ABS, Traction Contol and Active Handling Light
Thread Starter
Intermediate
Joined: Aug 2007
Posts: 26
Likes: 0
From: Bristol VA
ABS, Traction Contol and Active Handling Light
Maybe someone can help. Yesterday my ABS, Active Handling and Traction Contol Light all come on at the same time. 02' ZO6 20,000 miles. I figure it is some kind of fault???
Tech Contributor
Joined: Oct 1999
Posts: 41,058
Likes: 9,821
From: Charlotte, NC (formerly Endicott, NY)
First thing to do is check the codes by Pushing and holding the options button while pressing the fuel button 4 times. The codes will show up on the DIC and you can report them here. Not all problems are EBCM fatal errors.
Bill
Bill
Burning Brakes
Joined: Jan 2006
Posts: 1,170
Likes: 27
From: Magnolia Greens NC
Here's Your Answer..
(I'll email pics if you PM me your email address)
Let's cover some basic information on AH, TC, and ABS. In simple terms, these three systems combine data from wheel speed sensors, yaw rate sensors, steering wheel position sensors, along with brake and throttle inputs to determine what the driver wants to do and detects any lose of traction and take corrective action by pulling back on the throttle, activating brakes on individual wheels, or releasing brake pressure as needed to maintain traction.
What goes wrong
When there is a problem anywhere in the system, the computer does not know what's going on with the car or cannot respond correctly. Rather than risking the wrong response which could potentially wreck you car, the whole system is simply disabled for the remainder of the ignition cycle. At this time you will see the ABS and Traction Control warning indicators illuminated on the instrument cluster along with the following messages on the Driver Information Center (DIC):
- Service ABS
- Service Traction System
- Service Active Handling
At this point, you can safely continue to drive your car, just remember that your electronic driving aids are no longer functioning so you should adjust your driving habits accordingly.
Troubleshooting
As I said before, when there is a problem the system is deactivated for the remainder of the ignition cycle, so sometimes everything will go back to normal if you just turn off the car and restart it. If that corrects the problem, it was either a glitch in the system, a lose connection that's going to come back soon or an early sign of a future failure that is coming. Even though the system is now functional it is still beneficial to continue to trouble shoot. The history code should give you a good idea of what to check
The next step is to see where the fault is. If you have several different codes write them down, clear them, and see which ones come back the next time you start the car. At this point, I'm betting that the codes point to either the EBCM or the wheel speed sensors. We'll get to the wheel speed sensors later, for now, let's get to the EBCM.
Electronic Brake Control Module
The most common code for the EBCM is C1214 - Sol Valve relay Contact or coil CKT Open. This code is set when the system voltage is less than 8 volts for 0.23 seconds. Since our goal is to fix this for the lowest price possible, we'll start checking things we can fix for free
The EBCM sits between the engine and radiator. You can see it in the picture on the left below. The EBCM is on the left with the large wire harness coming into it and the sticker on top. The Brake Pressure Modulator Valve (BPMV) in on the right with the brake lines coming out. The EBCM is a dry module, meaning that you can change it out without having to worry about bleeding the ABS system. All of the brake fluid is contained within the BPMV. The coils (seen in the picture on the right below) fit over small spools that have valves inside them. The valves are operated by an electromagnetic field supplied by the coils.
Start by doing a quick visual inspection of the wires. If there are any obvious signs of damage, you've likely found the problem. One member had a problem with the wires rubbing the serpentine belt
Also check to make sure the wire harness has a good connection. If the connection appears solid disconnect it (see step 3 in the replacement instructions below) check the pins to ensure that they have not been bent or damaged in any way. If there is any sign of corrosion, clean it off. Once everything looks good, reseat the harness.
Next, let's move on to the grounds. The EBCM is grounded to the chassis on the left frame rail, just forward of the engine. It's the Black box right in the middle of the picture. As you can see, it's real easy for dirt and moisture to get in that area which isn't exactly good for electronic components. Even if you never drive your car in the rain, it'll still get wet when you wash it, and that could be enough
Start by unbolting the chassis ground, then take the chassis ground connector apart.
