Hello again and sorry for my pause. Maybe I didn't write anything last time But I read there tech forum almost every day. And my broken EBCM is there reason. I've got a 99 vette with suffice rarely active handling not only traction and ABS. I did all from tutorial about abs /traction issues. And somebody did it before me not long ago. Everything is clean and ground is doubled. Zero result. Last and expensive step from instruction is rebuild or replace module. Ok. I found a shop here in Russia which sells parts for USA domestic market cars only. Good guys. Pick-up fans. They prevented me that it would be not cheap. About 1000 dollars. But answer from USA was that Delco model 09356971 is out of stock and never be again. That is queer I didn't think. For example you can build any 20 y.o. Toyota anew of new parts. Any of it would be at stock. Ok, I wrote a e-mail to American official dealer and answer was that honestly last module was sold more that four years ago. How?! Last chance was ABS fixer. And today's answer shocked me. This module is seldom not reliable and couldn't be fixed.
It is very hard to drive car here without such systems.

Maybe someone tried to install another one module? From 2001 year or another car. Perfectly that Vette's computer understand it. But for example, I could drive my car comfortable without active handling. Even traction. I want it but not necessary. But without ABS realy hard. And that lamps on dashboard! Only ABS and computer deception about traction and active handling. Thats enough. But better when all works perfectly.

PS tried to find used module but... the price is from 1000 to 3500(!!!) dollars! For what? For unwarantied junk which could brake in next 100 miles? Or some people sell broken module for 300-400 dollars. If ABS fixers cannot fix it what are sellers waiting for?

PPS I read a myth here on forum that someone could fix this module. But price is about 800 dollars. Thats a lot. But it is last chance. Maybe someone could give me contacts?

 

The 97 - 2000 NEW EBTCM are no longer manufactured or stocked by GM.


Your best option will be to find a good used module. The C1255 error is a FAILED PRCCESSOR inside the module and can not be repaired. If you have proper POWER and proper GROUNDs, it can only be an internal issue.

Try this!
Measure EACH EBTCM fuse to chassis ground. There are TEST POINTS on top of each fuse. Measure each test point to ground and make sure that you get full battery voltage on each fuse.
There are THREE EBTCM FUSES. One of them will have voltage when the IGNITON SWITCH IS ON. The other is a function of the brake peddle position.



The ignition powered fuse is the fuse that I am concerned with. If it is less than battery voltage, that could cause module issues.


Open the module and make sure that all the internal femal pins inside the module and in the MAIN CONNECTOR are not damaged and are clean and dry. The femal pins can and will spread apart and make poor contact with the male pins. The female pins can be repaired to make better contact.

Mini Fuse 5 is ignition Switch powered




Im giving you all the helpful tips that I can think of short of getting a used working module.

Hope this helps.

Bill

 

Thank you Bill.
Hope this helps too.

Here in Russia lots of Volvo cars has got the same troubles. And only way to fix it is soldering new CPU. New processor is not cheap (about 100 dollars). Reballing costs about 200 dollars. But such repaired module is 100 times better than used one without any warranties.

PS I've got errors only when engine is hot. Sometimes error lights on dashboard disappear and anything works well. Symptoms of broken processor or not?

 

It could be done if you're quite capable of that sort of thing. The sensors and wiring is already there for the newer ABS system. It requires mounting the complete ABS pump setup and plumbing it and then changing the wiring connector. The 2 parts I'm uncertain about are the SWPS working with the newer system (schematics show the A and B signals the same but are they really the same?) and if the BCM will communicate with the newer system. I suspect an active handling BCM will be OK and this would only be an issue on a car without active handling.

 

The hard part is FINDING the processor, many modules have NO NUMBERS on the internal parts to be able to source them back and many are ASIC's so are only available from limited sources (if at all). Then it's probably surface mounted which takes a bit of skill and a very small tipped soldering iron to install.

 

Good luck when it's a IC die wire bonded and potted directly onto the circuit board and it's also a programmed device with no program available for the new part.

 

I measured them all. Big fuses are OK. And when ignition is on battery voltage is 11.68 but fuse is 11.45. Think it couldn't be the trouble. Or not? Bill, help me please.


Maybe if all other methods of repairing this module would be vain I'll try to change whole module. Price is from 500 dollars for working EBCM+pump... and asking a connector cut.

If someone installed different module to the car tell me please. Vodka from me

Maybe I don't understand something but 3500 dollars and even 1000 dollars for module which only god can know about time of its death is a highway robbery.

