Active handling goes nutz!! Almost causes accident...
02-02-2009, 01:15 PM
#1
Melting Slicks
Thread Starter
Active handling goes nutz!! Almost causes accident...
So I'm entering the highway on my way to work, and I get in the left lane to accelerate past a really slow merger... I'm going about 50 when all of a sudden, my nose starts to pull really hard to the right and the vehicle slows way down. The DIC is flashing Active Handling at me as I attempt to get control of the vehicle. I was unable to prevent the car from changing lanes, but I managed to get all the way over to the shoulder and stop without getting hit.
I switch off active handling, and away I go. My EBCM was rebuilt by ABS Fixer last year and I haven't had any problems with it since (before that was getting the ole' C1214 code). I've heard people claim that their AH went crazy causing an accident, but didn't know whether to believe it or not. Thankfully there wasn't a whole lot of traffic on the road, otherwise, I'd have hit someone for sure. Thank God I hadn't gotten up to full highway speed yet -- don't know if I could have kept control at 70 MPH versus 50...
Any thoughts on what is wrong? I'm sort of afraid to turn the AH back on unless I'm in a huge parking lot with nothing to hit anywhere near me.
I switch off active handling, and away I go. My EBCM was rebuilt by ABS Fixer last year and I haven't had any problems with it since (before that was getting the ole' C1214 code). I've heard people claim that their AH went crazy causing an accident, but didn't know whether to believe it or not. Thankfully there wasn't a whole lot of traffic on the road, otherwise, I'd have hit someone for sure. Thank God I hadn't gotten up to full highway speed yet -- don't know if I could have kept control at 70 MPH versus 50...
Any thoughts on what is wrong? I'm sort of afraid to turn the AH back on unless I'm in a huge parking lot with nothing to hit anywhere near me.
02-02-2009, 01:36 PM
#3
Drifting
How much tread left on the Rear tires compared to the Front?
Had almost the same situation, turned out to be the overall diameter difference between Front and Rear tires was below .5 inches. The active handling kicks in, thinking somethings wrong, due to the difference not being greater than .5 inches. Can be very scary at highway speeds.
Had almost the same situation, turned out to be the overall diameter difference between Front and Rear tires was below .5 inches. The active handling kicks in, thinking somethings wrong, due to the difference not being greater than .5 inches. Can be very scary at highway speeds.
02-02-2009, 02:26 PM
#4
Melting Slicks
I'd be willing to bet that when you check the codes, C1287 and/or C1288 will show. The steering positioning sensor will need to be replaced.
http://forums.corvetteforum.com/c5-t...on-sensor.html
http://forums.corvetteforum.com/c5-t...on-sensor.html
02-02-2009, 02:43 PM
#5
Melting Slicks
wow. this is good info to know. I just replaced 2 tires because my rears needed it but the fronts still have a few months left in them. scared me for a minute. but since the rears had to go first then my rears should still be a good amount bigger than the front tires.
02-02-2009, 04:10 PM
#6
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Vaughn
Thanks for serving brother!
Like it was previously suggested, pull and post the DTCs.
Remember,,,,the EBTCM DTCs reset them selves when you turn the ignition off so, when the system acts up, read the DTCs then or before you shut it down. Hows your alignment? If your steering wheel is way off center, it can cause some weird AH issues.
My 02 Z had an issue where it applied the brake in a pulsating even event on all four wheels when we were driving down a straight level road. My issue turned out to be a bad EBTCM. The microprocessor inside the EBTCM goes bad. I got GM to replace it under warranty and the issue has never returned. If thats what wrong with yours, no one can fix it so, start saving that hazordious duty pay and get a new one from Gene Culley!
Thanks for serving brother!
Like it was previously suggested, pull and post the DTCs.
Remember,,,,the EBTCM DTCs reset them selves when you turn the ignition off so, when the system acts up, read the DTCs then or before you shut it down. Hows your alignment? If your steering wheel is way off center, it can cause some weird AH issues.
