: 97 Catera TC + ABS indicators simulteneous

03-17-05, 06:50 AM
1997 Catera..the TC and ABS indicators light up simultaneously at times. They stay lit until the car is turned off completely -- as per drivers manual. Cadillac technicians cannot tell what is causing this. It happens randomly. E.g. some days may go by with no such problem. Other days, sometime after turning the car on, it can happen anytime from moment of ignition, to first time I use brakes, to all by itself while driving. It is unrelated to road conditions, weather, how hard I am braking, etc. It can happen not at all one day, and then every time I drive the next day. Does anyone know about a fix? -Serobin88

03-17-05, 11:00 AM
This is a LONG SHOT, but I had a similar experience with my 93 Corvette with traction control and ABS. I found that I was causing it by pressing on the brake pedal while starting the car. By pushing down slowly on the brake while I cranked and started the car, I was able to mess up the self-test routine. It didn't happen every time, but I was able to duplicate it with better than 90% success. For what it is worth, I owned that car for a few years before this ever showed up. Apparently I simply changed my driving (start up?) habits ever so slightly and started causing this problem myself. Later today, I'm going to try this with my 98 Catera and see if I can cause the same problem.

Hope this helps.

Steve Hogan

03-17-05, 04:04 PM
Does your speedometer cut out as well?

There were some problems with the EBTCM that some people were having (including myself). TC and ABS would come on, as well as the speedometer cutting out. I might attribute your case to maybe a wheel sensor going bad... or its not getting feed from something. No codes are being stored?

03-17-05, 06:57 PM
Steveogan and JeffreyG,

Thanks for your replies.

I never depress the brake pedal when starting the car. So, that is not the cause.

I have no trouble at all with the speedometer cutting out.

Is the EDTCM the same as the ABS/Traction Control module, or Cadillac part #90541367, also called ABS CONTROL MODULE in some online catalogs??

My problem is the two lights coming on and staying on until the car is turned off--and happening seemingly randomly and without any road, weather, braking, driving conditions or other discernable or logical cause.

03-17-05, 07:20 PM
Is the EDTCM the same as the ABS/Traction Control module, or Cadillac part #90541367, also called ABS CONTROL MODULE in some online catalogs??

Yes the EBTCM is the ABS/Traction Control Module. I wouldnt go replacing the module just yet (despite the fact that its also has a heavy price tag) until your dealer finds a dtc code set or finds a way to record it happening- they can setup a system that reads live data while you drive.

03-17-05, 07:30 PM
Thanks Jeffrey,

The local delers charge $100 to look at the car. I was hoping that this forum consensus would be my guide. I know a good mechanic who will get the module and sell to me at cost = $776. He'll use the industry book 2.5 hrs at $80 per hour. So, there is $1000. I fear going to the dealer to pay $100 to hear again, "Gee. It is an American car. We don't know why it does it or how to fix it. See the cashier again." Do you not think that others who have contributed their experiences might not be on to the root cause--this module--as the one and only cause of my car problem?

03-17-05, 08:24 PM
Listen to JerreryG. He knows his stuff. The EBTCM i.e. the "Electronic Braking Traction Control Module" (and the other electronic computer modules) fail a lot less frequently than the repair records might otherwise indicate. They are relatively easy to change out and thus the diagnostic flow charts in the manuals suggest that relatively early. When the actual problem is found, the dealer service techs don't go back and put the old module back in; they just write up the service ticket and you buy an new module that you didn't necessarily need. Get the codes read first (buy a code reader if you need one or get a friendly mechanic to do it for you) and then, with that info in hand, come on back and someone on this site will be able to help you (and probably avoid a $1,000 "training session" for the dealer)

03-18-05, 12:20 AM
What kind or brand of code reader? What would it be called at AutoZone or at Advance Auto Parts? Does it come with instructions?

