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View Full Version : Anyone had their VCM replaced ?

Magnacharged H2
11-27-2008, 02:59 AM
My H2 is at the dealer now for the dreaded air suspension not filling the air bags and it has been tracked down to the VCM.
HUMTECH
11-27-2008, 04:33 AM
VCM? Or the ECAS module? (Air suspension module). Pretty much only a few components involed in the air suspension, module, ride height sensors, compressor assembly and the relay. VCM sounds like vehicle communication module to me and has nothing to do with the air suspension. Does your onstar work?
Magnacharged H2
11-27-2008, 05:08 AM
Its an o3 and the tech is getting a left rear door ajar after trying to track down a wire he found the VCM in the dash was not sending a signal back to the compressor to turn it on. Something about 5v signal . Never used my on star. This all started today when trouble shooting my air suspension. Its at sewel plano hummer in tx.
HUMTECH
11-27-2008, 07:55 AM
If the left rear door ajar signal is present the air suspension will be disabled. The system is disabled anytime a door is open. I would be looking at the left rear door latch assembly not sending the closed signal to the ecm.
Magnacharged H2
11-27-2008, 04:11 PM
They started at the latch on the rear left door . Even switched out a latch on the door and same thing. That is when they found the VCM problem. My truck has had alot of after market wiring done for racklights,stereo,etc. This was done before I bought the truck. Tech said he found a rats nest of wires up under the dash. My after market rack lights have never worked since I bought the truck early this year. I have power to all three over head switches but not lights.
HUMTECH
11-27-2008, 11:52 PM
I feel for him, aftermarket wiring especially when poorly done can be a nightmare. Good luck
Planohummer
12-08-2008, 06:18 PM
The cat in pic should take care of rats nest:D
Any chance they're talking about BCM(Body Control Module)? it's what gets the door open signals as well as many other things.
IRA51
12-09-2008, 01:30 AM
+1 on the BCM that's behind the light switch in the dash .
Magnacharged H2
12-13-2008, 03:47 AM
you guys are right , turned out to be the BCM . They,ve only seen a few BCM ever needing replacement. :crying:
IRA51
12-13-2008, 06:27 PM
bcm'S GOING BAD OR NEEDING A REPROGRAM IS NOT UNUSUAL. tech 2 tool needed.