Service column lock revisited
04-19-2007, 12:29 AM
#1
Advanced
Thread Starter
Service column lock revisited
The problem restated and a possible fix?
Whether an A4 or MN6 after going through all the factory recalls and / or installing a CLB does not guarantee you will not have a problem again. It is only a matter of time until you do. It is a time bomb we live with.
Removing the lock plate, Rev K harness, Reflash , new actuator,new battery,Rev. K, CLB , rain dance, you can still still have a failure.
Leaving the actuator in place is a problem, it should be eliminated.When the pull in coil opens up,(burns out) in the actuator it is service column lock time and the fuel will be cut off > 2 mph.
Even though the lock plate is removed, the current rev. software will shut off the fuel if the BCM becomes unhappy for a myriad of reasons. The fuel shut off FEATURE should be coded out, because if there is any bcm perceived problem, without the lock plate it can't lock the steering column anyways.The general has failed us here.
The Rev K harness is a compromised.Even the newer Rev K harness with the later style less likely to fail relays. It should be redesigned.
The CLB is a reasonable fix however not without potential issues. An out of sync actuator or possible BCM failure due to the floating connection that used to go to the actuator
**************************************** **************
So...would is be possibe to do this ?
Assuming that you have had the recalls done, Rev K harness, lock plate removed etc.
One relay in the rev k harness provides feedback to the BCM
The actuator is left in place to provide the proper impedence to the BCM circuit to load it properly.I am assuming that without the actuator in place as in the case of he clb, that node left open in the circuit, the voltage gets too high at that point and perhaps cause component damage?:
So if you measure the actuator pull in coil impedence and shove a resistor of the same resistance in the harness with a Pdiss rating equivalent of the actuator won't that work?
This way the actuator is out if the circuit forever and can be removed from the column !
And with respect to the failure prone relays,one in the passenger footwell and the other under the steering column, why not use some hi rel mil spec type relays to replace them with? No more relay issues!
So the fix should have been..Rev K with hi rel relays,Remove lock plate, eliminate / remove actuator & put an equivalent resistor in the harness where is used to hook to the actuator & remove the actuator, New software to disable fuel shutoff.
So if you already have the rev K installed, except for the reprogramming to defeat the fuel cutoff,(which a tuner can do) we could do all the above.
Am I missing something here?
Whether an A4 or MN6 after going through all the factory recalls and / or installing a CLB does not guarantee you will not have a problem again. It is only a matter of time until you do. It is a time bomb we live with.
Removing the lock plate, Rev K harness, Reflash , new actuator,new battery,Rev. K, CLB , rain dance, you can still still have a failure.
Leaving the actuator in place is a problem, it should be eliminated.When the pull in coil opens up,(burns out) in the actuator it is service column lock time and the fuel will be cut off > 2 mph.
Even though the lock plate is removed, the current rev. software will shut off the fuel if the BCM becomes unhappy for a myriad of reasons. The fuel shut off FEATURE should be coded out, because if there is any bcm perceived problem, without the lock plate it can't lock the steering column anyways.The general has failed us here.
The Rev K harness is a compromised.Even the newer Rev K harness with the later style less likely to fail relays. It should be redesigned.
The CLB is a reasonable fix however not without potential issues. An out of sync actuator or possible BCM failure due to the floating connection that used to go to the actuator
**************************************** **************
So...would is be possibe to do this ?
Assuming that you have had the recalls done, Rev K harness, lock plate removed etc.
One relay in the rev k harness provides feedback to the BCM
The actuator is left in place to provide the proper impedence to the BCM circuit to load it properly.I am assuming that without the actuator in place as in the case of he clb, that node left open in the circuit, the voltage gets too high at that point and perhaps cause component damage?:
So if you measure the actuator pull in coil impedence and shove a resistor of the same resistance in the harness with a Pdiss rating equivalent of the actuator won't that work?
This way the actuator is out if the circuit forever and can be removed from the column !
And with respect to the failure prone relays,one in the passenger footwell and the other under the steering column, why not use some hi rel mil spec type relays to replace them with? No more relay issues!
So the fix should have been..Rev K with hi rel relays,Remove lock plate, eliminate / remove actuator & put an equivalent resistor in the harness where is used to hook to the actuator & remove the actuator, New software to disable fuel shutoff.
So if you already have the rev K installed, except for the reprogramming to defeat the fuel cutoff,(which a tuner can do) we could do all the above.
Am I missing something here?
Last edited by RGAZ; 04-19-2007 at 09:21 AM.
04-20-2007, 09:21 AM
#2
The one thing that everyone should be aware of, is that the CLB is
best used when there is NO problem. If your column lock is working
fine, NOW is the best time to install a CLB.
Then, if the CLB fails, it only takes 15 minutes in the field to
reconnect the stock column lock motor and almost certainly
be on your way again. Then, you can replace the faulty CLB
while driving with the column lock motor active.