My 02 Z had an issue where it applied the brake in a pulsating even event on all four wheels when we were driving down a straight level road. My issue turned out to be a bad EBTCM. The microprocessor inside the EBTCM goes bad. I got GM to replace it under warranty and the issue has never returned. If thats what wrong with yours, no one can fix it so, start saving that hazordious duty pay and get a new one from Gene Culley!
Last edited by Bill Curlee; 02-07-2009 at 09:07 AM.
02-02-2009, 04:52 PM
#7
Melting Slicks
Thread Starter
Vaughn
Thanks for serving brother!
Like it was previously suggested, pull and post the DTCs.
Remember,,,,the EBTCM DTCs reset them selves when you turn the ignition off so, when the system acts up, read the DTCs then or before you shut it down. Hows your alignment? If your steering wheen is way off center, it can cause some weird AH issues.
My 02 Z had an issue where it applied the brake in a pulsating even event on all four wheels when we were driving down a straight level road. My issue turned out to be a bad EBTCM. The microprecessor inside the EBTCM goes bad. I got GM to replace it under warrenty and the issue has never returned. If thats what wrong with yours, no one can fix it so, start saving that hardious duty pay and get a new one from Gene Culley!
Thanks for serving brother!
Like it was previously suggested, pull and post the DTCs.
Remember,,,,the EBTCM DTCs reset them selves when you turn the ignition off so, when the system acts up, read the DTCs then or before you shut it down. Hows your alignment? If your steering wheen is way off center, it can cause some weird AH issues.
My 02 Z had an issue where it applied the brake in a pulsating even event on all four wheels when we were driving down a straight level road. My issue turned out to be a bad EBTCM. The microprecessor inside the EBTCM goes bad. I got GM to replace it under warrenty and the issue has never returned. If thats what wrong with yours, no one can fix it so, start saving that hardious duty pay and get a new one from Gene Culley!
OUCH!!!
Still at work (22:37 my time) so haven't been able to check codes yet... Tires are pretty new (stock sizes - maybe 2000 miles on them)... Tread should be fine -- I drive fast here in Italy, but I really haven't done any burnouts. 
Alignment seems fine - haven't noticed any pulling at all... Until the EXTREME pull to the right today.
Originally Posted by cdnguyred88
Can be very scary at highway speeds.
Originally Posted by YeloFvr
I'd be willing to bet that when you check the codes, C1287 and/or C1288 will show. The steering positioning sensor will need to be replaced.
02-02-2009, 06:35 PM
#8
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I'd be willing to bet that when you check the codes, C1287 and/or C1288 will show. The steering positioning sensor will need to be replaced.
http://forums.corvetteforum.com/c5-t...on-sensor.html
http://forums.corvetteforum.com/c5-t...on-sensor.html
The thing is, the SWPS doesn't always err quite enough to throw a code and shut the system off, and that's probably what happened here...sometimes it simply causes active handling to jump in and hit the brakes. (in the eyes of the diagnostics, a normal event...Active handling "saved you"...no code thrown).
It's happened to me too. It's not a very comfortable feeling when you're driving perfectly straight on the freeway, nice sunny day, and your car suddenly decides to hit the brakes (on one side only) for no reason.
The system will disable itself when a code is thrown. it's when no code is thrown but the system goes into action unexpectedly, that's the bigger problem here.
It is for that reason I no longer use Active Handling, ever. Haven't in years. I trust myself to control the car a LOT more than I'll ever trust the integrity of the numerous sensors needed to make the system function.
Great system when it works...but beware of the day it doesn't. It's only a matter of time before this "safety feature" causes a serious wreck. And I know for sure is it won't be mine.
02-02-2009, 07:07 PM
#9
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It happened to me as well!! I installed four new tires but left stock size in front and went from 27540 to 27535 in the back it took about two months but all of a sudden my active handling started kicking in at 50. My mechanic had seen it before but to be sure he switched out my tires the stock ones on his vette, Problem solved. Cost me two new tires though!!!
02-02-2009, 07:47 PM
#10
Melting Slicks
Thread Starter
If it didn't disengage AH and throw a "service active handling" message, there will be no code to be found. But I agree that sensor is the likely culprit.
