Hi folks,

Just when I was happy with my cammed tune, I had the car stall out on me 3 times in a row in a parking lot due to the column lock issue. This is the first time this has happened to me. Let me explain what happened and how it happened and previous symptoms I've had. First off, when I initially had the car I thought this car had the column lock bypass already done to it because when I move the steering wheel without the key in ignition, it never locks. I can freely rotate the steering wheel all the way left and right without the key (granted it's tough to rotate because the P/S is off). That said, I've had for the last month or two had the yellow 'SECURITY' light flash when I turned the engine off after a drive, but never had any other message or anything. Then last two weeks I underwent my cam build along with LT headers, LS6 intake and the whole nine yards. I don't know if the added vibration of the cam might have had anything to do with provoking this, but yesterday once I started my car after work I had the DIC give me a message of something in the line of "Service Column Lock" and then something in the line of "Remove Key for 10 sec..." something like that. Backing up from the parking lot it stalled. Then about 2-3 more times consecutively right there. It was embarrassing to say the least. I finally pulled up to another parking space and removed the key for some amount of time and restarted engine and I was finally able to go home without further issues. I haven't been able to recreate it since, but I'm afraid to get stranded.

I know there are a lot of posts out there but I'm puzzled because I thought that I had the column lock bypassed since MECHANICALLY the column lock is nonfunctional in my car, so it will never really lock on me. What should I look into? Ignition switch? LMC5 module? I need some guidance here. Thank you.

 

There are two basic types of CLB systems, the early ones used a resister to bypass the system, however over time the resister could fail, for several reasons. The LMC5 uses a system to disable the BCM where the column lock software is operated from. Also, many of the C5 Corvettes have had the GM bypass upgrades applied to its software to get around the problem--they did not work. If you car is an automatic, they basically covered the bolt in the steering column. However all the GM programs also included a 2 mph cutoff into the PCM software so if any of the codes (DTC's) were tripped it would shut off the engine. While this is an over simplification of what could be a problem another factor can run havoc to the program--an aging battery. When the battery in the C5 Corvette goes below 12.5V (ignition off) the low voltage can play havoc to the electronics in the car. Myself, I installed an early CLB system and one morning years late, my original battery finally reached the point of now return and the messages appeared on my screen. Also I had a warranty service performed on the car early on and the dealer also installed 2 mph cutoff-per factory instructions. Fortunately I have the tools necessary to trouble shoot the problem plus a new battery, but I also installed the LMC5 system and haven't had a problem in almost 8 yrs.

 

I just installed an LMC5, it took less than a hour... Compliance Parts

 

Ok, before I buy the LMC5, I want to make sure I don't already have it installed. Where does it go so I can check quickly?

 

Mine is a 1999 M6 car. Not sure how they mechanically removed or blocked the column lock, but I guarantee you it doesn't lock when the car is off and key is off. I'm gonna keep an eye out for my batt voltage from now on. I've never had a battery drainage issue (at least not one that is noticeable in 2 weeks of non-use), but never say never right?

 

If you have an LMC5 it is installed at the body control module in the passenger side kick panel. My guess is you don't have one because you experienced the 2mph fuel cut off that makes the car stall out.
Also note that a steering wheel that does not lock only means that the GM recall was done. It never fixed the problem and just complicated it by adding the 2MPH cut off! Your problem could have been
due to low battery but I would still get and LMC5 and just be done with it ever happening again.

 

There are two systems involved here, first the security system controlled buy the Vehicle Anti Theft (VATs) controlled by a resistor pellet in the key and a comparator circuit in the BCM. If your car starts the VAT's system is working no need to troubleshoot. Next is the column lock controlled by Keyin/Keyout in the ignition switch that again reports the key to the BCM it in turn closes the "Column Lock Relay" (CLR) in the passenger foot well.
The easiest thing to do is confirm the CLR is receiving a ground to close the coil on the relay.
If yes, check the output of the relay it's a SPDT if it's good then the feedback of the lock motor is not getting back to the BCM or
If yes, the coil is closing but the relay has no output the relay is fried
If no, pull the ignition switch and the short the keyin to ground and see if CLR fires if it does then the ignition switch is the problem (I doubt this is the problem)
I would put my money on a fried CLR

 

Look on YouTube. There are videos on the LMC5.

 

Your tuner can raise the 2 mph cutoff. But you should still do the LMC5 if it hasn't been done.

 

UPDATE: I finally got to install the LMC5 this weekend. Unfortunately, I'm still having issues with the 'SECURITY' amber light flashing before and after key on/off on random occasions, and I'm not sure if it's because the LMC5 is defective or not, or if it's something else in the install. I'd like some assistance in troubleshooting the unit or the process. The install procedure is super easy and I don't see what I could've gone wrong! (Instructions and install were great and very straight forward.) Anyways, it seems to be random when it shows the 'SECURITY' flashing light, it doesn't do it all the time I mean. Another observation was that immediately after installing the LMC5, the very first key on test I had the 'Service Column Lock, remove key...." message. It never came back afterwards (not sure if it was a fluke or if maybe the LMC5 needed an initial charge to start working) but it's been a couple days of use already and that 'Service Column Lock' message hasn't came back, but like I said, the 'SECURITY' light occasionally comes up. Please help. My first thoughts on troubleshooting is maybe to put dieletric grease on the male terminals related to the LMC5. Let me know if I should start here or what troubleshooting procedure I should do.

Additional info: I removed the CLR relay by the BCM per the LMC5 instructions during the LMC5 installation, and I also replaced my ignition switch with a brand new OEM AC Delco unit that same day, to avoid future issues.

 

That just means the GM recall has been done; that doesn't mean a column lock bypass has been installed. This is detailed in the sticky (I know the CLB sticky is A LOT of information, but every single word needs to be read inside and out).

All a CLB does is intercept the logics for the column lock signal. It doesn't check to see if a recall was performed (column cannot lock) or not (column can still lock), which is why many CLB vendors including Richard who makes the LMC5 sell 12v unlockers.

Re: your security light, considering you had column lock issues I would first ensure your battery is good. Not checking it by the gauges and DIC but physically confirming it is properly charged and holding a charge. Most CLB and similar issues occur due to a discharging battery, and a further security light issue could be pointing to that. I would confirm batt first before proceeding with further diagnosis.

 

Battery was load tested about two weeks ago and performed stellarly.

 

The security light flashing sometimes means that either your resistor pellet in your key is worn, or the contacts inside the ignition switch that read the resistor pellet are worn, try a second key if you have one or buy a new key.

 

Well, out of those two you can discard the ignition switch. It is brand new OEM AC Delco that I installed the same day as the LMC5. Key is original as far as I know and I don't have a spare.

 

If you have any questions about the LMC5, call Richard at Compliance Parts. He is very helpful.
http://www.complianceparts.com/contactus.html

 

The ignition "switch" does not read the key. The contacts that read the key are in the tumbler that you insert the key in to. You can get spare keys of ebay for under $15 then take it to ANY place that cuts keys with your working key and they can cut it for you. You will need to measure the resistor pellet then look up the key you need. Finally, the security light is part of the VATS system and the LMC5 has nothing to do with that.