03-18-05, 10:27 AM
You need a code reader that reads the ABS (brakes) codes in addition to the regular OBD II engine codes. The cheap ones at Autozone do not do that. I don't have a good one to recommend as I personally have had access to the factory Tech II tool when I needed one. However, I have been told that there are some good packages that attach to a laptop PC for $200 that do read these codes. I'll try to get some time later to look these up. Perhaps one of our other forum members can point one out.

03-18-05, 07:54 PM
I went to Advance Auto Parts. A tech used a had-held scanner--plugged it into something near the interior hood release lever--in the foot well area of driver's side. "NO CODES" was the readout. Also, when I started the car--even drove around the block, no TC+ABS lights came in for the first time in 3 days. Anyway, the tech said his kit would cost $350. It did not have Tech II anywhere on it that I could see.

03-18-05, 11:00 PM
Odds are pretty good that he just did an engine scan. FWIW, the Tech II costs about $5,000 - that's why I don't own one - I bought my 98 Catera used for $5,000 :)

I'm waiting for some info on a package of PC software that is supposed to read the transmission and ABS codes in addition to the engine codes. As soon as I get the info I'll post if it looks like good stuff.

In the meantime, I'd go for some of the simple stuff as suggested by JefferyG like crawling under the car and inspecting the wiring harnesses to the wheel sensors. There is a note in the service manual about inspecting them for water leakage, etc. On my aforementioned Corvette, I had a wheel sensor connector get damaged by some road junk and fill up with water and corrode. Threw a fault that was intermittent for months until it finally stayed on steady. That was in the pre-OBD II days, so there were no history codes like we can read today. Once you've done all of the physical inspectung that you can, then maybe it's time to pop the $100 for the tech to read the codes.

03-19-05, 05:25 PM
I appreciate all the comments--have NOT spent my $1,000 yet.
Say...in April 2004, I had a leaky Right Rear axle seal at the differential--exactly where the Wheel Speed Sensor is located, right? The work order said replacement of the seal (the part cost only about $11.00) and "cleaned sensors." I was told that differential oil was leaking and that oil leaked onto the Right sensor. The only sensor there is the wheel speed sensor, right?
QUESTION: Even after the tech tried to clean that sensor, could the oil that leaked onto it have damaged it to where it is causing the TC/ABS indicator lights problem?
I went back to Advance Auto Parts (AAP) this morning--the TC/ABS lights were on and the tech did another code read. No code for ABS or TC at all--just like the Cadillac dealer and the above mentioned independent shop found--zip. I DID find out I need an oxygen sensor. So, the little code-reader that AAP's man used DID see THAT sensor code. Can this mean that the EBTCM might be fine, and that the wheel speed sensor could after all be the cause of all this? The TC/ABS lights problem surfaced 2/2004. The differential leak was fixed 4/2004. I have had the TC/ABS lights problem ever since--never replaced that wheel speed sensor. What does anybody think?

03-19-05, 06:24 PM
Well it is a bit of a coincidence, although a bad sensor SHOULD throw an ABS code. Still it is a relatively cheap test and not too hard to replace. Might be a good idea to inspect the sensor connector first, as that MIGHT be wet or corroded or something. And I suppose it is possible for rear axle lubricant to cause the insulation on the sensor to deteriorate. Worth a shot anyway.

Attached is a PDF of the sensor replacement procedure - it's pretty straightforward. Good luck.

Actually, the PDF is too large to load into this message. Send me an email if you want it --- stevehogan@stevehogan.com

03-19-05, 07:36 PM
SteveHogan, I just emailed you for the PDF. But, from your reply above, you imply that if AAP's small code-reader could pick up on the bad Oxygen sensor, it should have also picked up on the Wheel Speed Sensor as an ABS code?
I do not know the car as you seem to. But, I saw a diagram on GuyHillCadillac.com showing the Wheel Speed sensor as very near the Differential--at the opposite end of the right axle from the wheel, brake assembly, etc.
Would you clarify for me the various functions of this Wheel Speed Sensor? Could such a sensor, located far from the brakes, register an ABS code? If not, then perhaps this is not a good candidate for causing my TC/ABS lights problem. Your opinion?

