C6 Column Lock Bypass (Draft Design)
Thread Starter
Heel & Toe
Joined: Mar 2010
Posts: 21
Likes: 0
C6 Column Lock Bypass (Draft Design)
As many of you know, the 2005 C6 manual trans sold in the US have a column lock motor. This motor is no better and in many ways may be worse than the design used in the C5 family. The Column Lock Bypass built for the C5 cannot be directly used in the C6 due to different connectors and designs in the Column Lock mechanism. Those that have taken one off see a ribbon connector going into the Column Lock mechanism. Many have thought this means the system is now digital in nature. I have disassembled one recently, and the internal components in the Column Lock mechanism are very similar to the C5. I am posting a pdf that documents what I have found so far and what I am planning to do to bypass the column lock mechanism. If you have tried everything else recommended (new battery, battery tender, replaced Column Lock mechanism only to have the new one leave you stranded, the solution I am working on may be an option.
Any good vette techs, please look over what I am planning and let me know if you see any issues. Thanks.....
PDF of design located here:
http://www.corvetteactioncenter.com/...ock-motor.html
Any good vette techs, please look over what I am planning and let me know if you see any issues. Thanks.....
PDF of design located here:
http://www.corvetteactioncenter.com/...ock-motor.html
Thread Starter
Heel & Toe
Joined: Mar 2010
Posts: 21
Likes: 0
I have ordered the raw material. It will take about 10 days until I have time to put it all together and test it. All I am doing in this solution is replacing a single pole double throw (SPDT) microswitch with an equivalent latching relay. I am reusing much of the earlier C5 CLB design efforts (same relay part, same diode layout). I am only making changes necessary to have the relay emulate the way the microswitch works.
When I disassembled the column lock, I found the screw mechanism was made of plastic and was binding. The plastic screw was binding in the plastic block. This is obviously a manufacturing defect and is likely the reason so many of these systems fail. If the screw was a fraction smaller, it would not have this problem.
GM needs to do more in depth QC on these parts. They are getting inferior products from their suppliers.
When I disassembled the column lock, I found the screw mechanism was made of plastic and was binding. The plastic screw was binding in the plastic block. This is obviously a manufacturing defect and is likely the reason so many of these systems fail. If the screw was a fraction smaller, it would not have this problem.
GM needs to do more in depth QC on these parts. They are getting inferior products from their suppliers.
Last edited by mbomba; Aug 16, 2011 at 12:37 AM.
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Racer
Joined: Mar 2011
Posts: 472
Likes: 1
From: Boca Raton Florida
Instead of removing the whole column lock, how about an interface to go between the ribbon cable plug, and module that will prevent the lock from ever engaging. This way its a simpler plug in bypass that will tell the lock never to engage ?
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
Yes an easy solution like the the CLB would be a hot seller!!
Burning Brakes
Joined: Jun 2008
Posts: 1,214
Likes: 3
From: CA
Not sure if this will work for the A4 guys but here's another idea....
The T-56 has two reverse switches on it, which are basically "trip switches". One works with the steering column lock and the other works with the reverse lights. There is a ground (blue) wire that comes from the BCM and splits into two wires right before it gets to the trans. From there each wire goes into each reverse switch. From there a wire comes out of one switch and goes to the SCL module and the other goes back to the BCM.
If you simply disconnect the reverse switch for the SCL then the lock will never engage because it's not being provided with the ground that it needs. By doing this you'll also start getting a "service column lock" msg. I haven't really looked into this but I think the error msg can simply be bypassed. I would need to look at the schematics again.
The T-56 has two reverse switches on it, which are basically "trip switches". One works with the steering column lock and the other works with the reverse lights. There is a ground (blue) wire that comes from the BCM and splits into two wires right before it gets to the trans. From there each wire goes into each reverse switch. From there a wire comes out of one switch and goes to the SCL module and the other goes back to the BCM.
If you simply disconnect the reverse switch for the SCL then the lock will never engage because it's not being provided with the ground that it needs. By doing this you'll also start getting a "service column lock" msg. I haven't really looked into this but I think the error msg can simply be bypassed. I would need to look at the schematics again.
