What causes an ABS light to come on?

[TerryMason]

I've got a Silverado that I'm trying to sell, and it's got the ABS light lit. I'm not really up on the ABS system, but are there a few cheap / free things that I can check to see about fixing this?

I was surprised to find that my state (Virginia) doesn't fail inspection for an ABS light, so I don't have to fix it.

 

[JPNinPA]

On some vehicles if the abs light is on it disables abs.

There likely is a way to read the codes for the abs with and without a code reader.
Go the code reader route first. On some model year Honda vehicles you ground one of the pins on the code reader connection with the key off. Turn it on and count the abs light blinks. Idk but see if there are ways yo get the abs codes.

Possibility for codes includes but are not limited to
a bad wheel speed sensor.
A dirty or broken tone ring.
In some cases the wheel bearing is the speed sensor and is about to cause issues.
There is a sensor in the fluid reservoir
Low fluid
Bad connection
Stuck float.
Did you bleed the breaks?
Air in the line
There usually is a way to bleed the abs system.
Low brakes

 

[TerryMason]

Thanks. I'm not looking to change a bunch of speed sensors, but I'll look into the fluid / stuck float thing.

 

[dwillys]

You say you don't have to fix it but,it won't be an easy sell with the light on. I hope it's an easy and inexpensive repair

 

[JPNinPA]

Read the codes!

http://www.aa1car.com/library/abscodes.htm

 

[TerryMason]

It appears that this truck (01 Silverado) only has ABS on the front wheels. I looked on the driver side and everything looked fine. On the passenger side the wire coming from the brakes was unplugged at the connector. I plugged it up and drove about 100 feet and the ABS light went off.

Looks like I lucked out this time.

 

[JeffMohr]

Not sure in a Silverado. But in a Jeep the ABS stands for Always been Sexy.

 

[JPNinPA]

Glad to hear you figured it out.