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Service Information 2007 Chevrolet Silverado - 4WD | Sierra, Silverado (VIN C/K) Service Manual | Document ID: 2171546
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#08-08-42-003: Stop Lamps Intermittently Turn Off After Coming to a Complete Stop While Still Having Pressure on Brake Pedal (Replace Stop Lamp Switch) - (Jul 23, 2008)


Subject: Stop Lamps Intermittently Turn Off After Coming to a Complete Stop While Still Having Pressure on Brake Pedal (Replace Stop Lamp Switch)


Models: 2007-2008 Cadillac Escalade, Escalade ESV, Escalade EXT

2007-2008 Chevrolet Avalanche, Silverado, Suburban, Tahoe

2007-2008 GMC Sierra, Yukon, Yukon Denali, Yukon XL, Yukon Denali XL




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Condition:
Some customers may comment on the stop lamps turning off prior to the brake pedal reaching the fully released position. Some customers may also comment on the stop lamps turning off while having light pressure on the brake pedal.

Some customers with Integrated Trailer Brake Control (ITBC) may comment that the electronic trailer brakes disengage after the vehicle has come to a complete stop. This disengaging of the trailer brakes coincides with the stop lamps turning off.

Cause:
This condition may be caused by not enough pressure being applied to the stop lamp switch to keep the brake lights on.

Correction:
Technicians are to replace the stop lamp switch. The new stop lamp switch has a reduced internal spring apply force, which will allow the lamps to stay on with less applied brake force.

Refer to SI for Stop Lamp Switch replacement procedures.
Use the new Stop Lamp Switch, P/N 25991704.
Parts Information
Part Number - 25991704
Description - Switch,Stop Lamp
Qty - 1


Warranty Information
For vehicles repaired under warranty, use:

Labor Operation
Description
Labor Time

N2440
Switch, Stop Lamp - Replace
Use Published Labor Operation Time

GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the information.

WE SUPPORT VOLUNTARY TECHNICIAN CERTIFICATION


© 2008 General Motors Corporation. All rights reserved.

Some of you might have this problem on 99-07 classics too
 

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Re: TSB >> Service Information 2007 Chevrolet Silverado - 4WD | Sierra, Silverado (VI

I have noticed this before but didnt think nothing about it:shrug: good find JB. How long do you think it would take for them to install?
 

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2008 RCSB
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Re: TSB >> Service Information 2007 Chevrolet Silverado - 4WD | Sierra, Silverado (VI

I managed to get it figured out.. Inside of brake switch is a spring that controls the position of 3 sets of contacts (2 NC, 1 NO - I'm assuming the NO set is for the brake lights). The spring had too much pressure on it causing the NO set to open back up too soon, so shortening the spring (seems to have) fixed it. Instructions follow for anyone interested.

1. Get a new brake light switch in-case you break something.

2. Remove the brake light switch. Unplug the harness from it, remove the retaining clip, slide the assembly left, and voila! Install in reverse order *note that the booster rod goes between the open slot on the switch assembly*.

3. Open up the switch assembly - there are 5 clips that you have to push and the cover comes off.




4. Remove the spring (hold your hand over it or you get to watch it fly across the room).

5. Using lineman's pliers, cut a *very* short piece off of the spring (did I recommend eye protection?). You can always cut a little more off later if you don't get enough this time - I actually made 2 cuts.
(I cut this much, plus about 1/2 twist from mine)


6. Put the spring back in and make sure the contacts worked as before.

7. Reinstall switch assembly and test. Repeat as necessary.

Hope this helps someone in the future.
I just replaced mine to the new unit. Seems to be marginally better. I may tinker with the old one like several others have.

Wasn't too difficult to remove, I do have a few pointers if anyone else is able to find the new switch.
1. make sure you can open your door all the way, i didn't and my body was contorted trying to work under the dash.
2. flash light - use one, it helps. Not a 6 Cell mag-lite like I had (it was the closest to me).
3. Screw/bolt comes off brake pedal first. Clip needs to be opened up with flat head screwdriver (couldn't tell until I used flashlight).
4. REMEMBER HOW IT WAS ORIENTED. The hardest part of it all was trying to remember how the damn thing was placed in there.
5. Don't lose the retaining clip like I did, it shot straight upwards and ended up behind a module junction box on floor board.

Easily a 5 minute job.
I removed mine and took it apart and cut 2.5 coils off the spring of mine yesterday. My brakes now come on with just slight pressure and stay on with just the weight of my foot on the pedal.

The GMT900 looks different from the GMT800 pictured above, however its the same mechanical principle.
 

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2008 RCSB
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9,634 Posts
Discussion Starter · #4 ·
Re: TSB >> Service Information 2007 Chevrolet Silverado - 4WD | Sierra, Silverado (VI

I have noticed this before but didnt think nothing about it:shrug: good find JB. How long do you think it would take for them to install?
maybe 1 hour max, however some dealers are having a hard time getting parts due to this bankruptcy. Some people have had the new switch (has less tension on the spring) and it was better but still not perfect.

I took mine apart and fixed it myself.
 
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