The thing is, the SWPS doesn't always err quite enough to throw a code and shut the system off, and that's probably what happened here...sometimes it simply causes active handling to jump in and hit the brakes. (in the eyes of the diagnostics, a normal event...Active handling "saved you"...no code thrown).
It's happened to me too. It's not a very comfortable feeling when you're driving perfectly straight on the freeway, nice sunny day, and your car suddenly decides to hit the brakes (on one side only) for no reason.
The system will disable itself when a code is thrown. it's when no code is thrown but the system goes into action unexpectedly, that's the bigger problem here.
It is for that reason I no longer use Active Handling, ever. Haven't in years. I trust myself to control the car a LOT more than I'll ever trust the integrity of the numerous sensors needed to make the system function.
Great system when it works...but beware of the day it doesn't. It's only a matter of time before this "safety feature" causes a serious wreck. And I know for sure is it won't be mine.
The thing is, the SWPS doesn't always err quite enough to throw a code and shut the system off, and that's probably what happened here...sometimes it simply causes active handling to jump in and hit the brakes. (in the eyes of the diagnostics, a normal event...Active handling "saved you"...no code thrown).
It's happened to me too. It's not a very comfortable feeling when you're driving perfectly straight on the freeway, nice sunny day, and your car suddenly decides to hit the brakes (on one side only) for no reason.
The system will disable itself when a code is thrown. it's when no code is thrown but the system goes into action unexpectedly, that's the bigger problem here.
It is for that reason I no longer use Active Handling, ever. Haven't in years. I trust myself to control the car a LOT more than I'll ever trust the integrity of the numerous sensors needed to make the system function.
Great system when it works...but beware of the day it doesn't. It's only a matter of time before this "safety feature" causes a serious wreck. And I know for sure is it won't be mine.
If I weren't in the Navy (and therefore prohibited from the outside practice of law), I'd file a class-action lawsuit against GM in a SECOND!!How many people have died in wrecks caused by this very defect? At full highway speed with just moderate traffic, I'd have wrecked for sure, and be lucky to survive... Fortunately, I wasn't up to speed yet, and there was very little traffic. And if the SWPS failure isn't enough to throw a code, GM could claim driver error, not design defect, caused the accident. If the driver dies, there's nothing to disprove GM's claim. Even if the code was thrown, if it resets when the ignition is turned off, again GM gets to claim operator error... SHEESH!!! I can just see me driving the Amalfi coast (which I did in the fall -- AMAZING!!!) and AH kicking in when it wasn't supposed to and I launch off a cliff to my death... Everyone would think (except for those that have ridden with me and know that I'm an excellent driver) that it was my own recklessness that caused my death... MAN, my blood is boiling over this!! I have a wife and 3 small children!!! I switched to Vettes from motorcycles thinking they'd be safer...
I remember very distinctly a couple years ago, someone on this forum claimed to have had a very serious accident (or perhaps it was his friend) as a result of the AH going haywire like mine did today. No one at the time mentioned anything like it was possible, in fact the opposite result occured in the thread -- most of the replies came from posters accusing the driver of being at fault and some even suggested he created the thread to try to cover up his own negligence in his dispute with the insurance company or GM... I didn't say anything in the thread because I had nothing to add or detract (other than my own hope that it wasn't a likely scenario).
Looks like I'll be joining the no AH driving club. I drove for 2 years without it anyway (before finally sending my EBCM to ABS Fixer)... Never once had any problem in those 2 years...
02-02-2009, 07:55 PM
#11
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If you do continue to use it, as stated above, you will find the system will most likely eventually start throwing C1287/1288 codes. (SWPS).
I have not stated that AH has ever caused an accident (nor do I know of any case that it may have been a factor)...but based on mine (and yours) personal experience, I think it's safe to say we know the potential is certainly there, and anyone that can comprehend that should stop and think about it.
Also, if you do throw an AH code, and the system shuts down while driving...as Bill said, the next time you start the car, although the AH system will come back to life, the code that caused it to previously shut it down will remain stored as a history code, it does not clear itself. So in that event, yes there would be some evidence of the trouble occurring.
