ABS Malfunction

[ecfune]

I noticed that something weird is going on with my 2001 Suburban ABS Brake system. Once in a while, when I apply the brakes to stop, I feel the brake pedal pulsating like the ABS system is on. The road is dry and the brakes are not slipping. The pulsating pedal is very annoying because there is no reason for it it to be activated. What could be the culprit? Thanks for your replies.

[777stickman]

I would say that you need to hook it up to a scanner that's capable of accessing the ABS system. It then needs to be monitored when this happens to determine what the problem is. Keep in mind that most over the counter scanners are not capable of doing this.

Could be wiring, wheel speed sensors, ABS control module. No way to tell without a high end scanner looking at it.

If you do get some ABS codes please post back all the numbers. The numbers are more important than a description so we can look at trouble shooting trees.

[ecfune]

Thanks Stickman. I'll post the codes if I get it. Right now, I reset the system by disconnecting the battery. I'll find out if it does the trick.

[taillight]

You may not get any codes. Check the voltages at the wheel sensors at the speed you get the pulsating. They should be the same. Sometime even this is not enough and I have had to use a 4 chanel oscilloscope and compare voltages.

[Highlandlass]

Sometimes the pulsating feeling could be from warped rotors too.

[JimW1999]

If it's just pulsing at very low speeds when coming to a stop, say less than 5mph I think you have the same problem I do. Something to do with corrosion around the wheel sensors, PIA. I just pulled the fuse for the antilock system and it works as standard breaking system. It's supposed to revert to standard mode if a failure occurs. After almost kissing another car while parking I got the idea that it has a failure and is not picking up on it. I work with computers all day and know enough that the less times I have to put my life in the hands of the darn things the better. But then again I grew up knowing how the pump the breaks and don't recommend this solution to anyone, just letting you know it worked for me.

[MakeItADouble]

I had/have the same problem with my GMC jimmy. When I hit the breaks the ABS would engage, even at low speeds making it difficult to stop.

As a temporary solution I pulled the ABS fuse so that the brakes work "the old fashioned way".

I was working on my GMC over the weekend I found both ABS cables to be cut close to the hub assembly, at the point where the metal bracket attaches to the suspension. These are aftermarket hubs. I've no idea how this has happened? Anybody ever hear of that???

[jmatteo1]

Many have been recalled because sensors were affected by road salt, dirt etc. Check for this frequently, because some model years and VIN's were added to the original recalls.

[taillight]

Where can I find those recalls? Thank You