These pictures show the corrosion that can build up in the ground connector. If you chassis grounds look like this one, you've probably found the problem. Even if they don't, go ahead and clean it up with a wire brush before putting it back together. Also clean off the chassis and bolt to make sure you've got a good clean ground.
*If you are having any other electrical issues, it's a good idea to check the grounds. These pictures show where the other grounds are.
It's unlikely, but before you break out you credit card and forking over your hard earned money, it's a good idea to check the fuses. One fuse box is located under the hood beside the battery, the second one is under the passenger side of the dash. Remove the floor mat and you will see the access panel. Just pull the fuses out and do a quick visual check.
On the left, you see a good fuse, on the right is a bad fuse
At this point, we know all of the wires are good, but for some reason enough voltage is not getting to the system. It is possible that your battery is not functioning properly. If your battery is a couple of years old, has been drained and recharged a couple of times it might be a good idea to go ahead and replace your battery. This is a long shot for EBCM issues, but I think it's worth a shot before spending several hundred dollars for a new EBCM and you're going to have to replace it eventually anyways. Old batteries can cause a variety of minor electrical issues and you likely have a bunch of history codes for minor issues if the battery is causing the problem.
Now on the EBCM itself. If the electrical contacts inside the relay are dirty or burnt, the vibration from striking the module may change the symptoms or may clear them up for a while. This is by no means a fix or a cure all, in fact it could make it worse or it may not do anything, it's just something to try. Use a small plastic hammer or something similar, lightly tap the front of the EBCM on the lower right corner of the module. The area will be on the right hand side of the lower electrical connection seen in the picture below.
At this point, You've got to additional possibilities. Replace the EBCM or replace both the EBCM and the BPMV. The service manual calls for you to measure the resistance between each pump motor control circuit and the housing of the BPMV, if that checks our okay, you replace the EBCM if not you replace them both. Since most people do not have the equipment to do this the best we can do is to replace the EBCM. If that doesn't work, you'll have to go back and replace the BPMV.
The procedure for replacing the EBCM is very simple. The only special tool you need is a T-20 torx screw driver. I have a Craftsman tool set that has a 1/4" drive screwdriver with and adapter for many different size bit. Unfortunately, the adapter was to long to fit between the EBCM and water pump, so I purchased a set of Craftsman 5 pc. torx screwdriver set that worked fine. A flathead screwdriver may also be needed to pry apart the EBCM from the BPMV
1 - make sure the car is off.
2 - you will probably need to remove the airbridge to get to the EBCM.
3 - remove the wire harness by first removing the white plastic clip that locks it in place (I cut it off and replaced it with a zip-tie) (picture 1), then lift gray handle and pull back on the wire harness (picture 3). At this point, you will be able to see the second wire connection that is removed by pulling down (picture 3).
4 - The service manual call for you the remove the 2 insulator nuts that hold the BPMV to the brackets and lift the EBCM/BPMV out of the bracket. I do not think this step is necessary because there is plenty of room while it is still in the bracket and you do not gain much additional clearance since the brake lines restrict the movement.
5 - Remove the 6 T-20 torx screws connecting the EBCM and BPMV - 1 on each corner and 2 on the sides (picture 2).
6 - "Separate the EBCM from the BPMV by gently pulling apart until separated" - I should start laughing here, but it's not that funny. It's been my experience that anytime the instructions call for you to do something gently, nothing gentle is going to work. In this case, I had to use a flathead screw driver to brake the seal. Once it moved a little, the rest was easy. In addition to the rubber seal, each of the 12 holes you see in picture 3 have a peg in them from the BPMV. Don't go crazy, but be prepared to force them apart.
7 - At this point, all you've got to do is put it all back together. push the new EBCM onto the BPMV.
