Column Lock and Stability Management
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
I'll do some research and see if I can figure out how to correctly test the steering position sensor.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
Here is info on the SWPS. Let me know if you need more.
http://forums.corvetteforum.com/c5-t...ring-rack.html
I can also look at the FSM and see exactly what tests can be done for the Yaw sensor.
http://forums.corvetteforum.com/c5-t...ring-rack.html
I can also look at the FSM and see exactly what tests can be done for the Yaw sensor.
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
Great News!
Installed the LMC5 over the weekend and the Column Lock problem is GONE. For the first time in a couple years, I have full control of my DIC display without it being taken over by the column lock message. Thanks guys!!
However, the Stability Control system is as bad as ever. Faulted on me this weekend again when I got a little carried away. Won't be able to work on this again for a couple weeks, but I hope to do some more testing and have something figured out before June 21 for the 1/2 Mile Event.
Special thanks to dadaroo. I'll take a look at that link and look a bit more closely at the yaw and steering position sensors when I can.
Installed the LMC5 over the weekend and the Column Lock problem is GONE. For the first time in a couple years, I have full control of my DIC display without it being taken over by the column lock message. Thanks guys!!
However, the Stability Control system is as bad as ever. Faulted on me this weekend again when I got a little carried away. Won't be able to work on this again for a couple weeks, but I hope to do some more testing and have something figured out before June 21 for the 1/2 Mile Event.
Special thanks to dadaroo. I'll take a look at that link and look a bit more closely at the yaw and steering position sensors when I can.
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
Stability control system faulted today randomly and locked up the front right brake making the car dive to the right at 70mph for a split second before it released. Good times.
Pulled over at the nearest lot and took apart the dash and yanked the steering position sensor. I had enough.
Out of time to work on it for now, but will get back to it when I can.
Pulled over at the nearest lot and took apart the dash and yanked the steering position sensor. I had enough.
Out of time to work on it for now, but will get back to it when I can.
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
Drove the car for a bit today and noticed a couple of times that the power randomly felt like it was dragged down and the car dove slightly to the right. I'm going to throw something out there...
Is it possible that this whole problem is a right front intermittent brake applying? What could cause it? Could the system would fault from that and amplify the problem?
This is extremely odd, since I have the steering position sensor disconnected. No warnings or anything of course, it just felt like the power was drug down and it pulled to the right like it use to when the system faulted out, only not as violent. Could it be the BCM?
Is it possible that this whole problem is a right front intermittent brake applying? What could cause it? Could the system would fault from that and amplify the problem?
This is extremely odd, since I have the steering position sensor disconnected. No warnings or anything of course, it just felt like the power was drug down and it pulled to the right like it use to when the system faulted out, only not as violent. Could it be the BCM?
Instructor
Joined: Feb 2007
Posts: 172
Likes: 2
From: Lafayette IN
Drove the car for a bit today and noticed a couple of times that the power randomly felt like it was dragged down and the car dove slightly to the right. I'm going to throw something out there...
Is it possible that this whole problem is a right front intermittent brake applying? What could cause it? Could the system would fault from that and amplify the problem?
This is extremely odd, since I have the steering position sensor disconnected. No warnings or anything of course, it just felt like the power was drug down and it pulled to the right like it use to when the system faulted out, only not as violent. Could it be the BCM?
Is it possible that this whole problem is a right front intermittent brake applying? What could cause it? Could the system would fault from that and amplify the problem?
This is extremely odd, since I have the steering position sensor disconnected. No warnings or anything of course, it just felt like the power was drug down and it pulled to the right like it use to when the system faulted out, only not as violent. Could it be the BCM?
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
This very thing happened to me driving down the highway...it was like i had a ghost applying the brakes but only the front left tire locked up. Determined it was the steering wheel position sensor. A simple $80 part and 3 hours of labor...problem fixed!! I haven't had any issues since installing this part.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
I don't think it would be the BCM. It should have no function except to be communicate information to the IPC/DIC. It would be more likely to be the EBCM in my opinion.
You could rule out everything else by also disconnecting the Yaw Rate sensor and the Lateral Accelerometer and see if it still happens.
You could rule out everything else by also disconnecting the Yaw Rate sensor and the Lateral Accelerometer and see if it still happens.
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Instructor
Joined: Feb 2007
Posts: 172
Likes: 2
From: Lafayette IN
Click on this link to a thread I started last May...it has some really good advise from several respected corvette forum members.
http://forums.corvetteforum.com/c5-t...need-help.html
http://forums.corvetteforum.com/c5-t...need-help.html
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
I don't think it would be the BCM. It should have no function except to be communicate information to the IPC/DIC. It would be more likely to be the EBCM in my opinion.
