Error lights: ABS INOP and BRAKE come on randomly?

[watson023]

I've had this problem on and off for the last, I guess, month. My ABS INOP and BRAKE lights come on randomly. Most of the time when I turn of the engine and restart the car, they go off, but sometimes, they come back on when I start it back up. I'd rather not spend a whole bunch at the dealership if anyone has had this problem before or has any ideas. Thanks.

[mrr23]

if the code is stored, maybe run by an autozone and see if they can pull it.

[98Camarod]

Did you recently put on tires? I just put on new tires and the rear are taller than the front, thats why my lights are on. I wanna get this fixed, it is ugly having the lights on while youre driving.

P.S. mrr23 these wheels look awesome, i'll post some pics probably tomorrow.

[tdking112]

if the abs inop light is on while your driving you will not have functioning abs. if you slam the brakes in this situation your wheels may lock. it can be any number of things, from a wheel speed sensor to the (ebcm)electronic brake control module(expensive). since it is only intermittant i would guess that the is electrically open or shorted internally. theres no way to know what it is exactly unless you scan for a trouble code.

[astyles]

when this happened to me it was a grounding wire to the radiator support on the drivers side

[KageSS]

I've had this problem on and off for the last, I guess, month. My ABS INOP and BRAKE lights come on randomly. Most of the time when I turn of the engine and restart the car, they go off, but sometimes, they come back on when I start it back up. I'd rather not spend a whole bunch at the dealership if anyone has had this problem before or has any ideas. Thanks.

Check for loose wires, batt, ground, etc.

[ninobrn99]

autozone wont be able to scan it. you need a bcm scanner. if you know someone with hpt or efi, they should be able to tell you what code it is. have you done any work to the rearend at all? I know when i changed my rear out for the 9", my light came and stayed on to this day :mad:

[ProwlerZ]

Here's the low down: If the light is on, then your ABS is being turned off, generally not a problem, as long as you know how to stop your car without ABS, which almost everyone except soccer moms and other stereotypical drivers knows. The problem is when your light isn't on. If you recently change tires, then the braking proportion has changed, along with the weight gradient, and your rear brakes will lock before your front brakes. It will feel like you're using a big metal sponge to brake with... Many people ignore the lights, and don't worry about them, but since you have to be driving for a short while before the system recognizes the error, that initial time frame can lead to an accident, as it has with many (just search the forums). You either need to balance out the tire sizes front/back, or buy an ABS delete kit, then physically turn off the bulbs (since they'll always be on). Please, don't ignore this, it'll catch up with you.

[watson023]

autozone wont be able to scan it. you need a bcm scanner. if you know someone with hpt or efi, they should be able to tell you what code it is. have you done any work to the rearend at all? I know when i changed my rear out for the 9", my light came and stayed on to this day :mad:

I got hit in the rear end about a year or 2 ago ($10,000 in damage), but nothin other than that. I'm gonna get the dealership to check it out when I get it serviced next (soon).

[15T01Z28]

i had the very same problem. as you i checked all the wires. i found nothing. it wasnt until i was replacing the batter that i found the problem. one of the connectors where over tq'ed. i started to lossen the bolt and the whole barrel nut poped out. ever since the batter replacement its been fine.

[watson023]

I took it to the dealer and was told that I just need a new brake control module or somethin. A couple grand...I can go without anti-lock brakes for a while.

[98Camarod]

My lights still come on after I go over 55mph with my new wheels and tires. My car still stops fine.

[andrew69_04]

buy the abs module off ebay. you can pick them up cheap.

[NVE THIS]

You didn't have any work done to the rear did you? I had a similar problem when I destroyed my stock rear at the track and installed a Strange 12-bolt. Do you have Traction Control on your car?

After installing the new rear and finding that ABS/TC didn't work, I spent many hours and email to/from Strange to diagnose and fix the problem. What it ended up being is a design difference in the Strange/GM rear's. There's a Traction Conrtol Module that goes in the backing plate of the rear on each side. I found out by trial/eror that the sensor was sticking in too far in the backing plate, thus messing up the readings from the reluctor (sp?) wheel. I ended up installing 2 rubber o-rings as spacers between the backing plate and the TC Module. Fixed my problem, now I need to have a metal spacer made as the rubber o-rings are giving out and the sensor is at the smallest angle.

This may not have anyting to do with your problem, but something to check out.

-Bryan

P.S. I can include a pic of the sensor if you want.

[oneBADDz]

Have you changed tires or installed a stall converter recently?

[watson023]

Have you changed tires or installed a stall converter recently?

Naw, it just started actin up on me one day. Just one of those things on a GM that breaks after a couple years I guess.

[sic2001]

did you ever find out what this was? Mine is doing the same thing now, any help would be great!

[watson023]

did you ever find out what this was? Mine is doing the same thing now, any help would be great!

Yeah, it was actually my electronic brake control module (EBCM) which the dealership said would cost $1,000 plus, installed. I got a buddy at another dealership who can get it for me and install it for a total of $550 which is great!

Yours could be something else though, so if you can (without paying too much) you should run diagnostics on it to see exactly what it is. Could probably even be a wire (much cheaper than $500 or $1,000 I'm sure).
Good luck. Hopefully it won't be as expensive for you.

[sic2001]

codes that came up were C0550 ecu malfunction,C0896 device voltage range and U1301 communication. Any help from you or your buddy would be great!

[sic2001]

k, for those who follow and have the same problem, mine turned out to be the wire between the two fog lamps had corroded and the connectionneeded to be redone. Its the wire that runs in front of the radiator.

[oneBADDz]

Another one: mine is because I have slicks and skinnies on and the rears are taller than the fronts. Without the same size tires front and rear, ABS cannot function properly because it doesn't really know when you're slipping based on wheels speed and you will get the brake light and ABS inop

[GTOSCOTT]

when this happened to me it was a grounding wire to the radiator support on the drivers side

I have a 97 formula firebird convertable, this recently happened to me too, abs inop light on constantly, and flashing lotrac and brake light intermittenly. I had recently replaced my brakes, and installed a SLP manual fan switch, so I had lots of possibilities. It ended being the ground stud by the passenger side shock tower that was loose, just tightened it with a 13mm socket, reconnected the battery and it was done! Whew! thanks for all the info, saved me a bunch of dough!!!

[sic2001]

well, I was wrong, it was the EBCM. It went so long in between going on I thought I had fixed it. I bought a used "electronic brake control module" off Ebay for 35.00 and WHAM problem solved. Just make sure you get the correct one, they come with traction control and without. They are hundreds of dollars from the dealership so I suggest shopping around if this happens to you.