I understand this. But maybe someone made some experiments with it and by cut and try method and solved the riddle. Maybe this person has got unique knowledge. Ok! Me and a lot of C5 owners with the same trouble ready to give him a pretty penny.

 

This problem has been around for some time with the pre 2001 cars. Those cars are past the 10 year parts stocking that manufacturers are supposed to keep parts AND I think Bosch designed the unit AND GM went through that "quicky" bankruptcy which allows them to get out of many issues like this. The aftermarket is having a hard time filling this void because there are little/no schematics and/or parts to repair them.

This is why I try to steer people away from the pre 01 cars, at some point (very soon) there will be NO way to fix this since all the used modules will get gobbled up and nobody is repairing them because of lack of parts.

Trying to use a newer module has it's own issues, some of the early cars had the EBCM in the REAR of the car, it was move to the front but if yours is one of these, all you brak lines will be WRONG not no mention you ECU may not know how to talk to this later model EBCM.

You best course of action is to try to find a working used one and PAY, take your old one apart and see what you can do.

 

Vette is very popular in USA. But I'm living at a different country. I wanted c5 with manual transmition and there were only 2 such cars for sale. The second one was 2002 z06 But 40 percent expensive and at another town far away.
Sad But true. Maybe Porsche or something Japanese like Supra or Subaru WRX STi is better choice in Russia but I dreamed about corvette.

Maybe I am a fool but want to find someone Who already installed different module. And if he tells that such method is failure to I'll buy used EBCM module and sell the car on next spring. If nobody tried to swap module. It is winter time soon and I will have lot of time.

 

Only the '97 and early '98 had the system in the rear. That is obviously not an issue with your '99.

The EBTC module sends a PWM signal to the PCM to cut the power. People have swapped the PCM between all years of the C5 without any ABS system issues so don't even give that a second though.

No-one here is posting that they have done it. The '00 and earlier cars can be had in the $10k range and a shop would likely charge around $3k to do the swap so no-one will pay a shop to fix it. Then, there aren't many people who would attempt this at home since electronics scare everyone.

Here's my overview of what I found looking at the wiring diagrams.

http://forums.corvetteforum.com/c5-t...ibilities.html

Overall, I don't see this as being overly difficult, but then I like challenges. If mine needed fixing I'd be doing the swap. As it is, mine works and I have another module in the garage.

Worst case, you need a column too so you can mount the newer SWPS and you need to upgrade the BCM. I can't tell you if the newer SWPS will fit in your '99 but it might.

 

I will try to answer some questions here and try to resolve some stuff that are not,, well lets say factual

1. I agree with lionelhutz. The actual MICROPROCESSSOR is NOT repairable. Its not a solder on processor. Its burried in a gell and attached to the to secondary board with micro wires. You are not going to find the processor on the market let alone flash in a C5 EBTCM logic program.

2 The Brake line routing from an early FRONT or REAR Mounted BPMV module will NO WAY match up to a Late Modle BPMV

Im not saying that it CANT be done,,, but,,, you would have to be really skilled at completely rerouting and plumbing the brake lines.


I dont have pictures of the early FRONT mounted BPMV and EBTCM but I do have the 97 and early 98 rear mounted stuff. Some time mid production in 98, they moved the module to the front of the car.

Here are all the early and late EBTCM and BPMV pictures that I have:

EARLY Stuff (97 Coupe)
















See 2001+ EBTCM/BPMV NEXT PAGE

 

2001+ EBTCM/BPMV




























Then, you would have to rewire the newer module to the older system and add the Active Handling components if you wanted AH.

You would have to find a compatible SWPS that would work with your column and system..

 

Is it possible to run the car without EBTCM when it goes bad??? I just might sell my C5 knowing there are less and less parts out there. WTF

 

His car has the AH components and it has the BCM which should know about and control the competitive mode.

The 01-04 SWPS will work if the A & B signals from the 99 unit don't work. So, he doesn't need to try and find one. The question to ask is if the 01-04 SWPS can be installed on the '99 column or if he would require a 01-04 column. He'd also need the connector for the newer SWPS if he has to swap them.

Don't forget, the '99 also has the SWPS that can't be replaced so sticking a $1000 used EBCM into it and then having the SWPS fail would really **** you off.

