Elec Brake and Traction Control Module

[charliemax]

The other day my ABS and TC lights came on the '98 SSEi. So I checked and put dialectic on the front wheel sensors. The light was out on next start-up. But after I rolled, it came back on.

So, I took it to the dealer to get it read on the Tech II. They said I need the EBTCM replaced, and I had a history record on the front wheel sensor.

My current, and quite capable, fix is black tape over the lights. But I'm pretty sure i can source the EBTCM at the boneyard. The module looks like it is a receiving unit bolted on the back of the monster octopus valve under the airbox.

Q #1 - Assuming i get the matching Model# with TC, and it's off of a 96-99,... is there anymore to it than just crossing my fingers and swapping it in? Then clear the codes by just detaching the battery

Q #2 - Dealers hate me, because the only time I go to them is when I need a diagnostic from the Tech II, on an enhanced code situation or ABS, which I can't pick up with my scantool. Can anybody handicap the odds, that I just have a WSS problem? It's really odd that the light went off and held, until the ABS did the roll test. And i have had zero problem with the ABS working before the light, the light originally came on while I was driving (not braking) on a dry, clear road. Trying to pitch the $900 repair first, then replacing the wheelhub/sensor afterwards, would be a familiar way for them to do business. And no, they wouldn't tell me exactly what the codes were.

Thanks for any help.

charlie

[LeSabre in Buffalo]

Try the hub first. That cleared up a similar problem for someone else recently.

Swapping the ABS module isn't terribly hard with line wrenches for the brake lines and removing the bolts on the top and front of the unit. It does have to come out from 6 brake lines, where a second person to hold brake lines out of the way is handy.

[charliemax]

Try the hub first. That cleared up a similar problem for someone else recently.

Swapping the ABS module isn't terribly hard with line wrenches for the brake lines and removing the bolts on the top and front of the unit. It does have to come out from 6 brake lines, where a second person to hold brake lines out of the way is handy.

hub - I'm heavily considering that. The ABS system had engaged and disengaged fine just a few days earlier in a light snow.

ABS- That's what I'm trying to confirm, it looks like I don't have to remove anything on the the BPMV. All of the lines and funky stuff are on the front. The EBTCM looks like it bolts on the back. Is the EBTCM more than just an electronic unit? i. e. it has a mechanical function?

[1fatcat]

I would like to see a snap shot of the wheel speed sensors when this problem is happening. If you replace things, the electronics and hydrolics of the ABS pump assembly do seperate.

[charliemax]

I would like to see a snap shot of the wheel speed sensors when this problem is happening. If you replace things, the electronics and hydrolics of the ABS pump assembly do seperate.

I'm not sure I understand what you are saying, the situation was an event, not measurable as an ongoing occurrence at this point. Once the ABS/TC light came on, the ABS system is out of the operating loop. All the Tech II can do is read the error messages. I'm not aware of any portable tool which can data stream the WSS signals from the ABS subsystem while the car is on the road.

I would assume the WSS is like any similar sensor, it transmits a frequency of modulating or on/off states by which a speed can be calculated. One way to check a WSS without guessing, would be to connect a multimeter with an AC (not DC) 12 volt input on one connector lead, and then read the values as you handturn the wheel. if you get no oscillation from low to high, then the sensor is dead.

When you say they can "seperate", I'm assuming you were referring to what concerned me. Similar to a "Case Learn", it would seem that some procedure would have to be run when you just swap in another control module or the signals and the hydraulics might be out of synch.

Again, I'm sorry. I don't think I'm understanding your question.

[1fatcat]

I would like to see a snap shot of the wheel speed sensors when this problem is happening. If you replace things, the electronics and hydrolics of the ABS pump assembly do seperate.

I'm not aware of any portable tool which can data stream the WSS signals from the ABS subsystem while the car is on the road.

The Tech2 can.

[charliemax]

I would like to see a snap shot of the wheel speed sensors when this problem is happening. If you replace things, the electronics and hydrolics of the ABS pump assembly do seperate.

I'm not aware of any portable tool which can data stream the WSS signals from the ABS subsystem while the car is on the road.

The Tech2 can.

