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LMC5 Problems

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Old May 3, 2026 | 10:57 AM
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So I installed an LMC5 kit on a 2000 Auto car that was getting the 10 second message. I installed it precisely as instructions stated. I ended up with a car that will now die if I put it in reverse or D. I did it with and without the “brown wire mod”, and I’ve done it with and without the column relay on the passenger floor removed.

I even went as far as putting things back to how they originally were effectively removing the LMC5, and I had the same issue occur.

So I said well, it obviously wasn’t the LMC5 so I put the LMC5 back in and I got one key cycle of being able to put it in gear.. came out this morning same problem

Will start every time, put it in gear it will die.

I have no idea what to do.. is this something that people have frequently had an issue with and if so, what did they do to resolve it?
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Old May 3, 2026 | 09:10 PM
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Many a C5 owner has had the 2 mph fuel shutoff defeated by having a tunner change the 2mph to 200mph.
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Old May 3, 2026 | 11:16 PM
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Originally Posted by mmartinez
Many a C5 owner has had the 2 mph fuel shutoff defeated by having a tunner change the 2mph to 200mph.
But I’m not even moving at all. The second it goes into gear it shuts off. Would that happen with the 2mph thing?
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Old May 3, 2026 | 11:18 PM
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Originally Posted by Hellzgato
But I’m not even moving at all. The second it goes into gear it shuts off. Would that happen with the 2mph thing?
From what I have read Yes it would
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Old May 4, 2026 | 09:21 AM
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Originally Posted by Smoken1
From what I have read Yes it would

I guess logically this makes sense to me, that it is likely the problem.

I’m just having a hard time accounting for the fact that the vehicle was able to start and go into gear before I install installed the LMC5, and now that I tried to do that it doesn’t matter if the LMC5 is wired in or I put the pins back to their stock positions and remove the LMC5. Did I somehow convince the BCM to create this issue every time?

I’ve disconnected the battery for a pretty extended periods of time. Is there a different way to completely reset the BCM or anything?

It’s just pretty annoying that it was working before I tried to do what I thought was a preventative thing
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Old May 4, 2026 | 02:40 PM
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Disconnecting the negative battery cable for a few minutes resets the BCM, you have to make absolutely certain that the wires were plugged in where they were originally, maybe a broken wire where the wire is cripped, I am sure you will figure it out, good luck.
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Old May 4, 2026 | 06:49 PM
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Does anyone think there is any merrit to getting an old school CLB box to install under the column? Since potentially this is all triggered by the system thinking its not getting the unlocked signal from the column lock? Is there potentially another way to bypass this system other than buying HP Tuners and changing the fuel cut?

I'm still unsure that makes since the car doesn't move an inch and dies. If its a 2mph thing wouldn't I have to at least be rolling or are all bets off because this is a tuned cammed car?
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Old May 5, 2026 | 12:42 AM
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Originally Posted by Hellzgato
Does anyone think there is any merrit to getting an old school CLB box to install under the column? Since potentially this is all triggered by the system thinking its not getting the unlocked signal from the column lock? Is there potentially another way to bypass this system other than buying HP Tuners and changing the fuel cut?

I'm still unsure that makes since the car doesn't move an inch and dies. If its a 2mph thing wouldn't I have to at least be rolling or are all bets off because this is a tuned cammed car?
I've had an old-school CLB for 20 years and have never had to think about it. It's mind boggling that so many people have issues with the LMC5 that wouldn't have existed if they had gone with the simple CLB.

CLB FTW!!
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