The CLB really is the easiest solution, with the best fallback.
04-20-2007, 08:38 PM
#3
Drifting
The problem restated and a possible fix?
Whether an A4 or MN6 after going through all the factory recalls and / or installing a CLB does not guarantee you will not have a problem again. It is only a matter of time until you do. It is a time bomb we live with. there are no guarantees in life except taxes and death, certainly nowhere to be found in your Corvette
Removing the lock plate, Rev K harness, Reflash , new actuator,new battery,Rev. K, CLB , rain dance, you can still still have a failure. I take that back, that's a guarantee - you will eventually have a failure
Leaving the actuator in place is a problem, it should be eliminated.When the pull in coil opens up,(burns out) in the actuator it is service column lock time and the fuel will be cut off > 2 mph.
the column lock is a integral part of your steering column and cannot be removed, however it can be casterated though
Even though the lock plate is removed, the current rev. software will shut off the fuel if the BCM becomes unhappy for a myriad of reasons. The fuel shut off FEATURE should be coded out, because if there is any bcm perceived problem, without the lock plate it can't lock the steering column anyways.The general has failed us here.
The Rev K harness is a compromised.Even the newer Rev K harness with the later style less likely to fail relays. It should be redesigned.
The CLB is a reasonable fix however not without potential issues. An out of sync actuator or possible BCM failure due to the floating connection that used to go to the actuator
**************************************** **************
So...would is be possibe to do this ?
Assuming that you have had the recalls done, Rev K harness, lock plate removed etc.
One relay in the rev k harness provides feedback to the BCM
The actuator is left in place to provide the proper impedence to the BCM circuit to load it properly. I am assuming that without the actuator in place as in the case of he clb, that node left open in the circuit, the voltage gets too high at that point and perhaps cause component damage?: No...it's not the voltage, its relay switching glitches on the Lock and Unlock command lines. The motor acts like a inductive filter to mask these glitches so the K harness relay will ignore them...it's really a poor design
So if you measure the actuator pull in coil impedence and shove a resistor of the same resistance in the harness with a Pdiss rating equivalent of the actuator won't that work? no...resistance is not inductive/capacitive and so there is no filtering function
This way the actuator is out if the circuit forever and can be removed from the column !
And with respect to the failure prone relays,one in the passenger footwell and the other under the steering column, why not use some hi rel mil spec type relays to replace them with? No more relay issues! this has merit. we could find a better quality relay
So the fix should have been..Rev K with hi rel relays,Remove lock plate, eliminate / remove actuator & put an equivalent resistor in the harness where is used to hook to the actuator & remove the actuator, New software to disable fuel shutoff.
So if you already have the rev K installed, except for the reprogramming to defeat the fuel cutoff,(which a tuner can do)I'm not sure about this. Can just any tuner re-program the PCM to eliminate the fuel cutoff? we could do all the above.
Am I missing something here? yes...don't make it so complicated; put in a CLB and enjoy your car until your guarantee expires
Whether an A4 or MN6 after going through all the factory recalls and / or installing a CLB does not guarantee you will not have a problem again. It is only a matter of time until you do. It is a time bomb we live with. there are no guarantees in life except taxes and death, certainly nowhere to be found in your Corvette
Removing the lock plate, Rev K harness, Reflash , new actuator,new battery,Rev. K, CLB , rain dance, you can still still have a failure. I take that back, that's a guarantee - you will eventually have a failure
Leaving the actuator in place is a problem, it should be eliminated.When the pull in coil opens up,(burns out) in the actuator it is service column lock time and the fuel will be cut off > 2 mph.
the column lock is a integral part of your steering column and cannot be removed, however it can be casterated though
Even though the lock plate is removed, the current rev. software will shut off the fuel if the BCM becomes unhappy for a myriad of reasons. The fuel shut off FEATURE should be coded out, because if there is any bcm perceived problem, without the lock plate it can't lock the steering column anyways.The general has failed us here.
The Rev K harness is a compromised.Even the newer Rev K harness with the later style less likely to fail relays. It should be redesigned.
The CLB is a reasonable fix however not without potential issues. An out of sync actuator or possible BCM failure due to the floating connection that used to go to the actuator
**************************************** **************
So...would is be possibe to do this ?
Assuming that you have had the recalls done, Rev K harness, lock plate removed etc.
One relay in the rev k harness provides feedback to the BCM
The actuator is left in place to provide the proper impedence to the BCM circuit to load it properly. I am assuming that without the actuator in place as in the case of he clb, that node left open in the circuit, the voltage gets too high at that point and perhaps cause component damage?: No...it's not the voltage, its relay switching glitches on the Lock and Unlock command lines. The motor acts like a inductive filter to mask these glitches so the K harness relay will ignore them...it's really a poor design
So if you measure the actuator pull in coil impedence and shove a resistor of the same resistance in the harness with a Pdiss rating equivalent of the actuator won't that work?
no...resistance is not inductive/capacitive and so there is no filtering functionThis way the actuator is out if the circuit forever and can be removed from the column !