Well, I was talking about something a DIY could afford. Besides the fact i irked them to the point that they wouldn't give me the actual codes (that's my problem), tomorrow morning I can ask the mechanic to ride with me and read the streaming data. That seems to be the easiest way to tell if a WSS is actually bad or was just an isolated event. That history record could have been (i think) 50 ignitions ago.Thanks.

edit: I did buy try the Actron ABS scantool. "Reads most cars from 1996and after". Well, it actually only reads 3 GM cars before '99... and only 1 or 2 years. But it will work for Bonnevilles 2000+. Only $99 last week at Rice Central. One problem and it pays for itself. FWIW.

[1fatcat]

Irking them is unavoidable when you go in there asking for free advice. Remember, those guys are worth $100+/hr to the dealership. The dealer generally does not allow you to converse with the techs unless your on the schedule.

And sneaking in the back to talk to a tech who your friends with, generally gets your friend in trouble after you leave.

[charliemax]

Irking them is unavoidable when you go in there asking for free advice. Remember, those guys are worth $100+/hr to the dealership. The dealer generally does not allow you to converse with the techs unless your on the schedule.

And sneaking in the back to talk to a tech who your friends with, generally gets your friend in trouble after you leave.

fatcat....

With greatest respect and appreciation for your the help you have provided, we're obviously not communicating. At what point did i say this didn't cost me $79 for a 15 minute diagnosis. And at what point did i say that it wasn't going to cost me $125/hr for the time I would spend with the mechanic today? And I had/have an appointment for each occasion.

Their disregard for me comes from the fact that I am an active consumer and do the work on my own cars. I believe that is, or maybe I'm mistaken and it used to be, the attitude and purpose of the old Pontiac Bonneville Club. What pinches my nose is the shortsighted, and failed business practices of GM and their dealerships. And their stubborn arrogance to continue them.

As an investor, I have opportunity and occasion to read trade magazines on the financials of dealers. Currently, Wall Street analysts have average GM dealership revenues down 65%. The only reason they are not worse, and not deservedly bankrupt, was the infusion of $3 billion dollars directly to the dealers. A subsidy. Free money. Actually national deficit, to be paid to by the taxpayer and Fed balance sheet schemes.

If I can go on record, I was a strong advocate for greater subsidy to the car industry when we have committed $12 trillion to the Wall Street Banksters, which doesn't include our full responsibility and guarantee for $204 trillion, total notional value of risky derivatives held by the top 6 Banksters.

So, in return, my experience tells me that rather than learn from their failed business practices, the ex-Pontiac dealer in Limerick, PA (which I paid for) diagnosed a P0171 DTC as a bad fuel pump which they would be happy to replace for $750. Which I fixed by replacing the FPR. The failed UIM/LIM which Saturn of the Valley in Quakertown, PA refused to believe (twice) and fix under the GM certified service contract (until I took the car to another dealer which documented the failure), and Kelly Chevrolet in Phoenixville, PA who refused to give me the DTC codes which supported their conclusion that I needed a $950 replacement of the EBTCM. The codes which I had paid for.

In all cases, each dealer's practices did not take into consideration the sound business practice of treating the customer fairly and honestly. It is easy to see why they would generate no brand loyalty, nor future business from this customer.

On a personal note, I have 2 1/2 college tuitions and a wife who fought cancer 3 years ago with the usual coverage cap bills. My income would indicate, at my advanced years, I should be enjoying some type of fancy car for everybody to oh and ah about, but I am intensely proud to both preserve the capital and get the good feeling of self-reliance by owning 3 Bonnevilles. To me, my Bonnevilles stand for my commitment to spend my dollars in my country, and are a eulogy to what was, and what can be a foreshadowing of greatness in the future.

If there is some prejudice of cheapness and "sneaking" towards people who have low post numbers (which would also be counter to the welcome I found at Pontiac Bonneville Club 4 years ago) that is because of the 500+ posts which were not grandfathered to whatever schism occurred in Pontiac Bonneville Club. When I took my time to repay the kindness afforded me by friends and strangers of the community, by helping solve others problems, actively participate in Pay-it-forward initiatives, and visit in a few Meets.

I apologize for going on like this, but you may have mistaken this Marine for someone else who sneaks around. I stopped "sneaking" and expecting something for nothing 55 yrs ago when I was 5.

I am amazed at such an unfounded derision would be found at Pontiac Bonneville Club.

Regretfully,

charlie

[willwren]

Semper Fi, Jarhead.

