2005 Chevy Tahoe R/S Tip

Hi,

Just finished an '05 Chevy Tahoe. This baby was loaded to the hilt and even had the factory nav radio in the dash. The problem I encountered was the gauges, radio, and drl would pulse on and off once the vehicle started. Well I decided to power up the brown lead as accessory. That did the trick. In the past this wire was not necessary but, it looks like in some of the new vehicles it is. Another thing strange was the DB-DLM-3 from Omega would not always shut down the RAP system leaving the radio on. I ended up going into the door and to the grey/black door pin wire on the DDLM to shut it down manually. I did make Omega aware of this and they are going to investigate. It seems that now we may have to develop a digital code reader to read the buss systems in these vehicles so we can have a clue of what is going on.

Jon
Traveling Electronics

I have yet to find any logic or pattern behind the brown wire on GM's. You can do 50 of them and the brown wire may need to be fired up 2 or 3 times. Doesn't seem to matter what car, year, etc it is completely random from what I've seen. By the way, I've done an 05 Tahoe w/ nav as well and didn't fire up the brown wire, no problems. I have noticed on the newer GM's the radio still comes on when you don't fire up the brown wire, so I'm not sure what all it's powering nowadays. Anyone else with any info feel free to enlighten me.

Mike

In the newer GM vehicles the brown wire powers up accessories, but not the radio anymore. The Body Control Module senses the ignition turning on and it sends a data message to the radio to tell it to turn on. The radio will turn off when the BCM tells it to. The BCM must see the ignition turned off and a door opened to tell the radio to turn off. Depending on the vehicle and it's options/engine you may or may not have to power up the brown wire. It powers up some critical modules for anti-theft, engine or transmission at times.
Now you know, NowYaKnow.



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sparky

I am about to start an 04 Tahoe. I'm using Trilogix's GMDL-BP combo module. When you powered up the brown accessory wire, did you disconnect the orange accessory? If not, did you tie the brown and orange together into the R/S accessory? Thanks from an installer not familiar with GM vehicles.

Also, thanks for the tip! I'm sure you saved me some time.

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You can do it!

you never ever tie two vehicle wires together, the brown acc wire works differently than the orange, the orange only works in the ON position of the IGN switch where as the brown also adds the ACC position to what it does.

To date I've never had to energize the brown acc wire in any GM vehicle for remote start including 2005 Trucks

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Shaughn Murley
Install Manager, Dealer Services
Visions Electronics
Red Deer, Alberta

Extreme1, I agree on using only orange. However, do you think NismaX diode-isolated the connections?

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You can do it!

Hi,

No, I didn't use diodes or connect the wires together. I used a relay getting it's power (relay term 30) off the red ign harness lead. It follows the acc lead (term 86). Is hooked to the ground out when running lead from your remote starter (term 85) and finally hooked to the brown lead (term 87). I have never had to hook up a brown lead except in the Cavliers. Just never had the gauges do that to me before. I have done lots of other trucks and I do mean lots! My biggest customer is a Chevy dealer. Ahh things do change from time to time it just keeps us on our toes.

Jon
Traveling Electronics

Thanks, NismaX.

I'm tossing up this chart that I used to map my connections. Anyone see any problems before I start soldering?

Compustar 2wss-as

2004 Tahoe z71

Module: GMDL-BP (trilogix)

Harness

Pin

Wire Color

Wire Function

Pol

Wire

Color

Pol

Location

Wire

Color

Pol

CN1

1

Red

12V Constant

+

12V Constant

Red

+

Ignition Harness

12V Constant

Red

+

2

GREEN / WHITE

Parking Light

3

RED / White

12V Constant

+

12V Constant

RED / White

+

Ignition Harness

4

White

Accessory (blower motor)

+

Accessory

Orange

Ignition Harness

5

Violet

2nd Ignition

6

Yellow

Starter Output

Starter

Yellow

+

Ignition Harness

7

GREEN/ Red

Ignition

Ignition

Pink

+

Ignition Harness

8

Black

Ground

Chassis Ground

Chassis Ground

Black

CN2

1

GREEN / WHITE

Parking light output

-

Parking Lights

gray/black

-

BCM, brown plug, pin B2

2

Black

Status Out wire (gnd when running)

-

Gnd When Running

Brown

-

3

Green

Ignition Output

-

4

WHITE/ Black

Accessory Output

-

5

RED / Black

Starter Output

-

CN3

1

Light Blue

Parking Brake

-

2

Gray/Black

Hood Trigger

-

3

Light Blue/White

Foot Brake Shutdown

+

Brake Wire

White

Brake Pedal Switch

4

Violet/Black

Trunk Trigger Input

-

May require Trunk Pin from Tahoe to Compustar CN3 Pin 4. Module may do it though

5

RED / White

Door Trigger Input

-

Door Trigger Output

Pink/White

-

6

Red

Door Trigger Input

+

7

BROWN / Black

Glow Plug

-

8

BROWN / White

Glow Plug

+

9

Yellow/Black

Tach Input

ac

Tachometer

White

Instrument Cluster, Pin A5

CN4

1

N/A

2

Violet/White

Trunk Unlock

-

3

ORANGE / Black

Driver's Door Priority Unlock

-

4

Blue

Unlock Output

-

Unlock Input

Blue

-

5

Blue/Black

Lock Output

-

Lock Input

Green

-

6

N/A

Horn Trigger

BLACK / YELLOW to Black

-

BCM, gray plug, pin B9 or Column

Horn Input

Orange

-

ODBII (Pin #2)

Violet

Data Output

Violet

Dome Light Sup

Gray/Black

+

BCM, black plug, pin E

Dome Light Input

Pink

+

Please forgive me if I have violated forum ethics with this chart. I had no vicious intent. I tried a picture but couldn't keep it under 30 KB.

Any help is appreciated.

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You can do it!