JetJazz

After having a Service ABS/Traction Control indication I found out after having the car put on a Tech II that the ABS module is bad. Are these modules interchangeable or are they specific to each C5 year?
The estimate I was given for the repair was $750.00. Is the replacement of the ABS module a do-it-yourself job?

Thanks for any advice.

JetJazz

Heretic

This is not gospel, but I have gathered that 97-98, 99-2000, 2001-2004 are different from one another. Also if you have active handling thats another difference.

There are two parts to the abs/TSC system, the computer part (ebtcm) and the mechanical part (the pump and valves) these are separate even though they are mounted together. Fred Beans (a site sponsor) sells the 99-2000 ebtcm for 400 or so. It would not be hard to install it yourself, I don't think you break the seals on the hyraulics.

Also check the forum for the posts on grounds, many ABS problems are getting traced back to bad grounds.

Motorhead5673

I've been working on restoring a theft recovery 99 C5 and I can tell you that most likely each year is different and like previously mentioned there is even a difference within the year model depending if you car had the "Active Brake(or handling)" Control option. You can tell if your car had this option if both brake lines run from the master cylinder to a common proportioning valve (at least on the 99 model). If you can live with a used unit try car-part.com.

JetJazz

Thanks guys! My vette is a 2000 coupe and it does not have Active Handling. If I may ask a dumb question....what does the module itself look like? I have worked on cleaning all the grounds but I will go back and do that again to make sure. The Service ABS, Service Traction Control indication does not come on every time, I'd say about every five starts or so the indication does not come on.

Thanks!!

JetJazz

Motorhead5673

On the 00 C5 is is mounted to the left front of the engine on a bracket mounted on the front sub frame. The pump and computer are all one unit. I've never taken one apart so that's all I can offer.

Does the ABS light come on during braking or normal driving without braking?

JetJazz

in normal driving the light is on but just a few minutes ago I went out for a drive and the light did not come on which happens a lot.

fdxpilot

Well, admittedly, I have an 02, which came with AH standard. But, I had the same indications. Occasional ABS, TC, and AH inop messages. I could shut it down, try again, and they would be gone. After a couple of weeks, the warnings became more frequent, and then became full time. I checked my DIC codes and got a C1214. Took it to the dealer (extended warranty,) and it turned out to be a BPMV (Brake Pressure Modulating Valve, I think). Thats the Valve and pump side of the assembly. If you're sure one of the two modules is the problem, replacing them is not too hard. They are expensive parts, though. Getting them from Ken Fichtner Chevy or Fred Beans will be much cheaper than from your local dealer.Check your codes and post them for us, and we may be able to offer better advice.

JetJazz

Here are the codes: C1243 H, C1255 H, U 1160 H

JR_VET

C1243 BPMV MOTOR Stalled See page 5-166 on service manual 1 of 3
C1255 EBTCM Internal Malfunction See page 5-172 of Service manual 1 of 3
U1160 Loss of Communication with LDCM (Left Door Control Module)
Trouble shooting aide on Page 8-50 of service maual 3 of 3
I know that some of the true motor heads will chime in and have already solved the problem but after reading some of the previous threads I believe they have hit your problem on the head. Change the BPMV and you should stop the confusion with C1255 and gain comm with LDCM.

Bill Curlee

Ok,,,,,,,,,,you asked for it! Here are some pictures of EBTCMs on a couple of cars that I have worked on. One of them was my Z06.

Here is the EBTCM on my 02 Z06:



It lives on the inboard side, in the thing directly below the rardiator hose in the picture.




Inside my EBTCM>



I have tons more pictures that I can e-mail you.

BC

Bill Curlee

C1243 BPMV MOTOR Stalled See page 5-166 on service manual 1 of 3
C1255 EBTCM Internal Malfunction See page 5-172 of Service manual 1 of 3

Those are NOT good news DTC codes! The most that you can do is make sure that the EBTCM ground wire is good and sound! If the ground wire is connected properly, I'm afraid that you will need to service the entire unit pump, motor and module! I would NOT want that repair bill!!

Here is where the ground wire for your Fronted Mounted EBTCM lives.





Remove the nut that secures the ground connector (Chassis Ground G-101) to the stud (use plenty of WD-40) and you will see a single ground wire eyelet. Clean wvwrything up with a wire brush and reassemble.



The ground wire/eyelet to the left is the ground wire for the EBTCM.

Clean it and reconnect the connector to the stud.

I would also disconnect the main connector on the module, inspect the connection and reconnect it. After you do all that, see what happens.

Bill

JetJazz

Bill,
The dealership has indicated from the TECH ll that it's just the module and a cost of $750 to repair.

Bill Curlee

Replacing the module is a cake walk!! One plug, four screws and it's out! 30 mins max!! You do NOT need to do any sort of programming! It a plug and play module. They are year and model speciffic. You want to make very sure that you tell Fred Bean or Fichners exactly what you have or dont have as options i.e. Active Handling.

BC

Bill Curlee

If it is intermittent, I would look else where before I replaced the module. Remove the module and take a look at the connections in the module and the plug connector. It's worth the cost of a new module to take a free look see!

Maybe you will find a smoking gun.

Let me send you a schematic and point you to a few places to look first. (SEE E-MAIL) Check out the schematic and the trouble shooting procedures on the pages below it.

While you have the Chassis ground connector disassembled, I want you to completely field strip the ground connector down and clean the male and female pins on the inside. Mine had significant corrosion on the inside and caused a **** load of DTC codes and electrical issues!





See the corrosion!!!! YUK!!!!



The area where the screw driver is pointing is where the retainer clips that hold the male and female sides of the connector together. There is also one on the other side.
If you pry the plastic up at the clip and pull the two halves apart, it will separate.




Give that a try and see how you make out. That schematic in the e-mail that I sent you should really explain everything.

Bill