Hummer H2 For those who like a little more gleam to their Hummer, the H2 offers a similar rugged look as the H1, but as a lower cost, and with more added features, making it almost a massive luxury SUV.

Brake problems?

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Old Feb 19, 2026 | 11:09 PM
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Lambo's Limo's Avatar
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Angry Brake problems?

Hi all, I have checked threads but haven't come across any problem that is similar to mine.
I recently purchased my first H2 ( dreamed of owning one for a very long time ) and now having issues when braking on ice or slippery conditions. When I brake, the wheels immediately lock up ( no ABS ) and I get the message on the dash " Service Brake System " along with a red brake symbol. The H2 drives normal during this, just doesn't have ABS. AND the transfer case seems to be locked and I only have rear wheel drive ( great for drifting and donuts ).
You can turn off the ignition and fire it back up and the red brake light symbol disappears as well as "service brake system" only to reappear when you lock up the brakes.
I know it's a big ask, but I was wondering if anyone else has come across this or know where I can start? I thought I'd start by checking the transfer case motor as I see that is a H2 issue. And maybe check the speed sensors? Just waiting for temps to warm a bit as I'll be working on it in the driveway as it's too tall fit through my garage door.
Appreciate any info or direction.
 
Old Feb 19, 2026 | 11:16 PM
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Sorry, forgot to mention it's a 2004 H2 with just under 300K and I don't know the history of it as I bought it at an auction.
 
Old Feb 20, 2026 | 10:14 AM
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Welcome to HF.

MOVED to the H2 Section, where................ All H2 Tech Questions go.

Get a good quality bidirectional Scanner that can read your ABS Codes and post them here so that we can help you "service" the brake system.

 
Old Feb 20, 2026 | 08:07 PM
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The only thing I can offer is to buy a cheapy code reader which should plug into your OBD II port below the steering wheel. If there are any codes that would lead you to the problem by the code number read out which you can plug into google and see what it means.

Your other Option is I think Auto Zone which will read the code for free. As for me..That would be the first step. Usually when the transfer case is not working it could mean a few things. The internal motor..or the Switch that controls it thu one of the computers or the computer that controls the transfer case.

Hang in there we have some smart people here that will come on and try to help you. It may not be right away but keep watching your thread.
Not familiar with your year so I,m not much help other then the above.
 
Old Feb 21, 2026 | 01:26 PM
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Thanks guys, appreciate the time, I'll look at getting a hold of a code reader and go from there. I'll post my findings when/if I find something.
 
Old Feb 21, 2026 | 02:03 PM
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Originally Posted by Lambo's Limo
Thanks guys, appreciate the time, I'll look at getting a hold of a code reader and go from there. I'll post my findings when/if I find something.
That sounds Good. One thing I would mention is that when the guys here offer answers to problems from a Poster, It nice if the poster comes back on and follows thru and tells us what the problem was or what he is doing in regards to fixing as well as posting pics. Members sometimes spend time researching and posting diagrams and other things. This also helps other people that might have the same problem.

So they like to hear how you made out. Thanks and keep us posted.

Mark R
 
Old Feb 21, 2026 | 06:45 PM
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Did I read that right, only has a rear wheel drive working? And appears locked in 4 Hi?

 
Old Feb 22, 2026 | 12:11 AM
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Is your front driveshaft attached?
 
Old Feb 24, 2026 | 04:51 PM
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front drive shaft is attached. Still tracking down a code reader. I tried using the "Fixed" code reader but it couldn't find anything.
I'm currently shopping for my own reader as I plan on keeping my H2 for a long time. There's so many out there but trying to find one that works on older Hummers.
 
Old Feb 24, 2026 | 04:57 PM
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Yes, rear wheel drive and transfer case control is lit in 4 Hi.
 



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