03-19-05, 08:55 PM
The bad oxygen sensor is an engine code. Engine codes such as this are part of the federal OBD standard and thus virtually all code readers will show that. The ABS stuff is in an entirely different control module which is not part of the federal standard requirements and is somewhat manufacturer-specific. Thus the generic readers don't read those codes. Plus there are some other issues related to safety with using the electronic diagnostics on an ABS system. For example, it is possible to open certain internal valves in the ABS using the right kind of electronic reader. This is done for service reasons, but in the hands of an uninformed user, it is possible to cause the brakes to malfunction - that would be a bad thing :tisk:

I may have misread your earlier post as I thought you mentioned that a Caddy dealer had read the codes. Assuming they were looking for the cause of the ABS & TC lights, they should have caught a code if there was one. Of course, as you point out it is intermittent and I don't know if an intermittent ABS wheel sensor code would be stored. Perhaps another reader has more info.

At any rate, the rear sensors are indeed mounted inboard (it's shown in the PDF I just emailed to you). If you think about it, the axel shaft turns at the same rate as the wheel. Thus mounting them inboard will produce the same signal and (theoretically) protect the sensor somewhat from damage. A bad sensor will indeed light the light (and should set a code).

If it were me, I'd jack up the car - using a GOOD hydraulic jack and jackstands or wheel ramps and wheel chocks - SAFETY FIRST - and slither underneath and do a good inspection job. It's too coincidental that the tech mentioned the sensor as needing cleaning and cleaned it, and this sure sounds like a sensor type of problem. But then, it might just be a coincidence. :banghead:

03-20-05, 10:37 AM

Thank you for comments and for PDF. Yes, in Feb 2004 a Cadillac dealer tech tried to get codes for this TC/ABS issue. No codes at all could be obtained using the Tech II or whatever equivalent they surely have. The service manager told me the tech could not even get the lights to come on as I have described. He advised me to wait until the lights were on constantly at all times while the car was running--that perhaps a code could be read then.

So, I have waited for over a year waiting for the problem to be 100% constant. Yet, the problem is still intermittent. I do wish to resolve it just because I hate owning a car and not maintaining it properly.

Well, I better do what you suggest--what I dislike--get under the car myself to inspect those wires and sensors--both sides in the rear. http://www.cadillacforums.com/forums/images/icons/icon9.gif Maybe an easy resolution will come from this exercise!

03-20-05, 01:10 PM
In all of our focus on the rear sensors, we forgoat to talk about the front sensors. They could be the problem also. I'm emailing you the front sensor procedure right now

10-03-05, 06:47 PM
i'm actually having a similar problem..my tc and abs lights go on simultaneously but my power steering also gets tight or fails to work, the speedometer stays at zero, cruise control doesn't work, and the automatic transmission shifts weirdly at around 5200 rpm. if i hold the gas and it reaches 5200 rpm, it wont shift it. but if i get to around that rpm and let go of the gas for a second, it then shifts. The odd thing about this problem is that once the tc and abs lights go off, all the problems go away and the car acts fine. i'm suspecting a loose cable or computer problem. please help me? this is a frustrating problem.

10-05-05, 03:43 PM
i also forgot to mention that the odometer doesn't work when these problems are occurring as well..also when the tc/abs lights are on (check engine light is on too) , the systems actually dont work too..this isn't really safe..that means i have no traction control or abs when the lights are on..but when the lights go away, every single problem goes away..i don't get it

10-05-05, 11:50 PM
Yes when the lights come back on the EBTCM is alive again or is operating properly. When we had this problem, it would be intermittent just as you describe it.

The steering feeling stiff is because of its setup as a variable assist unit. It draws speed information from the network of sensors the EBTCM uses. When it cannot recieve speed information it goes into some sort of default mode. - No variable assist.

Your speedometer gets this same information.