I have not stated that AH has ever caused an accident (nor do I know of any case that it may have been a factor)...but based on mine (and yours) personal experience, I think it's safe to say we know the potential is certainly there, and anyone that can comprehend that should stop and think about it.
Also, if you do throw an AH code, and the system shuts down while driving...as Bill said, the next time you start the car, although the AH system will come back to life, the code that caused it to previously shut it down will remain stored as a history code, it does not clear itself. So in that event, yes there would be some evidence of the trouble occurring.
02-02-2009, 08:08 PM
#12
Race Director
So I'm entering the highway on my way to work, and I get in the left lane to accelerate past a really slow merger... I'm going about 50 when all of a sudden, my nose starts to pull really hard to the right and the vehicle slows way down. The DIC is flashing Active Handling at me as I attempt to get control of the vehicle. I was unable to prevent the car from changing lanes, but I managed to get all the way over to the shoulder and stop without getting hit.
I switch off active handling, and away I go. My EBCM was rebuilt by ABS Fixer last year and I haven't had any problems with it since (before that was getting the ole' C1214 code). I've heard people claim that their AH went crazy causing an accident, but didn't know whether to believe it or not. Thankfully there wasn't a whole lot of traffic on the road, otherwise, I'd have hit someone for sure. Thank God I hadn't gotten up to full highway speed yet -- don't know if I could have kept control at 70 MPH versus 50...
Any thoughts on what is wrong? I'm sort of afraid to turn the AH back on unless I'm in a huge parking lot with nothing to hit anywhere near me.
I switch off active handling, and away I go. My EBCM was rebuilt by ABS Fixer last year and I haven't had any problems with it since (before that was getting the ole' C1214 code). I've heard people claim that their AH went crazy causing an accident, but didn't know whether to believe it or not. Thankfully there wasn't a whole lot of traffic on the road, otherwise, I'd have hit someone for sure. Thank God I hadn't gotten up to full highway speed yet -- don't know if I could have kept control at 70 MPH versus 50...
Any thoughts on what is wrong? I'm sort of afraid to turn the AH back on unless I'm in a huge parking lot with nothing to hit anywhere near me.
I posted a long post about ut cant find it now.
Eventually the system did start throwing codes and they were a little misleading.
I finally caved and decided to remove the bits and peices to send to ABSFixer, that swhen I found the cause of all my issues (nd I too had the car grab a fist full of one front brake almost sending me under a semi one day).
The interconnect between the ABS pump setup and the EBCM had cracked and was making intermittent contact.
I fixed the interconnect plug cleaned ou tthe contacts etc (they had ogt oily and dirty) and the problem went away.
02-05-2009, 02:01 PM
#14
Melting Slicks
Thread Starter
Here's a link to a writeup about the C5 Active Handling system. Scan down to the highlighted section about the Yaw Rate Sensor.
http://www.corvetteactioncenter.com/...ehandling.html
http://www.corvetteactioncenter.com/...ehandling.html
02-05-2009, 02:30 PM
#15
Tech Contributor
WOW ! Thats crazy ! I always drive my car in comp mode (only traction control disabled). Guess I need to re-think that.
Toque
Toque
02-05-2009, 03:13 PM
#16
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WOW!!! If I weren't in the Navy (and therefore prohibited from the outside practice of law), I'd file a class-action lawsuit against GM in a SECOND!!
How many people have died in wrecks caused by this very defect? At full highway speed with just moderate traffic, I'd have wrecked for sure, and be lucky to survive... Fortunately, I wasn't up to speed yet, and there was very little traffic. And if the SWPS failure isn't enough to throw a code, GM could claim driver error, not design defect, caused the accident. If the driver dies, there's nothing to disprove GM's claim. Even if the code was thrown, if it resets when the ignition is turned off, again GM gets to claim operator error... SHEESH!!! I can just see me driving the Amalfi coast (which I did in the fall -- AMAZING!!!) and AH kicking in when it wasn't supposed to and I launch off a cliff to my death... Everyone would think (except for those that have ridden with me and know that I'm an excellent driver) that it was my own recklessness that caused my death... MAN, my blood is boiling over this!! I have a wife and 3 small children!!! I switched to Vettes from motorcycles thinking they'd be safer...
