ncali

What does this consist of? How does it work? How does it tell this car that there is no need to lock up the column
and tell it not to cut the fuel off. I just put mine in and while I was laying there all twisted up I thought that for the price you would think that GM would have made this a repair for their recall

laurent_zo6

This should explains all:

http://www.complianceparts.com/c5collockdesc.html
http://www.complianceparts.com/lmc5ataglance.html

Gordy M

Regarding the 2 mph fuel cut off, If you car was ever in for a GM service since 2002, it was programmed into the PCM. The LMC5 does not control that problem (it is connected to the BCM). The problem with the 2 mph shutoff is usually a battery problem. If the battery goes to 12.5V or less--measured with a VOM and the engine off--weird events happen to the Corvette and triggering the fuel cutoff is one of them. the GM dealer cannot help with changing that but someone with tuning equipment can. Finally, you should always keep a battery tender on the car if you are not driving it at least once a week

Velocity_Vette

It didn't exist back in the day. The LMC5 that Richard makes is only a more "recent" bypass, in the history of C5 column lock issues.

Most everyone knows that the GM "fixes" didn't really "fix" anything, but circa that time period in the later 90s/early 2000s when GM was dealing with column lock and subsequently servicing cars the only item owners could rely on outside GM work was the old-school (heh) under-column bypasses. Those bypasses that can still be found periodically (I actually have one on my car and do not have an LMC5) do not do the same work as the LMC5. The under-column bypasses interface with the column directly via a relay, whereas the LMC5 bypasses all column lock signals at it's source; the EBCM. The other issue was for most individuals the under-column bypass was fairly difficult to install, in that you had to remove all the lower column kick panel assembly and install the bypass, whereas for the LMC5 you just remove the footwell service panel and install.

feeder82

GM is required by federal law to have a column lock device, the LMC5 device defeats the column lock. The GM recalls all attempted to keep it in place and ultimately failed

TomWoodgeard

What is the "brown wire mod" that I see in several threads. (Search option SUCKS)

laurent_zo6

Some Corvette owners are still seeing the "wait 10 sec" error message. Compliance Parts recommends these owners to do the "brown wire mode" which is described on page 2 of the instructions. Look at the bottom of this attachment below

TomWoodgeard

Thank you! Now I know.

laurent_zo6

You're welcome.

v6turbo87

The 2mph cut of was part of GM's column lock recall. It was put in to prevent the car from being driven in the event that the steering column did lock up while they car was being driven. Yes a low battery can trigger it but it is because the low voltage causes issues with the column lock system. The LMC5 does in fact prevent this from happening.

leadfoot4

I've never had any problems with my steering column locking up, most likely because I modified the "locking ring" in the steering column, by machining off the portion of the ring that has the "locking detents". Therefore, while my car's locking motor still cycles the lock pin in and out, it doesn't hit anything, therefore there's no potential "strain" on the lock mechanism. So it still functions as designed, but it doesn't engage the lock plate, therefore it doesn't actually lock the column. I did this many years ago.

HOWEVER, given the potential for an issue to develop, I bought an LMC5 device last fall, with the intention of installing it right away. But as many of us have experienced, life gets in the way, then winter hit, so the car got parked. And since you want to be able to test the car immediately after installing the LMC5 module, I put it off.....

Spring is now here, and I want to finally install this kit. Maybe it's me, but after reading the instructions a couple of times, they seem to contradict themselves, somewhat, in places. It starts out by saying that if your steering wheel still locks up when the key is removed, you have to follow a "special" instruction. HUH? The column locking when the key is removed, is SUPPOSED to be the correct operation, right? So if I understand this instruction, I have to perform a special operation, if my column lock is operating as designed?

Secondly, many here have recommended performing the "brown wire mod", no matter what. OK, I understand, but the instructions say to perform the "bwm" after I install the LMC, and find the dreaded "wait 10 seconds" message on the DIC. Assuming I want to perform the "bwm", should I do it first, BEFORE I begin to install the LMC, to save time and later effort?

Thanks for any advice!

JWM

Disregard the special instructions and perform the brown wire mod during installation or, don't bother to install it given the fact that you obviously defeated the system many years ago. Just my .02

leadfoot4

That's what I was thinking would be the way to go. My only reasoning for the LMC5 is to prevent something totally unexpected from happening, like the column lock motor hanging up or even dying,and leaving me stranded, sometime in the future.

jjc508520

Brown-wire modder present!

leadfoot4

I installed the LMC5, about a half hour ago, following closely, I think, the instructions, yet as is "par" for me, something isn't going correctly.


EDIT.... OK, I went back and found that I had made a mistake. When doing the "brown wire mod", I cut the short brown wire loop, and capped the ends, with the supplied plastic caps, per the instructions. The problem was, I stopped reading right there, and overlooked the second part of this step, where you remove one of the other wires, and substitute the OTHER brown wire that comes out of the LMC module. Once that was corrected, I seem to be in good shape......

JWM

I would begin by making sure that all four connections were performed IAW the instructions.