I have a H2 with a problem no one can seem to tell me the solution to. I keep it garaged now 90% of the time until I can figure out this issue. When I drive it about 5 miles or so(regular street driving) the dash lights up with just about all the warnings possible. The main warning is the braking system, as well as about all the other warnings possible. I was first told by the dealer it was the ECM(wrong!!) same issue exists. I have had the truck hooked up to autozone, advance and the dealers check engine light readers and all give different problems. HELP!! Has anyone experienced this issue, I am at my wits end and contemplating selling my beast.

 

I just went thru a similar problem and it was my ebcm. Just curious how did you rule that out? What other lights are coming on? Can you post a picture or list them? What error code(s) is the scanner showing?

 

H2 questions should go in the H2 section where other H2 owners can help.


I saw you posted a couple months back about water intrusion: "I was wondering if anyone has had problems with the running lights allowing water to enter into the roof area when it rains. I have tried several things to solve this problem and am wondering what it does take to stop the leakage."

Have you ever had enough water to get the area behind the dash wet?


Let's get some terms straight just for the sake of conversation in this thread, I think you guys are possibly on different pages? ebcm vs ecm.

A BCM is a body control module, they are mounted inside and DO NOT like water=moisure, hence they are inside. Th H2 is between the headlight control and the instrument cluster. Get that wet, and you will have a pack of Gremlins on board. They control body electrical in conjunction with some overlapping PCM features.

A PCM is a Powertrain Control Module, mounted under the hood and not too terribly concerned about some moisture or humidity. It controls the powertrain and management of same.

 

I don't know to much about anything but how old is that battery sitting in your H2. I never knew this but a good battery could be bad and cause computer glitches. Seems there are battery checkers that will show the battery is good but will report something inside the battery is bad and that's a problem, electrically.

So ya, I don't know.

 

I had the truck at the dealer for 3 days while they tried to figure out what was wrong, it was then that I was told it was not certain components. Honestly I think they just couldn't figure it out and just wanted to get it back to me and wash their hands of it.

 

I'm open to just about anything at this point. I will purchase a bcm and replace it. I need to also know if anyone has a pdf of a repair manual for the 2003 h2?

 

If you get a used BCM it will need to be from a Hummer with the same options or some things will not work correctly or at all. You will also need to do a security re-learn which is pretty easy. A new BCM can be programmed by a dealer with a Tech2 to the RPO Codes (options) your H2 has.

The other catch with a used BCM is new or different RPO codes cannot be removed or added. That can only be done when they are blank (new) once they are programmed, the VIN is programmed, then the first time security learn is done and that locks them from any reprogramming other than security re-learns. A used one IS fine and will work after a security relearn though but if it came from a vehicle with different options you can have a lot of problems. Things like the rear air ride, base Bose amp or lux Bose amp, etc...

I'd agree though - it does sounds like the BCM got wet from the typical roof leaks and the water happened to run down to the right spot. I've heard of this happening on H2's before. One other that can cause all sorts of issues - the ignition switch. If the contacts behind it are getting screwed up or failing that can also cause all sorts of problems and errors.

Me personally - I'd google around and find a torrent for the GM eSI and get that running. That is the GM Service Info System and for older GM vehicles up to 2005 (a couple of versions floating around that have up to 2009) is the dealer service manual - its electronic. Very nice to have although can be a bit fiddly to get it running. Then I'd tear open the bottom of the dash on the drivers side, pull the BCM out and check its connections for corrosion, etc.

 

I had my EBCM repaired not by BCM. That's why I was asking you what lights specifically were coming on the cluster or if you had any error codes

 

Ah - did not catch that but yes - his issue could indeed be the Ebcm which controls the antilock system, traction control, etc. Those have been known to have bad soldering in them.