10-08-05, 11:51 AM
What about speedo OK, all else OK, yet TC+ABS come on and stay on until turning ignition off to clear it--this ALWAYS works? TC+ABS come on while driving, upon starting car, whether braking or not braking, all weather conditons, and all road conditions. It sounds more like a problem for a voodoo exocism specialist than for a mechanic! Yet, could it be caused by one or another Wheel Speed Sensors being bad after 102,000+ miles--manufactured I think by Bosch?

10-08-05, 07:38 PM
What about speedo OK, all else OK, yet TC+ABS come on and stay on until turning ignition off to clear it--this ALWAYS works? TC+ABS come on while driving, upon starting car, whether braking or not braking, all weather conditons, and all road conditions. It sounds more like a problem for a voodoo exocism specialist than for a mechanic! Yet, could it be caused by one or another Wheel Speed Sensors being bad after 102,000+ miles--manufactured I think by Bosch?

There should be diagnostic codes set for that then. If you get the car scanned (for free like at an Autozone) then you'll know whats going on.

Its certainly enough mileage for this to occur even though it can happen at any time. Might be a communication error between the wheel speed sensors or other. Does sport mode perform properly?

It is indeed a Bosch traction control and ABS system. The phsyical brake setup is by Lucas.

10-09-05, 09:54 AM
Thanks very much JeffreyG,

Sport Mode works great. TC+ABS do not come on every drive, every day. This is a sporadic, "self-willed" problem that has "schedule of its own." All else in vehicle works fine as far as I can tell.

The TC+ABS problem appeared Feb 2004. Even a Cadillac dealer scan was not able to detect anything wrong. Having a problem that even a dealer cannot diagnose is very dissappointing. Three Autozone scans also resulted in no problem showing.

One member of this forum advised me that Cadillac Catera ABS systems ought to be scanned ONLY by a dealer. He told me that only Cadillac can get into the ABS codes correctly. He said that accessing the codes can change them and screw the system up even worse in the hands of the "not properly trained." IS THIS TRUE? I spent $100 for the dealer's scan. Cadillac has my money but does not have a clue what is causing my TC+ABS sporadic indicator lights problem.

The Catera driver's manual clearly states that these two lights may occasionally come on together. The manual states that turning the car off, then on again will clear the condition. This is certainly true. Yet, mysteriously, not even a dealer knows what causes this problem to be so frequent--almost every day, almost every drive, yet not always. It is a ghost.

Since I do not have any speedo problem, I think that my main TC/ABS module is probably fine. I did replace one wheel speed sensor. This did not solve the problem. I may decide to replace the other three. Money is money, though, and spending for "let's just see" is not a good habit.

I welcome any other suggestions.

10-26-05, 04:32 PM
I had this problem with my 2000 Catera. My friend at the local salvage yard let me try the transmission module located under the dash but it did not fix the problem. Then he let me try the TC/ABS module which took us 3.5 hours to replace and it fixed all the problems with the speedometer and check engine-TC-ABS lights. He sold me the part for $150.

10-28-05, 08:09 AM
There seems to be variations to this family of problems. 1> TC+ABS come on simultaneously only if and when the car wills it, but with no other problems. 2> Steering problems accompany "1". 3> Odo- or speedo- problems accompany "1". The last 2 scenarios seem to be solved with a replacement of the EBTCM module, which seems to be the same thing as the TC/ABS module.

If anyone else has had scenario "1" above--no speedo, steering or odometer problems, just the TC+ABS coming on sometimes but not always as the car seems to randomly will it--please also make an entry. Thanks!

11-01-05, 09:34 PM
Consumer Guide http://auto.consumerguide.com/ remarks under service notes
for the 97. "Wiring problem causes TC/ABS to come on intermediately". No other clues. I have the same problem mentioned with them disappearing once the warmed up car is shut off and then restarted. With 150-200 inches of rain a year, I am not surprised that the comments regarding the sensors are being affected by the moisture. Will keep checking this post for solutions.
A Johnson- Ketchikan, Alaska