Lmc5
02-17-2019, 01:23 AM
#1
Lmc5
Trying to decide on installing this on my car. I believe the column lock repair was done at a local dealer by the previous owner. I dont know if the
2 mph cutoff was tuned into it but I have seen the pull key out message a few times and not had a problem with the fuel cutoff. So would an LMC5
be necessary as well?
2 mph cutoff was tuned into it but I have seen the pull key out message a few times and not had a problem with the fuel cutoff. So would an LMC5
be necessary as well?
02-17-2019, 03:56 AM
#2
Advanced
I just installed this into my C5Z and I haven't taken it out for a test drive yet but my steering wheel no longer locks so I'm happy. I did have to install the optional brown wire for the "small percentage of C5 BCM's" who still throw the "Pull key, wait 10 seconds" fuel cut off message. After installing the brown wire, that message disappeared also.
02-17-2019, 09:20 AM
#3
Le Mans Master
The 2 mph cutoff was part of a factory reprogramming of the PCM that was done to ensure that the car could not be driven if the PCM did not receive a signal from the BCM telling it that the column was unlocked. It didn't matter if the column was unlocked or not, if the PCM didn't receive the signal, it would allow you to start the car but shut the engine off if you went faster than 2 mph.
This was Chevrolet's solution to ward off lawsuits resulting from a customer starting the car, and then driving off only to discover the column was still locked and having an accident. It really did nothing to address the underlying problem which was a failure prone design. The way it works is the solenoid that unlocks the column must trigger a micro switch (within the column lock motor) that sends a signal to the BCM telling it the column is unlocked. If the solenoid unlocks the column, but either doesn't trigger the micro switch or the switch is defective, the engine can start but at ~ 2mph will shut the engine off. It was cheaper to do this than fix the problem of a poor engineering design.
Some dealers early on would replace the entire column lock motor, but my belief is someone at GM decided it was too expensive to do this, especially once the warranty ran out. I don't recall hearing of any Dealers that would install a column lock bypass on the C5. They were probably prohibited by GM from doing this and to my knowledge GM never authorized it as a solution to the problem.
Good luck... GUSTO
This was Chevrolet's solution to ward off lawsuits resulting from a customer starting the car, and then driving off only to discover the column was still locked and having an accident. It really did nothing to address the underlying problem which was a failure prone design. The way it works is the solenoid that unlocks the column must trigger a micro switch (within the column lock motor) that sends a signal to the BCM telling it the column is unlocked. If the solenoid unlocks the column, but either doesn't trigger the micro switch or the switch is defective, the engine can start but at ~ 2mph will shut the engine off. It was cheaper to do this than fix the problem of a poor engineering design.
Some dealers early on would replace the entire column lock motor, but my belief is someone at GM decided it was too expensive to do this, especially once the warranty ran out. I don't recall hearing of any Dealers that would install a column lock bypass on the C5. They were probably prohibited by GM from doing this and to my knowledge GM never authorized it as a solution to the problem.
Good luck... GUSTO
02-17-2019, 12:56 PM
#4
Le Mans Master
If you haven't bought and installed the LMC5 module ... do yourself a favor and DO IT! The other factory method is a patch not a fix...
02-17-2019, 07:36 PM
#8
Le Mans Master
Just do it. All good, no negatives.