 

YES!!! ABSOLUTY!!! When the system fails it defaults to a fail safe MANUAL Operation and you have brakes like any other car without ABS. Depending on what actually fails, you may retain the ABS and not have Active Handling.

It is like you turned the system OFF,,, but you get messages telling you of the failure.

Someday,, Someone will have a solution for our issue.

BC

 

Good news!
Of course it would be terrible if SWPS systems are incompatible. But we cannot know that before we try. But at worst case I could go farther. Swap other electronic modules. Or just resell all parts which I already bought for the same price.

I understand that. There are lots of special processors in the world and belive that every ROM could be readed and re-flashed. But I'm not an radio ham or electronics and chips geek and don't have such people at my surround.

And the second. I've got erros only on hot engine. Now it is autumn here and air temperature is about 0-2 Celsius degrees . I could drive it at quiet pace for a half-hour or more. And everything working well. ABS when braking at slip road traction when rev up and active handling on steep turns. But if engine became 70 Celsius degrees ore more error comes. I understand that brake liquid became very hot when driving is active. But first, maybe that means that some contact peeling off. May be at the board or somewhere else but probably issue is fixable. And the second maybe provide extra cooling to this module. Radiators and fans. Even if it will be for sale and forget about Vette as a terrifying story. But..... I like it and don't wanna sell.

I didn't remember but.... my EBCM looking like from pictures of 97 Vette and BPMW subjective loks like 2001's. I'll check it again in the evening. But pipes aren't a big trouble I think. Reinforced hoses would help.

Right now i don't know where I can buy such module for $1000. Here in sale\buy forum is nothing. On eBay there are only two offers. First from unknown car for 2000$+shipping to Russia. Second from 50k miles car (if it true) for 2500$+shipping. Here in russia you can buy a whoe 911 Porsche engine for this price. Troubles at my car began on 70K miles. Buy a module for quarter of US car price which have only 20 000 miles reserve is a poor choice. Only for sale. But I have great plans on this car. And already ordered some tuning parts.

Know that here in Russia very we have got not so big earnings (in villages $300-700 dollars workers 700-1500$ engineer or manager and in cities $700-1500 for workers and 1200-2500$ white shirts) and expensive cars. New Ford Focus is about $30000 Right now there are three C4 for sale. Price is above 20 000 $. C5 starts from 30 000$ and manual transmission is very rare. C6 $40000 and more. Remind that there were only two cars with M/T for sale. And in 2008 here was consummation of blocking customs taxes in Russia. Cost of only customs tax for 5.7 car is about $35000(!!!!) without price of the car. And that's the motive fix my car well but not just for sale.

PS sometimes i think that Porsche 911 is better variant for Russia. But I hate this beatle-looking bucket. I don't like exterior, sound of engine. Here in Russia Porsche 911 is a car of young lovers of money bags. Sons and daughters of millionaires.... but lots of parts and services. Lots of junkyards. But the first reason that I just don't like Porsche. Not my car.

You can read my greeting topic at this forum. This car was my childhood dream which comes true and I want it's perfectly working.
I have got a lot of plans on it included supercharger, full respray and rebuilding interior. Broke my dream by C1255 error - never!

PPS sometimes I think that C6 is better choice. Its much more fresh, many used and new parts in Europe. It is more popular. Sometimes you can see it at streets of Moscow. But in my humble opinion C5 exterior is much more beautiful. Blind headlights.... oh, racing car from some old movie

 

Thank you

 

Hey, if you love the car and can do the work then go for it. Don't let a missing piece get you down. At the end of the day, the chassis of every C5 is the same so the newer parts will work. You just have to be determined enough to make them work. Let me know if you have any questions if you attempt the swap.

 

Good and BAD idea, it's easy to cause a short while EXPERIMENTING and causing even worse damage. Unless you have a good current schematic of EVERYTHING, this is a dangerous way to try to fix something this complicated. He's also in Russia, with little or no local support and could make the car unusable tinkering. Driving it the way it is is tha safest thing and trying to find a reasonable used module (if that's possible).

 

LOL, see it's all subjective based on who you are. There is no random experimenting, putting odd power to different wires. You use the wiring diagrams and you hook it up same as same. Then, you determine if parts don't talk to each other (like BCM to EBCM module).

No way would I pay $2000+ for a used module when I could buy the parts to upgrade to the new generation of system. For $3000 you could likely get the wiring plug and newer ABS system and bracket and BCM and IPC and column and another part you'd need to convert it to a system that can be fixed again later.