And with respect to the failure prone relays,one in the passenger footwell and the other under the steering column, why not use some hi rel mil spec type relays to replace them with? No more relay issues!
this has merit. we could find a better quality relaySo the fix should have been..Rev K with hi rel relays,Remove lock plate, eliminate / remove actuator & put an equivalent resistor in the harness where is used to hook to the actuator & remove the actuator, New software to disable fuel shutoff.
So if you already have the rev K installed, except for the reprogramming to defeat the fuel cutoff,(which a tuner can do)I'm not sure about this. Can just any tuner re-program the PCM to eliminate the fuel cutoff? we could do all the above.
Am I missing something here? yes...don't make it so complicated; put in a CLB and enjoy your car until your guarantee expires
John
04-21-2007, 12:19 AM
#4
Advanced
Thread Starter
Great feedback !
Thanks for the awesome feedback.
Agree the easiest preemptive move is the CLB.
However I like to debate the GM fix with a bud who is a vette tech.
John,
Your comments make total sense to me.
Do you have a waveform of the inductive kicback from the lock/unlock command?
Do you know the equivalent model of the coil.
Sounds like you may have simulated this?
Appreciate the feedback.
Rgds,
RGAZ
Agree the easiest preemptive move is the CLB.
However I like to debate the GM fix with a bud who is a vette tech.
John,
Your comments make total sense to me.
Do you have a waveform of the inductive kicback from the lock/unlock command?
Do you know the equivalent model of the coil.
Sounds like you may have simulated this?
Appreciate the feedback.
Rgds,
RGAZ
04-21-2007, 02:07 AM
#5
Drifting
the relay that was added in the passenger footwell actually puts glitches on the Lock command line (when you first turn your ignition key on) which can cause the K Harness and also the CLB to switch by mistake and get out of sync with the BCM. Many that have this second relay under the passenger footwell cannot get their CLB to work properly because of this. That's why I recommend removing it and bypassing it to restore the command line back to stock. When GM came up with the K Harness, it's my belief that the inductance and capacitance of the column lock motor filters the line somewhat from the switching spikes and most K Harness relays will work but seem to fail shortly after installation. Also I don't think GM put any diodes across their relay coils. If you disconnect the column lock motor from the K Harness the problem appears to be aggrevated. The relay in the footwell was put in to prevent a lock command to ever occur while driving the car. In my opinion it was only to protect GM from a lawsuit.
I haven't modeled the circuit, but I built my own CLB for my 98 and it's never seen a dealer or recall, so my PCM was never re-programmed. When I was building my own CLB, I drove my car everyday for a month with the service column lock error message and my fuel never shut off once. All I did was reset the error message on the DIC each time I drove it. My CLB has been working flawlessly for several years now. I recently installed a Vette Essentials steering wheel and while I was into it, I decided to rework the steering lock plate which you can see the photos on the following thread:
http://forums.corvetteforum.com/show....php?t=1673633
I have a power point file with lots of pics and info related to the column lock issue. If you are interested email me at cscokd@gmail.com. It's a 4M file so be patient when you download it.
Cheers,
John
I haven't modeled the circuit, but I built my own CLB for my 98 and it's never seen a dealer or recall, so my PCM was never re-programmed. When I was building my own CLB, I drove my car everyday for a month with the service column lock error message and my fuel never shut off once. All I did was reset the error message on the DIC each time I drove it. My CLB has been working flawlessly for several years now. I recently installed a Vette Essentials steering wheel and while I was into it, I decided to rework the steering lock plate which you can see the photos on the following thread:
http://forums.corvetteforum.com/show....php?t=1673633
I have a power point file with lots of pics and info related to the column lock issue. If you are interested email me at cscokd@gmail.com. It's a 4M file so be patient when you download it.
Cheers,
John
Last edited by Cscokd; 04-21-2007 at 12:45 PM.
04-21-2007, 11:43 AM
#7
Le Mans Master
John,
Thanks for your detailed explanation. Everytime I read one of your posts, I still learn more about how this system is supposed to work.
Does your comment about the relay in the BCM mean that it is possible for it to create a glitch that could lock the column while driving? I have seen posts where members have disconnected the actuator side of the Harness K and it has worked for several years without problems.
I started out in Electrical Engineering, and switched to Mechanical Engineering, and electrical problems like this just make me glad I did.
Thanks for your detailed explanation. Everytime I read one of your posts, I still learn more about how this system is supposed to work.
