with U3U/UVB)

Pin

 

Wire

 

Circuit

 

Function

 

1

 

--

 

--

 

Not Used

 

2

 

0.35 PK

 

5149

 

Voice Recognition Audio Signal

 

3

 

--

 

--

 

Not Used

 

4

 

0.35 PK/BK

 

5152

 

Low Reference

 

5

 

0.5 BARE

 

1792

 

Drain Wire (except Y91)

 

0.35 BARE

 

1792

 

Drain Wire (Y91)

 

6-16

 

--

 

--

 

Not Used

[jrrod2004]

Looks like for the "pure pickup" dash, it is in the same vicinity.

 

 

 

Service Information

 

2008 Chevrolet Silverado - 2WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 1838157 Communication Interface Module Replacement (without RPO SLT)

 

Callout

 

Component Name

 

 

Preliminary Procedure

Remove the instrument panel lower center panel. Refer to Instrument Panel Lower Center Trim Replacement.

 

1

 

Communication Interface Module

 

Tip

 

 

• Push outward on the tab to release the communication interface module from the bracket.

 

 

• Disconnect the electrical connectors.

 

 

• Reprogram the communication interface module after replacement. Refer to

Control Module References.

 

 

• If replacing the communication interface module be sure to transfer Bluetooth Antenna, if equipped.

 

© 2008 General Motors Corporation. All rights reserved.

[jrrod2004]

Service Information

 

2008 Chevrolet Silverado - 2WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 1828891 Instrument Panel Lower Center Trim Replacement

 

Callout

 

Component Name

 

 

Preliminary Procedure

Remove the knee bolster assembly. Refer to Knee Bolster Replacement .

 

1

 

Instrument Panel Lower Center Trim Panel Screw (Qty: 2)

 

Notice: Refer to Fastener Notice in the Preface section.

 

Tighten

2 N·m (18 lb in)

 

2

 

Instrument Panel Lower Center Trim Panel Assembly

 

3

 

Retainer Clip (Qty: 6)

 

© 2008 General Motors Corporation. All rights reserved.

[jrrod2004]

Service Information

 

2008 Chevrolet Silverado - 2WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 1828882 Knee Bolster Replacement (without RPO SLT)

 

Callout

 

Component Name

 

 

Preliminary Procedure

Remove the park brake release handle assembly from the knee bolster. Refer to Parking Brake Release Handle Assembly Replacement .

 

1

 

Instrument Panel Left Outer Trim Cover

 

Refer to Instrument Panel Outer Trim Cover Replacement .

 

2

 

Knee Bolster Screw (Qty: 2)

 

Notice: Refer to Fastener Notice in the Preface section.

 

Tighten

2 N·m (18 lb in)

 

3

 

Knee Bolster Assembly

 

Tip

 

1. Disconnect the electrical connectors.
   
2. If replacing the knee bolster assembly, transfer all necessary components.
   

4

 

Retainer Clip (Qty: 3)

 

© 2008 General Motors Corporation. All rights reserved.

[jrrod2004]

Service Information

 

2008 Chevrolet Silverado - 2WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 1688547 Parking Brake Release Handle Assembly Replacement

 

Callout

 

Component Name

 

1

 

Park Brake Release Handle Bolt (Qty: 1)

 

Notice: Refer to Fastener Notice in the Preface section.

 

Tighten

9 N·m (80 lb in)

 

2

 

Park Brake Release Handle Cable

 

Tip

Slide the park brake release cable forward to remove it from the park brake module.

 

3

 

Park Brake Release Handle

 

© 2008 General Motors Corporation. All rights reserved.

[24v]

Yes, I have the LT1. Also, I do not see the antenna connection on those diagrams.

[jrrod2004]

That is because the antenna connection is not included, that has to be hunted down in a different section