8 - Replace the 6 T-20 torx screws
9 - reconnect the wire harness
10 - put the intake back on
picture 1 picture 2 picture 3
At this point, the AH/TC/ABS should work normally. If not, you've also got a problem with the BPMV. Although you could replace the BPMV yourself, you have to bleed the ABS system which requires Tech II. For those of you like me that don't have access to Tech II, you've got 2 options. Replace the BPMV yourself and tow the car to a shop with Tech II to have it bled, or just take it in to have the BPMV replaced. The advantage is that you've already done all of the trouble shooting so you want have to pay the mechanic to diagnose the problem for you.
Replacement part sources
New EBCMs. Below is a list of part #s and estimated prices from Fred Beans to give you an idea of what you should pay.
Part Number: 10343433
All 2003-2004: $465.58
Part Number: 12216561
All 2002: $610.16
Part Number: 12208997
All 2001: $612.80
Part Number: 9367071
All 1999-2000 w/o Control Active Brakes: $486.40
An alternative to buying a new one is to have your original rebuilt.
For EBCM repair/replace
Call Brandon
877-648-7530 at ABS FIXER
or: www.absfixer.com
$150. plus UPS....warranted as long as You own it
Let's cover some basic information on AH, TC, and ABS. In simple terms, these three systems combine data from wheel speed sensors, yaw rate sensors, steering wheel position sensors, along with brake and throttle inputs to determine what the driver wants to do and detects any lose of traction and take corrective action by pulling back on the throttle, activating brakes on individual wheels, or releasing brake pressure as needed to maintain traction.
What goes wrong
When there is a problem anywhere in the system, the computer does not know what's going on with the car or cannot respond correctly. Rather than risking the wrong response which could potentially wreck you car, the whole system is simply disabled for the remainder of the ignition cycle. At this time you will see the ABS and Traction Control warning indicators illuminated on the instrument cluster along with the following messages on the Driver Information Center (DIC):
- Service ABS
- Service Traction System
- Service Active Handling
At this point, you can safely continue to drive your car, just remember that your electronic driving aids are no longer functioning so you should adjust your driving habits accordingly.
Troubleshooting
As I said before, when there is a problem the system is deactivated for the remainder of the ignition cycle, so sometimes everything will go back to normal if you just turn off the car and restart it. If that corrects the problem, it was either a glitch in the system, a lose connection that's going to come back soon or an early sign of a future failure that is coming. Even though the system is now functional it is still beneficial to continue to trouble shoot. The history code should give you a good idea of what to check
The next step is to see where the fault is. If you have several different codes write them down, clear them, and see which ones come back the next time you start the car. At this point, I'm betting that the codes point to either the EBCM or the wheel speed sensors. We'll get to the wheel speed sensors later, for now, let's get to the EBCM.
Electronic Brake Control Module
The most common code for the EBCM is C1214 - Sol Valve relay Contact or coil CKT Open. This code is set when the system voltage is less than 8 volts for 0.23 seconds. Since our goal is to fix this for the lowest price possible, we'll start checking things we can fix for free
The EBCM sits between the engine and radiator. You can see it in the picture on the left below. The EBCM is on the left with the large wire harness coming into it and the sticker on top. The Brake Pressure Modulator Valve (BPMV) in on the right with the brake lines coming out. The EBCM is a dry module, meaning that you can change it out without having to worry about bleeding the ABS system. All of the brake fluid is contained within the BPMV. The coils (seen in the picture on the right below) fit over small spools that have valves inside them. The valves are operated by an electromagnetic field supplied by the coils.
Start by doing a quick visual inspection of the wires. If there are any obvious signs of damage, you've likely found the problem. One member had a problem with the wires rubbing the serpentine belt
Also check to make sure the wire harness has a good connection. If the connection appears solid disconnect it (see step 3 in the replacement instructions below) check the pins to ensure that they have not been bent or damaged in any way. If there is any sign of corrosion, clean it off. Once everything looks good, reseat the harness.
Next, let's move on to the grounds. The EBCM is grounded to the chassis on the left frame rail, just forward of the engine. It's the Black box right in the middle of the picture. As you can see, it's real easy for dirt and moisture to get in that area which isn't exactly good for electronic components. Even if you never drive your car in the rain, it'll still get wet when you wash it, and that could be enough
Start by unbolting the chassis ground, then take the chassis ground connector apart.