Does your comment about the relay in the BCM mean that it is possible for it to create a glitch that could lock the column while driving? I have seen posts where members have disconnected the actuator side of the Harness K and it has worked for several years without problems.
I started out in Electrical Engineering, and switched to Mechanical Engineering, and electrical problems like this just make me glad I did.
Last edited by TEXHAWK0; 04-21-2007 at 11:52 AM.
04-21-2007, 12:41 PM
#8
Drifting
John,
Thanks for your detailed explanation. Everytime I read one of your posts, I still learn more about how this system is supposed to work.
Does your comment about the relay in the BCM mean that it is possible for it to create a glitch that could lock the column while driving? No...it is supposed to prevent the Lock command from getting through once your column is unlocked. But while the unlock cycle is happening, the Lock Command line can have a glitch on it that will immediately switch the CLB or K Harness relay into the Lock state and confuse the BCM. The column lock motor was immune to any switching glitches because it operates so slowly like seconds compared to a relay which switches in milliseconds and therefore will see these glitches . I edited my original post because I don't want anybody to misunderstand here. I have seen posts where members have disconnected the actuator side of the Harness K and it has worked for several years without problems. Agree
I started out in Electrical Engineering, and switched to Mechanical Engineering, and electrical problems like this just make me glad I did.
Thanks for your detailed explanation. Everytime I read one of your posts, I still learn more about how this system is supposed to work.
Does your comment about the relay in the BCM mean that it is possible for it to create a glitch that could lock the column while driving? No...it is supposed to prevent the Lock command from getting through once your column is unlocked. But while the unlock cycle is happening, the Lock Command line can have a glitch on it that will immediately switch the CLB or K Harness relay into the Lock state and confuse the BCM. The column lock motor was immune to any switching glitches because it operates so slowly like seconds compared to a relay which switches in milliseconds and therefore will see these glitches . I edited my original post because I don't want anybody to misunderstand here. I have seen posts where members have disconnected the actuator side of the Harness K and it has worked for several years without problems. Agree
I started out in Electrical Engineering, and switched to Mechanical Engineering, and electrical problems like this just make me glad I did.
Cheers,
John
Last edited by Cscokd; 04-21-2007 at 12:57 PM.
04-22-2007, 12:11 PM
#9
Drifting
Some real world feedback. I installed the CLB immediately when I bought my car 7 years ago. I have never had any problems before or since.
I'm also an electrical engineer and traced the schematics in detail many times in the past. The bottom line is the BCM will send LOCK or UNLOCK voltage and monitor the feedback switch for LOCK or UNLOCK status. The CLB does not generate voltage, but rather passes the BCM voltage back just like the acutator's feedback switch. IMHO, it's been the best solution to this problem and continues to be.
I agree with the comment that if the CLB ever does fail all I need to do is reconnect the CL motor and I'm on my way.
I'm also an electrical engineer and traced the schematics in detail many times in the past. The bottom line is the BCM will send LOCK or UNLOCK voltage and monitor the feedback switch for LOCK or UNLOCK status. The CLB does not generate voltage, but rather passes the BCM voltage back just like the acutator's feedback switch. IMHO, it's been the best solution to this problem and continues to be.
I agree with the comment that if the CLB ever does fail all I need to do is reconnect the CL motor and I'm on my way.
04-22-2007, 02:59 PM
#10
Drifting
Some real world feedback. I installed the CLB immediately when I bought my car 7 years ago. I have never had any problems before or since.
I'm also an electrical engineer and traced the schematics in detail many times in the past. The bottom line is the BCM will send LOCK or UNLOCK voltage and monitor the feedback switch for LOCK or UNLOCK status. The CLB does not generate voltage, but rather passes the BCM voltage back just like the acutator's feedback switch. IMHO, it's been the best solution to this problem and continues to be.
I agree with the comment that if the CLB ever does fail all I need to do is reconnect the CL motor and I'm on my way.
I'm also an electrical engineer and traced the schematics in detail many times in the past. The bottom line is the BCM will send LOCK or UNLOCK voltage and monitor the feedback switch for LOCK or UNLOCK status. The CLB does not generate voltage, but rather passes the BCM voltage back just like the acutator's feedback switch. IMHO, it's been the best solution to this problem and continues to be.
I agree with the comment that if the CLB ever does fail all I need to do is reconnect the CL motor and I'm on my way.
Email me and I'll send you my slideset. You'll find the material very interesting from an engineering perspective. The reason you are very satisfied with your CLB solution is likely because none of these recalls made their way into your car. Some folks have had these recall mods or even production models came with them incorporated which have done nothing for the reliabitilty of their cars but cause further confusion on this forum and frustration for the owners. This whole issue is an amazing series of poor decisions that GM has made while the right solution could have been so simple.
Cheers,
John
cscokd@gmail.com
Last edited by Cscokd; 04-22-2007 at 03:03 PM.