You could rule out everything else by also disconnecting the Yaw Rate sensor and the Lateral Accelerometer and see if it still happens.
You could rule out everything else by also disconnecting the Yaw Rate sensor and the Lateral Accelerometer and see if it still happens.
I'll disconnect them all, but it makes no sense that they would have any effect if the system is suppose to be entirely disabled with the removal of the Steering Position Sensor.
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
Click on this link to a thread I started last May...it has some really good advise from several respected corvette forum members.
http://forums.corvetteforum.com/c5-t...need-help.html
http://forums.corvetteforum.com/c5-t...need-help.html
I have it disconnected.
Please let me know if I'm missing something.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
I know it has been frustrating for you and the issue is a SAFETY
concern. I wish I had the magic bullet. Just trying to help rule things out so you can figure out what is going on.
I am not going to recommend anything I would not do if I had your issue. There is a reason for the issue and it can be found.
I teach and perform root cause analysis in the nuclear industry where millions of dollars are on the line. I could tell you stories where smart people have told me that COULD NEVER BE THE CAUSE. Made them do the test and I was proven correct. I never rule anything off the table that might cause an issue until we test or inspect to support or refute the theory. Most times in my business on a major issue it is not just one thing but several that line up in to allow the problem to occur. Like the magic bullet going thru 3 walls because the holes in the wall just happened to be aligned for the bullet trajectory.
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
Sounds good. They are easy to disconnect. I was looking for more of an explanation on what it could be doing, instead of pulling the sensors blindly (prefer to understand the bigger picture). I was under the impression this system would be defeated with it removed. Wish that were the case! Probably about time I coughed up the dough for a service manual. 
I'll yank them when I can. Will be a couple weeks before I can update though since I'll be traveling.
The 1/2 Mile event is coming up on the 21st. Would be great to at least get it eliminated 100% by then. Probably could just yank the EBCM during the event if I need to. Don't need ABS there...
Thanks guys.
I'll yank them when I can. Will be a couple weeks before I can update though since I'll be traveling. The 1/2 Mile event is coming up on the 21st. Would be great to at least get it eliminated 100% by then. Probably could just yank the EBCM during the event if I need to. Don't need ABS there...
Thanks guys.
Last edited by Quickshift_C5; Jun 2, 2014 at 07:29 PM.
Le Mans Master
Joined: Mar 2011
Posts: 6,835
Likes: 302
From: Columbia SC
If you pulled the 2 EBCM fuses you would not need to yank anything.
The FSM is of no help in cases like this. I don't know what the internal EBCM circuits are so I don't know what can fail inside and cause what to happen. We do know that AH should not work with the SWPS removed. Proven by many people to be effective. We also know that turning TC off should do it too. Something is causing an unwanted braking action. Only the EBCM can cause that. The Yaw sensor and the Lateral Accelerometer are the only other two AH related inputs to the EBCM.
I think the problem will still exist when you pull those 2 out of the circuit. However that would only leave the EBCM. We will not know until you do it.
The FSM is of no help in cases like this. I don't know what the internal EBCM circuits are so I don't know what can fail inside and cause what to happen. We do know that AH should not work with the SWPS removed. Proven by many people to be effective. We also know that turning TC off should do it too. Something is causing an unwanted braking action. Only the EBCM can cause that. The Yaw sensor and the Lateral Accelerometer are the only other two AH related inputs to the EBCM.
I think the problem will still exist when you pull those 2 out of the circuit. However that would only leave the EBCM. We will not know until you do it.
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
In getting the car ready for the 1/2 Mile Event coming up next weekend, I brought the car in to my friends at a local shop so we could get in on a lift and inspect it one final time. After, he hopped in the car with a Tech 2 and we did some hard driving while watching the sensors.
The lateral accelerometer never deviated from 0.0G...ever. I believe we may have found the culprit. And, as you guys suggested, we would have come across this in the next phase of the process of elimination.
I'm hopeful that IS the problem, and judging by the readouts (ALL other sensors reported correct information - except steering which is still disconnected) and that one NEVER changing...well, it sounds like a winner.
Going to try and locate a used one and test it out. Meanwhile, I'm out of time and will run the event next weekend with no traction or stability control. Should be fun!
The lateral accelerometer never deviated from 0.0G...ever. I believe we may have found the culprit. And, as you guys suggested, we would have come across this in the next phase of the process of elimination.
I'm hopeful that IS the problem, and judging by the readouts (ALL other sensors reported correct information - except steering which is still disconnected) and that one NEVER changing...well, it sounds like a winner.
Going to try and locate a used one and test it out. Meanwhile, I'm out of time and will run the event next weekend with no traction or stability control. Should be fun!
Thread Starter
Melting Slicks
Joined: Sep 2006
Posts: 2,728
Likes: 142
From: Iowa
