2008 Tahoe Cruise Control

[2008TahoeOwner]

I just purchased my 2008 Tahoe towards the beginning of this year and, ever since I bought it, the cruise control has not worked very well. And, actually, it has not worked for a couple months, now. Is anyone else experiencing this same issue with the 2008 Tahoes? I guess it is almost four years old, so I'm sure it's due to be serviced if the first owner used it a lot. I was thinking that it might be a wire that came loose, but I cannot take apart the cover to the cruise control buttons to check it out. Would I need to take apart the whole steering wheel to get to the wires in the side compartments, or should they be able to be taken off independently? I tried to pry them to get them to come off, but they weren't giving so I stopped prying so I wouldn't damage anything.

 

[TahoeJo]

Hey man, I seriously doubt it's the buttons, but if you want to test them, you'll have to pull off the air bag which is pretty easy. On the side of the steering wheel there's a small hole on each side. You have to insert something a couple inches long and skinny enough, like a thin phillips screwdriver, and each side will pop out. You're pushing against a metal tab that you need to push in to release the "lock" on each side. I'm making it sound harder than it is hahahaha. Then you can remove each trim piece with the buttons to test them.
Tomorrow at work ill search for bulletins to see if there are any commons issues.

 

[2008TahoeOwner]

Thank you so much for the information, TahoeJo. I really appreciate your reply. I will definitely try to test my wires, now that I know how to get to them. :-D

I noticed, however, that my cruise control worked after I had to slam on my brakes about four days ago, but it stopped working again once I applied my brake (even to just touch my brake the slightest bit.) I'm thinking it's an issue more along the lines of the brake sensor for the cruise control. In the past, I thought I recognized (and, now, know that I recognized) a pattern with when it would work and when it would not...it would only work if I applied my brakes abruptly. If I tapped on my brakes to slow down or came to a normal stop, it would deactivate the cruise control (as it should,) but it would also keep it deactivated until I came to a more abrupt stop/slow down. But, as time went on, the cruise control would work less and less, causing me to (in the past couple of months) not be able to use it at all.

If I can't find the wiring messed up, I guess I will have to pay the deductible to have the dealership diagnose the true issue and repair it, since it is still under warranty. :-( I just wanted a cheaper option, if possible.

 

[ILoveMyHoe]

I have an 07, and when I'm going down the road every once in a while the cruise just shuts off. It doesn't do it a lot, but its weird.

 

[TahoeJo]

Checked bulletins today and here are a couple, but nothing really definative htat would make me suspect they would apply. After what you just said about how they worked when you'd make a hard stop but not when you make a normal stop I'm suspecting it's a loose/poor connection.
Do you have factory trailer brakes? There's a bulletin for cruise inop for models with factory trailer brake controllers. It's for an issue with the master cyl pressure sensor. It reads...
"Condition/Concern:


Some owners may comment of the cruise control being inoperative. The Trailer Brake Control Module (TBCM) may set a DTC B3894. If normal diagnostics do not lead to a correction, check the ″Master Cylinder Pressure″ sensor parameter listed in the TBCM data list. If it is displaying pressure with no brake pedal input, suspect a concern with the master cylinder pressure sensor, wiring/terminals, EBCM, ect. for HD models. On light duty models the master cylinder pressure sensor is internal to the BPMV/EBCM."

EBCM is the electronic brake control module, and BPMV is the brake pressure modulator valve...

When you push the button to on the left side of the steering wheel in the middle turn the cruise on and off, does it light up? Are there any there any other lights on , or issues? The more info you can give will make a difference.

My honest advice though since you have extended warranty is to wait until you have a few issues then bring it to the dealership. If you do that, then you'll only have to pay the deductible once for the multiple concerns. You don't have to pay the deductible per concern, unless you only have one.

 

[2008TahoeOwner]

I have an 07, and when I'm going down the road every once in a while the cruise just shuts off. It doesn't do it a lot, but its weird.

Hi, ILoveMyHoe.

I was experiencing this same thing with the cruise control shutting off while driving down the road, and I don't know why it's happening, either.

Is this the only weird thing that has happened to your Tahoe's cruise control?