I remember very distinctly a couple years ago, someone on this forum claimed to have had a very serious accident (or perhaps it was his friend) as a result of the AH going haywire like mine did today. No one at the time mentioned anything like it was possible, in fact the opposite result occured in the thread -- most of the replies came from posters accusing the driver of being at fault and some even suggested he created the thread to try to cover up his own negligence in his dispute with the insurance company or GM... I didn't say anything in the thread because I had nothing to add or detract (other than my own hope that it wasn't a likely scenario).
Looks like I'll be joining the no AH driving club. I drove for 2 years without it anyway (before finally sending my EBCM to ABS Fixer)... Never once had any problem in those 2 years...
If I weren't in the Navy (and therefore prohibited from the outside practice of law), I'd file a class-action lawsuit against GM in a SECOND!!How many people have died in wrecks caused by this very defect? At full highway speed with just moderate traffic, I'd have wrecked for sure, and be lucky to survive... Fortunately, I wasn't up to speed yet, and there was very little traffic. And if the SWPS failure isn't enough to throw a code, GM could claim driver error, not design defect, caused the accident. If the driver dies, there's nothing to disprove GM's claim. Even if the code was thrown, if it resets when the ignition is turned off, again GM gets to claim operator error... SHEESH!!! I can just see me driving the Amalfi coast (which I did in the fall -- AMAZING!!!) and AH kicking in when it wasn't supposed to and I launch off a cliff to my death... Everyone would think (except for those that have ridden with me and know that I'm an excellent driver) that it was my own recklessness that caused my death... MAN, my blood is boiling over this!! I have a wife and 3 small children!!! I switched to Vettes from motorcycles thinking they'd be safer...
I remember very distinctly a couple years ago, someone on this forum claimed to have had a very serious accident (or perhaps it was his friend) as a result of the AH going haywire like mine did today. No one at the time mentioned anything like it was possible, in fact the opposite result occured in the thread -- most of the replies came from posters accusing the driver of being at fault and some even suggested he created the thread to try to cover up his own negligence in his dispute with the insurance company or GM... I didn't say anything in the thread because I had nothing to add or detract (other than my own hope that it wasn't a likely scenario).
Looks like I'll be joining the no AH driving club. I drove for 2 years without it anyway (before finally sending my EBCM to ABS Fixer)... Never once had any problem in those 2 years...
Bill
Last edited by Bill Dearborn; 02-05-2009 at 03:16 PM.
02-05-2009, 07:23 PM
#17
Great!
Now I got one more thing to worry about on my 200k mile DD. Things are starting to fail 1 by 1 these day's but I'm pretty diligent about fixing things as they break. I drive 100 miles a day, mostly freeway in the SF bay area, average speed is usually 75, given traffic conditions around here I'm seriously thinking about shutting off the active handling every time I get in the car now.
02-06-2009, 10:06 AM
#18
Race Director
It looks like we should all hit the AH button the instant something like this happens. I believe some of the older C5s cannot do this while moving? My 01 can and that's what I'll do should this happen to me. That IS scarry!
02-06-2009, 10:27 AM
#19
I hit everything off as soon as I start up ever since I was going hot into a turn on an cloverleaf once and it all came on and I nearly wrecked the car cause the computer was telling me I couldn't do what I was doing. Have had it all turned off always since then...dont want it..dont need it..
02-06-2009, 10:34 AM
#20
oh great!
How much tread left on the Rear tires compared to the Front?
Had almost the same situation, turned out to be the overall diameter difference between Front and Rear tires was below .5 inches. The active handling kicks in, thinking somethings wrong, due to the difference not being greater than .5 inches. Can be very scary at highway speeds.
Had almost the same situation, turned out to be the overall diameter difference between Front and Rear tires was below .5 inches. The active handling kicks in, thinking somethings wrong, due to the difference not being greater than .5 inches. Can be very scary at highway speeds.
tire wear is a bit off! crazy!