Hey Everyone, Recently purchased a 2000 Chevy Blazer Ls, its got odd problem....when you drive on occasions...the ABS AND BRAKE light stay on sometimes it never comes on..I had a Diagnostic done to it prior to purchasing it and computer shot out no porblems...but its preety weird, guy I bought it from said it happend for first time when he got the car fully detailed and they think when they were cleaning wheels and rims maybe a sensor got damaged etc??? car drives real good...I took it from LA TO VEGAS 260 miles and it never turned on ( abs % park brake ) but if i drive it 20 miles, stop to pump gas and turn on to go it turns on again....car has very low miles at 57k and runs very smooth...no issues...but anyone got any inputs on this weird case....???

 

I would take a very close look in behind the front wheels at the wiring to the abs sensors. You may have a poor connection which is causing an intermittent malfunction.

 

I bought a 2001 a week ago, mine did this very thing on the way home from the dealership! lol I have seen it before and it was always a sensor or mismatched tire sizes. I am guessing sensor on mine as well.

 

I have this same problem on my 96 I just picked up tonight. the first time you start it cold, it seems to display the ABS/Brake lights. If I turn it off and restart, the problem goes away. Oh, one other thing, when the ABS/Brake light is on, the radio, ac/heater, and horn do not work. Once I restart it, the lights go out and things work ok...any clues? I think the guy before me had the turn signal/wiper stalk replaced, so might have been when that was done.

 

Hey! to everyone.. I got a very simular problem witha 2001 Zr2 I just purchased. I have read every post regarding ABS and many say or explain the very same thing, Sensors.... Sensors..... Sensors. I just want to throw out my exact concern with the ABS problem and ask a couple of questions before I fall prey to an excessive repair bill. I am not a dumb person and actualy have expierience with computer technology, but not automotive technology. I am realy hopeing to get some qualified responses from perhaps a Goodwrench Tech or Manager. OK' Here it goes...

The problem: Sometimes (maybe 50%) when I start up my Zr2,imeadiately after the bulb check mode the yellow ABS will come back on then one second later the red BRAKE light will come on. Both will stay on until I turn the ignition off. Brakes work perfect, no low speed anti-loc activation, no problems at all except the two lights. The other 50% of the time; the ABS and BRAKE lights will stay OFF after the bulb check and never come back on until maybe the next time I shut the engine off and restart. Neither the ABS or the BRAKE lights have ever come on while driving or after the engine started and they remained off after the bulb check. By the way... No Codes stored or present with the lights on or off.

Everyones soultion so far has been to replace the speed sensors (wheel bearings), this would be a very expensive way for me toproceed since I would have to take it to a garage for the repairs, and I don't think they would accept me bring my own parts. Kinda like going out to a resteraunt and bring your own stake. I can not understand the fixation of blaming the sensors for such an erratic problem.

Perhaps someone could assist me in understanding the following:
1) Without moving the vehicle, or even turning or touching the steering wheel, I get the lights one time I start it, shut it off then get NO lights the next time I start it up again. Sometimes I can start the engine and shut it off many times (not moving the vehicle, just sitting in the same place in the driveway) without the lights coming ON. Other times the lights are on everytime I start and shut the engine Off repeatedly. There is No interaction between the sensors and the reluctor ring, No disturbance of the sensor wires.
2) If it actualy is an erraticproblem with the sensors then why don't the ABS light come On when I am driving a short distance or on a long trip? If there was a failure or problem in the sensor circuit, wouldn't you think the ABS light would come ON or maybe ON/OFF and set a code when the vehicle is going down the road?

Just to note, I have inspected the sensor wires for rubs, breaks, pinching, etc. I have checked the sensor wiring connectors and even cleaned all ABS connectors and plugs with an electrical contact cleaner. I reallylogicaly think that this problem is rooted in some type of control module or maybe the ABS computer itself. I know that any repairs to the ABS will be expensive, however I do not want to find out that replacing thewheel bearingsdid not correct the problem and then buy a new ABS computer, or visa-versa. Help me PLEASE.........Connie Sue

 

Dirty sensors will cause the ABS to engage unnecessarily and should not be blamed for lights popping on every so often. This would indicate that the system has sensed a fault. This could be caused by something as simple as a dirty connection on one or more of the plugs for the ABS control module.

ABS system codes cannot be checked with a typical scan tool.

 

Thanks swartlkk, Kinda like what I am thinking. I did check and clean the ABS sensor connectors (x3) and the two plugs at the Kelsey-Hayes unit by the firewall. Are there/is there any additional points that I may be able to inspect/clean? I had AutoZone do the scan, I only assume that they would have the right scanner outside of going 60 miles to the Chevy Shop. Also, are the sensors checkable with a pretty reliable VOM? You wouldn't by any chance have the specs, would you? Any other suggestions? I kinda have a limited time frame to work with before myTemp Tag expires. I will not be able to compleate MD inspection with the lights ON, and get my permanant plates......... Connie Sue

 

Autozone does not have the scan tool to read these systems. Their scanners can only read the 'P' or powertrain codes, not the 'C' (chassis), 'B' (body), or 'U' (network) codes. Your problem could be a problem with the ECBM itself, but the only way to tell would be to know what the chassis codes are.