 

[ILoveMyHoe]

Yep that's the only weird thing that has happened with cruise.

 

[2008TahoeOwner]

Checked bulletins today and here are a couple, but nothing really definative htat would make me suspect they would apply. After what you just said about how they worked when you'd make a hard stop but not when you make a normal stop I'm suspecting it's a loose/poor connection.
Do you have factory trailer brakes? There's a bulletin for cruise inop for models with factory trailer brake controllers. It's for an issue with the master cyl pressure sensor.

Thank you for checking into this further for me, TahoeJo. I really appreciate it! I'm not sure if my Tahoe has factory trailer brakes. Do you know how I would find out whether it does or does not? Also, what do I need to look at to try to see whether it's a loose/poor connection? Would it be something down where my brake pedal is inside my vehicle or would it be something under the hood? I'm really novice when it comes to maintenance, so I'm trying to learn as much as I can to be able to make things cheaper for myself in the long run. Any suggestions? The vehicle manual does not give any maintenance information regarding the cruise control, so I'm stuck there. :-(

When you push the button to on the left side of the steering wheel in the middle turn the cruise on and off, does it light up? Are there any there any other lights on , or issues? The more info you can give will make a difference.

When I push the button on my steering wheel to turn on the cruise control, the light does light up. And, there are no other lights that are lit up to inform me of any other concerns (except for the tire pressure light that lights up whenever it's colder outside, but this would not interfere with the cruise control working correctly [to my understanding, at least.])

My honest advice though since you have extended warranty is to wait until you have a few issues then bring it to the dealership. If you do that, then you'll only have to pay the deductible once for the multiple concerns. You don't have to pay the deductible per concern, unless you only have one.

I totally understanding about taking it in when I have multiple issues so I pay only one deductible fee for multiple issues rather than paying one deductible fee for each issue that I experience. My Tahoe seems to be holding up and doing very well maintenance-wise so far, so I'm not sure how soon another issue will occur to pay only one deductible for more than this one issue.

 

[pcaggie123]

I also have a 07' LTZ and have experienced the same problems that all of the posters have. It would work fine in the summertime when the weather was warm, but as the weather would turn cold it wouldn't work at all. Sometimes it would work all of the sudden and then I would hit a bump and it would turn off. After close observation of when it would work and not work, and the conditions at the time, I narrowed it down to the rear brake light controller which is mounted to the brake pedal. The controller is attached to the pedal with a pin that goes through the controller and a rod that comes from the firewall which I believe goes to the brake servo. As you apply the brakes, the rod depresses a micro switch in the brake controller which sends a signal to turn the rear brake lights on. But the controller is also tied into the cruise control. Over time and all the applying of the brakes, the micro switch in the controller becomes worn and doesn't open when you release the brake pedal, fooling the cruise control into thinking the brakes are applied and thus not allowing it to function. That is why the cruise control will work intermittently or not at all. It's a simple fix and requires no special tools. The controller is available from your local dealer and runs about $15+ tax. I've replaced mine and have had no further problems with the cruise control.

Good Luck!

 

[ILoveMyHoe]

Thanks a lot!

 

[2008TahoeOwner]

Thank you so much for your information, pcaggie123! I will definitely have the rear brake light controller. This sounds like it's definitely what is causing all of our issues with the cruise control working correctly (if at all.) I thought it might have something to do with a part that the brake pedal attaches to, but I had no idea how to diagnose it to find out whether or not the part (if I were to find it) was working correctly (without having to replace it first.) This seems like a quick fix for all of us!

Have a wonderful holiday season, Everybody! Stay safe, and watch out for idiots on the roads! :-D

 

[llllljrlllll]

Your cruise control brake light switch is bad, just replace it. Look at your brake pedal and follow it up, at the top, your gonna see the brake light switch, it is located on the side of the brake pedal and is retained by the same clip that retains the booster push rod. Unplug the electrical connector from the switch, remove the clip that retains the switch and pushrod to the pin on the brake pedal arm and slip the brake light switch off the pin, Installation is the reverse. Good luck

 

[gjohnon15]

I alos have an 07 and had the same problem last summer. Also have a trailer break controller that was intermittent. The fix was WD-40 on the break light switch cam. did not need to replace it and it has not had a problen for 6 months now.