These pictures show the corrosion that can build up in the ground connector. If you chassis grounds look like this one, you've probably found the problem. Even if they don't, go ahead and clean it up with a wire brush before putting it back together. Also clean off the chassis and bolt to make sure you've got a good clean ground.
*If you are having any other electrical issues, it's a good idea to check the grounds. These pictures show where the other grounds are.
It's unlikely, but before you break out you credit card and forking over your hard earned money, it's a good idea to check the fuses. One fuse box is located under the hood beside the battery, the second one is under the passenger side of the dash. Remove the floor mat and you will see the access panel. Just pull the fuses out and do a quick visual check.
On the left, you see a good fuse, on the right is a bad fuse
At this point, we know all of the wires are good, but for some reason enough voltage is not getting to the system. It is possible that your battery is not functioning properly. If your battery is a couple of years old, has been drained and recharged a couple of times it might be a good idea to go ahead and replace your battery. This is a long shot for EBCM issues, but I think it's worth a shot before spending several hundred dollars for a new EBCM and you're going to have to replace it eventually anyways. Old batteries can cause a variety of minor electrical issues and you likely have a bunch of history codes for minor issues if the battery is causing the problem.
Now on the EBCM itself. If the electrical contacts inside the relay are dirty or burnt, the vibration from striking the module may change the symptoms or may clear them up for a while. This is by no means a fix or a cure all, in fact it could make it worse or it may not do anything, it's just something to try. Use a small plastic hammer or something similar, lightly tap the front of the EBCM on the lower right corner of the module. The area will be on the right hand side of the lower electrical connection seen in the picture below.
At this point, You've got to additional possibilities. Replace the EBCM or replace both the EBCM and the BPMV. The service manual calls for you to measure the resistance between each pump motor control circuit and the housing of the BPMV, if that checks our okay, you replace the EBCM if not you replace them both. Since most people do not have the equipment to do this the best we can do is to replace the EBCM. If that doesn't work, you'll have to go back and replace the BPMV.
The procedure for replacing the EBCM is very simple. The only special tool you need is a T-20 torx screw driver. I have a Craftsman tool set that has a 1/4" drive screwdriver with and adapter for many different size bit. Unfortunately, the adapter was to long to fit between the EBCM and water pump, so I purchased a set of Craftsman 5 pc. torx screwdriver set that worked fine. A flathead screwdriver may also be needed to pry apart the EBCM from the BPMV
1 - make sure the car is off.
2 - you will probably need to remove the airbridge to get to the EBCM.
3 - remove the wire harness by first removing the white plastic clip that locks it in place (I cut it off and replaced it with a zip-tie) (picture 1), then lift gray handle and pull back on the wire harness (picture 3). At this point, you will be able to see the second wire connection that is removed by pulling down (picture 3).
4 - The service manual call for you the remove the 2 insulator nuts that hold the BPMV to the brackets and lift the EBCM/BPMV out of the bracket. I do not think this step is necessary because there is plenty of room while it is still in the bracket and you do not gain much additional clearance since the brake lines restrict the movement.
5 - Remove the 6 T-20 torx screws connecting the EBCM and BPMV - 1 on each corner and 2 on the sides (picture 2).
6 - "Separate the EBCM from the BPMV by gently pulling apart until separated" - I should start laughing here, but it's not that funny. It's been my experience that anytime the instructions call for you to do something gently, nothing gentle is going to work. In this case, I had to use a flathead screw driver to brake the seal. Once it moved a little, the rest was easy. In addition to the rubber seal, each of the 12 holes you see in picture 3 have a peg in them from the BPMV. Don't go crazy, but be prepared to force them apart.
7 - At this point, all you've got to do is put it all back together. push the new EBCM onto the BPMV.
