Hi folks,

I've completely removed the column-lock motor assembly from my C5 racecar, and plan on installing the kit that comes with the recall campaign. Since this is a dedicated track car, I want zero probablility of column lock while "driving" the car.

So - the question is: Will the PCM disable fuel when I try to start it up and/or will there be additional messages on the DIC?

Thanks,
-Bruce

 

All you need to do is mimic the feedback signal to the BCM.

This is exactly what the (aftermarket) CLB or (GM) "harness K" does.

Once you disable the motor electrically, and use either of these feedback devices to satisfy the BCM, the mechanical stuff becomes dead weight.

 

I'm assuming your have an auto trans on your racecar. Because there is no kit with the recall for manual trans C5's. The kit is the GM Harness K column lock bypass for the automatics.

 

The GM kit can also be installed on MN6s.
The dealer can't do it but the car's owner can.

 

Bruce,
I would make a couple of comments. First to satisfy your BCM, you have 3 choices:
1. Install a CLB module which you can purchase from Corvettes of Houston for $49.95 http://www.corvettesofhouston.com/
2. Build your own for less than $25 which you can see my plans at the following link: http://shelor.net/Z/CorvetteForum/Cscokd/
3. Install the (GM) "harness K"
All three of these solutions do the same thing in that they fool the BCM.

From what I know so far, the "GM harness K" actually leaves the column lock motor connected to the BCM yet it adds a CLB relay to fake out the BCM. I assume the only way this would work is for the steering lock plate to be removed. But why would GM leave the lock motor in the circuit? This is a mystery to me. I would be interested to know more about the column lock motor, lock pin and lock plate that you said you removed. Many of us have had a little nagging question in the back of our minds about how the motor and lock pin actually works. It was my belief that the lock motor moves the lock pin via a worm drive gear so it would be basically impossible for the lock pin to jiggle around and accidentally re-engage the lock plate in the steering column even though the CLB has been installed and the lock motor disabled. From your experience after removing yours, can you or any others reading this post shed any light on this subject for us? We would appreciate any info you might be able to provide. Thanks!
John

 

I know that it can be installed but he said "the kit that comes with the recall campaign". The only kit that comes with the recall is for automatics.

 

GM's long-standing "argument" with the aftermarket CLB's, is that by disconnecting the lock motor, the BCM relay contacts that actuate the motor no longer pass any current, and thus don't "cleanse" themselves, and that will eventually cause problems resulting from the dirty/oxidized contacts.

From a pure electrical theory standpoint, electrical contacts do tarnish over time if unused. When passing electrical current, the slight arc that occurs during the closing of the contacts, does tend to renew and clean the connection.

The logical argument to that argument, is that if no problems occur from not transferring any current during this closure of contacts (disconnection of motor)...why would problems occur if those contacts (ithat no longer transfer current) go bad over time, and how would they even be detected if they went undetected before?

Confused? A more simple scenario, but the same situation....

You have a light bulb in your house you never want on anymore.
Your solution is to remove the light bulb, but continue to flip the switch each day...the room never lights up due to the missing bulb.

GM is saying doing that could cause the light switch to go bad.....but how do you know the switch is bad if it doesn't do anything to begin with?

 

Thanks and I appreciate your comments and electrically understand where you're coming from. One follow up comment would be that the relay contacts that operate the lock motor are also what switches the CLB latching relay, so if they fail then the BCM will get the wrong feedback signal.

 

That's certainly possible, and could well be the logical explanation. Very good point.

 

Yes, what they are claiming is that the current to drive the motor of the stock CL is significantly less than what it takes to energize the coil to flip the relay contacts.. I for one am not worried about it..

BTW, if you use a single-coil relay like I did, you can skip the diodes.

 

To the track car guy I say dump the motor you don't want the weight. But I think the motor itself feedsback to the BCM that it is there. So you need it. Also, the Harness K is just GM's CLB and like all good competators they bad mouth the other guy. GM would never support a CLB aftermarket to tamper with their design . Olny GM can screw up there own designs. The Harness K is a CLB. The lock plate blockoff physically prevents the motor from every locking and is used on automatics only. GM can't do this on M6's because then the car can be unintendedly rolled away by a kid. So only you can put the block out plate in. The CLB electronically disables the lock from moving but does not prevent it from doing so. Only the lockplate provides a physical barrier. This I gather from reading hours of threads on the CLB. What I would like to know is that this recall came out for cars about 97-2000? But GM still made C5's. So when did they finally put the harness K in the C5's upon delievery? 2003? 2004? Has anyone had a 2004 C5 lock up?

 

What's your point?
He said he was going to install it.
The "only" kit that comes with the recall for A4s and the "only" kit you can purchase to install in a MN6 are one in the same.

 

Yes they are one in the same but he stated the kit came with the recall when in fact it did not for manual trans C5's.

 

Yup, the car will stall at 2mph. Your DIC will display the " Pull key, Wait ten seconds ". All the CLB's have to be installed with a functioning lock as a springboard. Regardless if you install the A4 plate. If I remember correctly you start off by unplugging the lock, then plug in the CLB, then gingerly insert two wire extension from colum lock into cigarette lighter to unlock the lock. The harness then mimics the lock motor.

 

The reason the kit says its for automatics is that the government says a car must have at least a coluum lock or shifter lock. By installing this kit on an MN6 the dealer is breaking the law by disableing the coluum lock since the MN6 shifter can not be locked

 

Thanks for the helpful info - since I've already brutalized the column and removed the motor, here is what I've found:

The motor drives a pin and the pin physically opens/closes a small micro-switch. When the pin is retracted (un-locked), the switch is closed (completes a circuit). When the pin is extended, the switch is open. The motor and pin are an integral assembly.

I don't have the service manual in front of me, but I recall something (PCM or BCM) sensing the voltage on that circuit (typical sensing circuit with 12v followed by a resistor - if the circuit is closed, the module "sees" 12v; if the circuit is open, it "sees" a reduced voltage determined by the internal resistor in the module).

With this setup, there is a delay between the unlock/lock command, and the output of the feedback circuit that determines the state of the lock mechanism. Is the module smart enough to look for this delay? Is the module "looking" for the state transition? In other words, when I lock the column, does the BCM/PCM look for the voltage on the sensing circuit to go from "high" to "low"? Or, does the PCM/BCM simply care that the sensing circuit shows "low" when the column is locked (e.g. it doesn't look for the voltage transition)?

Thanks,
-Bruce

 

The column lock itself is nothing more than motor that moves a pin out(up) and back in(down). When the pin is out it is sticking into a washer that has holes drilled into it. That is what locks the column. When GM does the recall on autos, the washer with holes is taken out and a new washer (spacer) is installed. The pin then has no holes to lock into and therefore the column can not be locked. The motor does still move the pin in and out each time. With a CLB the motor does not receive a signal to move the pin out. So it can never lock.

 

Again, I understand all this. I was just correcting what another member stated as being false.

 

Sorry - I didn't mean to confuse anyone. The recall campaign is for automatics. I plan on installing the harness from *that* kit on my manual-equipped racecar.

-Bruce

 

If you get the PCM reflashed at the dealer, it will change the firmware in Segment 1 for the fuel shut off. If you plan on tracking the car, I would avoid the PCM reflash.