 

[frankd]

Cruise Control Fix

My cruise control would not engage, light on wheel would illuminate. Read the posts above, replaced the brake light switch on the pedal, works like a champ. The part was less than $20 from the dealer, took 5 minutes to replace the part. Be careful when removing the clip, mine shot upward and it took me longer to find it than to do the rest of the R&R!

Thanks
Frank

 

[thedude337]

Checked bulletins today and here are a couple, but nothing really definative htat would make me suspect they would apply. After what you just said about how they worked when you'd make a hard stop but not when you make a normal stop I'm suspecting it's a loose/poor connection.
Do you have factory trailer brakes? There's a bulletin for cruise inop for models with factory trailer brake controllers. It's for an issue with the master cyl pressure sensor. It reads...
"Condition/Concern:


Some owners may comment of the cruise control being inoperative. The Trailer Brake Control Module (TBCM) may set a DTC B3894. If normal diagnostics do not lead to a correction, check the ″Master Cylinder Pressure″ sensor parameter listed in the TBCM data list. If it is displaying pressure with no brake pedal input, suspect a concern with the master cylinder pressure sensor, wiring/terminals, EBCM, ect. for HD models. On light duty models the master cylinder pressure sensor is internal to the BPMV/EBCM."

EBCM is the electronic brake control module, and BPMV is the brake pressure modulator valve...

When you push the button to on the left side of the steering wheel in the middle turn the cruise on and off, does it light up? Are there any there any other lights on , or issues? The more info you can give will make a difference.

My honest advice though since you have extended warranty is to wait until you have a few issues then bring it to the dealership. If you do that, then you'll only have to pay the deductible once for the multiple concerns. You don't have to pay the deductible per concern, unless you only have one.

my abs and e brake light come on all the time and only go off after you shut it off and start it again, and my cruise only works when im pulling my boat

 

[johnny_orange_727]

I also have a 07' LTZ and have experienced the same problems that all of the posters have. It would work fine in the summertime when the weather was warm, but as the weather would turn cold it wouldn't work at all. Sometimes it would work all of the sudden and then I would hit a bump and it would turn off. After close observation of when it would work and not work, and the conditions at the time, I narrowed it down to the rear brake light controller which is mounted to the brake pedal. The controller is attached to the pedal with a pin that goes through the controller and a rod that comes from the firewall which I believe goes to the brake servo. As you apply the brakes, the rod depresses a micro switch in the brake controller which sends a signal to turn the rear brake lights on. But the controller is also tied into the cruise control. Over time and all the applying of the brakes, the micro switch in the controller becomes worn and doesn't open when you release the brake pedal, fooling the cruise control into thinking the brakes are applied and thus not allowing it to function. That is why the cruise control will work intermittently or not at all. It's a simple fix and requires no special tools. The controller is available from your local dealer and runs about $15+ tax. I've replaced mine and have had no further problems with the cruise control.

Good Luck!

I bought a used 2008 LTZ and the cruise control was working intermittently. The cruise control light would turn on on the steering wheel, but when you would press set, nothing happened. I replaced the above mentioned micro switch, and PRESTO!!!! Cost me 18 bucks to fix. Part No. 25981009 (switch P189J1). The install was very easy! Thank u!!!!!! :happy160:

 

[cboshart]

My cruise control works intermittently and I thought I would try and replace the brake light switch. Where is it located? If I hit a bump it goes off. It only comes on 50% of the time.

 

[cboshart]

Can you send of pic of where it is located?

 

[Luis]

Having the same issue with mine now. Going to replace the BLS today...

 

[meatsweats]

I had this same problem. Cruise would work intermittently and sometimes not engage at all. The Brake Light Switch was narrowed down as the issue. I bought an ACDelco off Amazon and took 30-45 min replacing. Switch is located on the brake pedal and here is a good video that helped me:

https://www.youtube.com/watch?v=pHwWV98wBZU

Once done I patched things up it worked like a charm.

Note - to remove and replace the switch be careful when removing the smaller side(you'll see what I mean when you get the part) as the tabs are not very strong and can crack.