Getting back on topic, the WSS was a HISTORY code, so the hub may not be an issue. That could have been caused by ice, gravel, salt, dirt, etc. The EBCTM is a fairly easy fix, old friend (to prove how old, I'll update your post count to be what it's supposed to be as soon as I find my danged spreadsheet), but wrecker prices may vary GREATLY.

Perhaps the best thing to do would be to simply patch it in at the wrecker to see if it solves the problem, changes the problem, or makes the car blow up. That's alot easier than a hub for starters, and might rule something out.

[1fatcat]

Ok, that went well. I'm sorry if I offended you, that was NOT my intent. You said you irked them, I assumed it was due to you wanting free advice. Thats what your here for, right?
If you are willing to do the work, then you could try diagnosing the problem yourself. You can measure the millivolt output of each wheel speed sensor with a digital multi meter. The sensors should measure compareable to each other. Some difference from front to rear could be expected. While manually spinning the wheel smoothly 1 revolution per second, the sensor should generate about 300 milivolts or more. If one is low, it will not feed the correct speed signal to the EBCM and will cause problems. Checking all the power and ground feeds at the EBCM is a step you should take too. You will need an FSM, a jack and four stands, general tools, a DVOM and some jumper wires with back probe pins to do these tests.
Let us know what you find.

[charliemax]

Semper Fi, Jarhead.

Getting back on topic, the WSS was a HISTORY code, so the hub may not be an issue. That could have been caused by ice, gravel, salt, dirt, etc. The EBCTM is a fairly easy fix, old friend (to prove how old, I'll update your post count to be what it's supposed to be as soon as I find my danged spreadsheet), but wrecker prices may vary GREATLY.

Perhaps the best thing to do would be to simply patch it in at the wrecker to see if it solves the problem, changes the problem, or makes the car blow up. That's alot easier than a hub for starters, and might rule something out.

wilwren...

It is just great to see that famous Pontiac Bonneville Club callname taking a minute to drop in on an old FMF First Shirt.... got a half hour of good guidance this morning and then headed this afternoon for the JY. The circuits/connector tested clear to the EBTCM, so I didn't have to trace any wires. Took longer to locate the right model, than to pull it. Darkness beat me out of the yard, so I'm going to slap it on "ready, fire, aim" on Saturday.

If it nukes the ABS octopus valve, what's the downside? My ABS doesn't work? We're already there, so I'm holding the line.

Never saw the point to ABS, which common sense driving hadn't already solved. ABS just keeps ya straight, and gives you a little steering, so you can choose what ya crash into.

Glad to see you doing some stewarding of Pontiac Bonneville Club. Hard luck looks to pressing down on many of our folk, and they are going to be keeping their cars longer. They will be looking for a strong hand for help, from time to time. If we aren't the ones to hold out that hand, who's going to do it.

Semper Fi, Brother,

Charlie

[charliemax]

For future reference..

The EBCM/EBTCM is a simple bolt-on swap in the '96-'99. The unit is pure electronics, so there are no installation complications with the valve system itself. You'll need a Torx bit for the 4 casing screws. You just have to make sure you match the model of the unit, which indicates whether it has "TCS" or not. They have a durable label on them which clearly provides that info. Just lift up your airbox, and you'll see it.

The part itself is another issue. GM has placed it on their "national control" list. So there is an inventory/supply issue. Even at GMpartsdirect it's $355 (dealer is $700), and it may be a lengthy backorder situation for them or a dealer. Pricing them pre-tested at a salvage yard had them in the $150-200 range.

I went the U-pull-it way and it was $18. I'm not a big fan of electronic yard parts, but in this case, it seemed the right answer. The EBCM/EBTCM is a nice tight cede to the monster valve unit. Likely it will clearly work or not. So you don't have to suffer the in-between world of works-but-faulty, which just further confuses the solution. For an hour and $18, I wouldn't have minded doing a couple before I got a winner, considering the cost of the other alternatives.

Another note, the ('98) FSM would lead you to believe that you won't be able to clear the ABS problem lights/codes without a trip to a Tech II (or 50 ignition-and-drive cycles, which is too long to get feedback for me). But mine cleared immediately after the swap, which included disconnecting the battery for the swap.

So if you're doing the black tape over the dash-lights thing (like I did) for an EBCM/EBTCM problem, you might like to know there is a budget solution. In my state, your friendly mechanic will likely let it slide, but if you have ABS, it is supposed to be functioning to pass inspection.