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Pcm Ecm Vcm

Discussion in 'Chevy Trucks' started by Rick Loncosky, Jun 20, 2004.

  1. Rick Loncosky

    Rick Loncosky Senior Member
    from 17557
    Messages: 102

    My nephew has a 1999 Chevy 1/2 ton 4x4. His "check engine light" has been on continuous. He had it to his local mechanic and the guy said he has a sort in the "ECM". I went to the closest GMC truck dealer and he says it a "PCM," same thing. The local mechanic meant Emission control module. the dealer thought I meant "Engine Control Module" so they replaced it for just under $500. Half a block away from the garage the light comes back on. The bill says they replaced the "VCM or Vehicle Control Module." The dealer says there is only 1 computer on this truck. Is this correct? It's titled 99 but some components have to be bought for 98. It has a throttle body and not direct port injection. This I seen today, but it's still says Vortec on the little cover on throttle body. What's the difference in Vortec or not? Any ideas how many on board computers trucks have, 1,2, or 3? It seams to runs OK. Any other help would be of help, thanks.
  2. ratlover

    ratlover PlowSite.com Addict
    from IL
    Messages: 1,325

    they went to vortec with the new heads in 95 I think. No idea on the rest of the stuff sorry. If you were told a specific part was bad and it didnt fix the problem then IMO it isnt on your bill. no idea how many computers.