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Old Aug 16, 2007 | 01:01 PM
  #1  
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Default Active Handling Module

Where is it located and what is the fuse number for it on the fuse block? After my TTi X Kit install seems like I get the Warming up and Service the Active handling system. I want to check the wires and make sure everything is connected and tight.

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The Big Dog
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Old Aug 16, 2007 | 01:10 PM
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What other messages do you get? Service ABS, Service Traction Control?? Check for failure codes on the DIC to help locate the problem (press and hold options while pushing fuel 4 times to access the On Board Diagnostics). The Active Handling is a function of the ABS system. The Electronic Brake Control Module (EBCM) and Brake Pressure Modulator Valve (BPMV) are co-located just in front of the engine on the drivers side of the car. If you look to the outboard side and down from the power steering reservoir you will see them.

Bill
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Old Aug 17, 2007 | 07:32 PM
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Bill,

Thanks for the info. For now I have cleared all the codes I want to drive it and see which ones come back up. My feeling is that the tunner didnt clear the codes that were thrown during the install. I did record 2 codes from the TCS C1283 and C1255. Got any ideas on these?

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The Big Dog
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Old Aug 17, 2007 | 11:07 PM
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Originally Posted by TheBigDog
Bill,

Thanks for the info. For now I have cleared all the codes I want to drive it and see which ones come back up. My feeling is that the tunner didnt clear the codes that were thrown during the install. I did record 2 codes from the TCS C1283 and C1255. Got any ideas on these?

Thanks,
The Big Dog
http://www.corvettedoctor.com/2004_DTC_Codes_Page2.html

Sounds like your speed sensors (1283) and ECU Malfunction (1255). The service manual has detailed steps to follow, but to long to type. Maybe somebody with electronic version will post up.
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Old Aug 18, 2007 | 12:32 AM
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C1283 indicates there is a problem with the steering wheel centering. C1255 indicates there is an internal EBCM problem. When the kit was installed was the steering shaft disconnected from the steering rack? If so the steering wheel may have been turned 360 degrees before the shaft was reconnected to the rack and may be causing C1283. Once that is solved the other problem might go away. If not then you will need to check the wiring going to the EBCM or it may be time for a new EBCM.

Bill
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Old Aug 18, 2007 | 07:45 AM
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Default Here's Help IF You Need It...

(if you would like the pictures, PM me your email address)
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



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
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Old Aug 18, 2007 | 03:50 PM
  #7  
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Originally Posted by Bill Dearborn
C1283 indicates there is a problem with the steering wheel centering. C1255 indicates there is an internal EBCM problem. When the kit was installed was the steering shaft disconnected from the steering rack? If so the steering wheel may have been turned 360 degrees before the shaft was reconnected to the rack and may be causing C1283. Once that is solved the other problem might go away. If not then you will need to check the wiring going to the EBCM or it may be time for a new EBCM.

Bill
Bill,

I reset the codes and the only one that came back is the c1283. I tend to agree with you that the steering wheel maybe be 360* out and causing the codes.

Thanks,
Greg
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