Thread Starter
Heel & Toe
Joined: Mar 2010
Posts: 21
Likes: 0
I left the motor connected to ensure the computer did not see anything different when I change the microswitch with a latching relay. The relay will draw a small amount of current when the motor is energized, but it should mot be enough to change what the computer is expecting to see. I thought about disconnecting the trans reverse connector sense line, but then the dash would nag you with "shift to reverse" messages and the chime would sound when you left the car. Also, Dead Battery Syndrome might be an issue as the computer only fully powers everything down when it senses reverse. I suspect a resistor could be used to simulate the motor load and given the correct connector, a direct CLB package could be built. But getting to the connector to unplug and plug in a bypass is also difficult.
Thread Starter
Heel & Toe
Joined: Mar 2010
Posts: 21
Likes: 0
C6 CLB Final Design
I have updated the design for the 2005 C6 MT6 Column Lock Bypass. I received the required relay yesterday, and after a few hours, had it installed and tested in my 2005 C6. Earlier I had taken the column lock mechanism apart and reassembled the steering column, so all I had to do last night was some soldering and fitting the solution in a project box and finding a place under the dash to attach the project box.
It works... Lock and unlock behaves as expected. I had to use the key fob to reset the alarm when I connected the battery the last time (car thought it had been tampered with). Just press unlock twice fast.
Good luck to anyone that wants to try this. I offer no guarantee or waranty. But if the Column Lock Mechanism is already broke, this is a $30 fix (plus labor) and you never need to worry about being stranded again.
// I cannot find the add attachment link when posting. Just noticed I do not have rights to post attachments.//
The updated design is located at http://www.corvetteactioncenter.com/...0&d=1313784550
It works... Lock and unlock behaves as expected. I had to use the key fob to reset the alarm when I connected the battery the last time (car thought it had been tampered with). Just press unlock twice fast.
Good luck to anyone that wants to try this. I offer no guarantee or waranty. But if the Column Lock Mechanism is already broke, this is a $30 fix (plus labor) and you never need to worry about being stranded again.
// I cannot find the add attachment link when posting. Just noticed I do not have rights to post attachments.//
The updated design is located at http://www.corvetteactioncenter.com/...0&d=1313784550
Last edited by mbomba; Aug 19, 2011 at 04:32 PM.
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
I have updated the design for the 2005 C6 MT6 Column Lock Bypass. I received the required relay yesterday, and after a few hours, had it installed and tested in my 2005 C6. Earlier I had taken the column lock mechanism apart and reassembled the steering column, so all I had to do last night was some soldering and fitting the solution in a project box and finding a place under the dash to attach the project box.
It works... Lock and unlock behaves as expected. I had to use the key fob to reset the alarm when I connected the battery the last time (car thought it had been tampered with). Just press unlock twice fast.
Good luck to anyone that wants to try this. I offer no guarantee or waranty. But if the Column Lock Mechanism is already broke, this is a $30 fix (plus labor) and you never need to worry about being stranded again.
// I cannot find the add attachment link when posting.//
The updated design is located at http://www.corvetteactioncenter.com/...0&d=1313784550
It works... Lock and unlock behaves as expected. I had to use the key fob to reset the alarm when I connected the battery the last time (car thought it had been tampered with). Just press unlock twice fast.
Good luck to anyone that wants to try this. I offer no guarantee or waranty. But if the Column Lock Mechanism is already broke, this is a $30 fix (plus labor) and you never need to worry about being stranded again.
// I cannot find the add attachment link when posting.//
The updated design is located at http://www.corvetteactioncenter.com/...0&d=1313784550
Arrrg. Have to be a member to see it.
If you would email me the pdf to joegut at gmail dot com, I'll attach it here so all can see it.
Thanks for all this work!!
Tech Contributor
Joined: Jul 2002
Posts: 14,949
Likes: 263
From: St. Louis, MO
St. Jude Donor '08
Column Lock Bypass DIY Instructions
Well, the 05 C6 world owes a debt of thanks to MBomba for creating a C6 column lock bypass!
I've attached his DIY instructions below.
Thanks MBomba!
I've attached his DIY instructions below.
Thanks MBomba!
Team Owner
Joined: Sep 2005
Posts: 20,352
Likes: 568
From: Ventura County, Calif
Thank you mbamba for doing this and offering it to others! 
And here's another 
!!
Thank you Joe_G for posting the working link!
Well, my eyes crossed trying to read and understand that so it will be interesting to see how many try this and succeed.
And here's another !!Thank you Joe_G for posting the working link!
Well, my eyes crossed trying to read and understand that so it will be interesting to see how many try this and succeed.