8 - Replace the 6 T-20 torx screws
9 - reconnect the wire harness
10 - put the intake back on
picture 1 picture 2 picture 3
At this point, the AH/TC/ABS should work normally. If not, you've also got a problem with the BPMV. Although you could replace the BPMV yourself, you have to bleed the ABS system which requires Tech II. For those of you like me that don't have access to Tech II, you've got 2 options. Replace the BPMV yourself and tow the car to a shop with Tech II to have it bled, or just take it in to have the BPMV replaced. The advantage is that you've already done all of the trouble shooting so you want have to pay the mechanic to diagnose the problem for you.
Replacement part sources
New EBCMs. Below is a list of part #s and estimated prices from Fred Beans to give you an idea of what you should pay.
Part Number: 10343433
All 2003-2004: $465.58
Part Number: 12216561
All 2002: $610.16
Part Number: 12208997
All 2001: $612.80
Part Number: 9367071
All 1999-2000 w/o Control Active Brakes: $486.40
An alternative to buying a new one is to have your original rebuilt.
For EBCM repair/replace
Call Brandon
877-648-7530 at ABS FIXER
or: www.absfixer.com
$150. plus UPS....warranted as long as You own it
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
C1214 is one of the "bad" ones ..... but there is good news too ...
You can take the car to the stealership and unless you have a warranty, the parts and labor to fix this (they replace the EBCM) will run +$1,000.00
Or, go to this website and send the unit in yourself ....
http://www.absfixer.com/
Note right at the top of the page they announce a fix for the Corvette C1214 ... pretty cool ....
You can take the car to the stealership and unless you have a warranty, the parts and labor to fix this (they replace the EBCM) will run +$1,000.00
Or, go to this website and send the unit in yourself ....
http://www.absfixer.com/
Note right at the top of the page they announce a fix for the Corvette C1214 ... pretty cool ....
Melting Slicks
Joined: Jul 2004
Posts: 2,340
Likes: 35
From: Folsom Lake CA
I had the same poblem, only intermittent, with my right front. It seemed like it only happened in either cold or damp conditions, but almost always after washing the car, even in the summer.
I cleaned the contact points at both ends of the jumper wiring harness that goes between the wheel sensor to the main harness just inside the frame rail. It worked for about 6 months, then came back.
I then wondered if the harnesses were interchangable side to side. I figured that I if they were, I would be able to determine whether or not it was really the jumper harness, I swapped it with my left jumper harness, and then the code showed up referring to my left side.
Although the part numbers are different, and no one this forum was able to tell me whether or the harnesses were interchangable or not, I figured I had nothing to lose and swapped the harnesses from side to side. Interestingly, the problem went away completely, and it's been three years.
My summation is that the contacts were not seating properly, and the swap probably enabled the contacts on the harness to meet more soldily. Before you try anything else, I would try this, as electrical connections are more often than not the root cause of computer-generated errors in these types of cars, and this was a simple (albeit lucky) fix for me, and it may indeed be for you, too.
I cleaned the contact points at both ends of the jumper wiring harness that goes between the wheel sensor to the main harness just inside the frame rail. It worked for about 6 months, then came back.
I then wondered if the harnesses were interchangable side to side. I figured that I if they were, I would be able to determine whether or not it was really the jumper harness, I swapped it with my left jumper harness, and then the code showed up referring to my left side.
Although the part numbers are different, and no one this forum was able to tell me whether or the harnesses were interchangable or not, I figured I had nothing to lose and swapped the harnesses from side to side. Interestingly, the problem went away completely, and it's been three years.
My summation is that the contacts were not seating properly, and the swap probably enabled the contacts on the harness to meet more soldily. Before you try anything else, I would try this, as electrical connections are more often than not the root cause of computer-generated errors in these types of cars, and this was a simple (albeit lucky) fix for me, and it may indeed be for you, too.
Last edited by MrLeadFoot; Sep 3, 2007 at 11:48 PM.
3rd Gear
Joined: Sep 2007
Posts: 3
Likes: 0
would very much appreciate the pictures that you talk about in this post. E-mail address is doctrjoyce@hotmail.com appreciate the help. tom
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Burning Brakes
Joined: Jan 2006
Posts: 1,170
Likes: 27
From: Magnolia Greens NC
would very much appreciate the pictures that you talk about in this post. E-mail address is doctrjoyce@hotmail.com appreciate the help. tom
Team Owner
Joined: May 2003
Posts: 23,480
Likes: 9
From: East Meadow NY
St. Jude Donor '12
C1214 is one of the "bad" ones ..... but there is good news too ...
You can take the car to the stealership and unless you have a warranty, the parts and labor to fix this (they replace the EBCM) will run +$1,000.00
Or, go to this website and send the unit in yourself ....
http://www.absfixer.com/
Note right at the top of the page they announce a fix for the Corvette C1214 ... pretty cool ....
You can take the car to the stealership and unless you have a warranty, the parts and labor to fix this (they replace the EBCM) will run +$1,000.00
Or, go to this website and send the unit in yourself ....
http://www.absfixer.com/
Note right at the top of the page they announce a fix for the Corvette C1214 ... pretty cool ....
EDIT: It took me at most an 1hr to get the EBCM out. It is a little tight and I didn't have a T-20 screw driver so I had to mess around with ratchets + extensions + t-20 bits. It was much faster going back in.
Bill T (above) email was a great help.
Last edited by chaase; Sep 4, 2007 at 04:50 PM.
Racer
Joined: Sep 2007
Posts: 406
Likes: 0
From: Walnut Creek California
I as well would LOVE to have the pics. Your step by step instructions make it sound easy and not intimidating. Hopefully this is something I can do on my own. Thanks for the awesome info. I can't wait to see that light go off on my car.
Email is: medhorse@gmail.com
Thanks!
Email is: medhorse@gmail.com
Thanks!
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
Bill Dearborn's post above tells how to display codes.
Racer
Joined: Jun 2003
Posts: 256
Likes: 0
From: Newport Beach Ca
2nd Gear
Joined: Aug 2007
Posts: 2
Likes: 0
I had Brandon w/absfixed repair my module four weeks ago. I had to clear the codes & cycle thru the ignition switch three times to clear everything. So far no more problems in my 2k coupe. Cost me under$200 compared to the dealers quote of $1200 plus labor.
Safety Car
Joined: Aug 2000
Posts: 4,933
Likes: 30
From: San Rafael CA
I'm confused ... so to sks ..... could you please clarify your question ....
What do you mean by "service light" ???
Are you getting a message on the DIC when you turn it off that says SERVICE in it ???
Or are you seeing the yellow warning light on the gauge panel ???
We're confused ...... this is probably just a case of RTFM.
Last edited by BlackZ06; Sep 6, 2007 at 04:54 PM.
Instructor
Joined: Apr 2006
Posts: 119
Likes: 0
From: Los Angeles CA
Originally I took the post the way MrLeadFoot did .. I read it as he was getting a "SERVICE" message. But then I read Bruceatlam's post and realized that it may well be the guy is simply seeing the warning light on the gauges, which as Bruce points out is normal behaviour.
I'm confused ... so to sks ..... could you please clarify your question ....
What do you mean by "service light" ???
Are you getting a message on the DIC when you turn it off that says SERVICE in it ???
Or are you seeing the yellow warning light on the gauge panel ???
We're confused ...... this is probably just a case of RTFM.
I'm confused ... so to sks ..... could you please clarify your question ....
What do you mean by "service light" ???
Are you getting a message on the DIC when you turn it off that says SERVICE in it ???
Or are you seeing the yellow warning light on the gauge panel ???
We're confused ...... this is probably just a case of RTFM.
I am getting a message telling me that the ABS and Traction Control System needs to be serviced. I do not know if the car comes with Active Handling (just bought it) and did not see that message.
Of course i see the yellow traction light on the gauge panel with the traction control off.
I just find it odd that the service message comes on when the traction control button is turned off. Should it notify me with the traction control is on? I will pull codes and post. I apologize as i have no manual. Thanks.
Last edited by sks; Sep 7, 2007 at 05:36 PM.
Thread Starter
Intermediate
Joined: Aug 2007
Posts: 26
Likes: 0
From: Bristol VA
