2004 Silverado ABS light

[ssspencerjr]

Rolled my Silverado up on ramps to change the oil yesterday, fired it up to bring it off the ramps and th abs light came on and hasn't gone off, with multiple trips places. Any ideas on what I should look for? Brakes feel fine during normal use.

 

[GMBoy]

You need to scan for chassis codes and go from there. In all likely hood it will be a wheel speed sensor.

 

[Snagglefoot]

Perhaps you nudged one of the wheel sensors when you where crawling around underneath. Where you dong any grease gun work?

 

[ssspencerjr]

Perhaps you nudged one of the wheel sensors when you where crawling around underneath. Where you dong any grease gun work?

Nope, strictly oil and filter. I may have touched the actual tire but for me to hit a sensor would be amazing, the truck is high off the ground as it is, even more so on ramps.

 

[Redright9]

Do you have a code reader? May need to reset the codes to get it to go away (or at least it will point you in the direction for the fault). Any chance any animals have chewed any wiring, I have had some problems on my vehicles with animals chewing my wiring....

 

[Snagglefoot]

I think would disconnect the battery in case it’s just some freaky random non issue.

 

[ssspencerjr]

Do you have a code reader? May need to reset the codes to get it to go away (or at least it will point you in the direction for the fault). Any chance any animals have chewed any wiring, I have had some problems on my vehicles with animals chewing my wiring....

I have an el cheapo bluetooth one, honestly haven't put it on yet, I don't even know if it reads abs codes. I'll do this tonight.

 

[czbrian]

Doesn't the GMT800 trucks have a common issue with the ABS modules going out due to solder joints cracking? I think there is a certain code thrown that indicates this.

 

[cb_13]

Doesn't the GMT800 trucks have a common issue with the ABS modules going out due to solder joints cracking? I think there is a certain code thrown that indicates this.

Yes. The same person soldered them that soldered the instrument clusters in the 99-03 F150's.

 

[AutoMechanic]

Did you go up on the ramps hard? I know that when I worked at a previous shop we had the drive up on lift on one bay and I come up on it once and it shook the sensor a bit and made the light illuminate. I just reset it with a scan tool and it was fixed.

 

[JMJNet]

You can check the resistance (ohm) in the Wheel Speed Sensor, it has fluctuate to be within a certain range.
It may be just dirty.
On the older GM Truck, it is attached to the wheel bearing/rotor.

 

[ssspencerjr]

Did you go up on the ramps hard? I know that when I worked at a previous shop we had the drive up on lift on one bay and I come up on it once and it shook the sensor a bit and made the light illuminate. I just reset it with a scan tool and it was fixed.

I did not, I have a set of race ramps so it's easy to drive up.

 

[eljefino]

Went through this on a chevy cavalier and olds silhouette. The wheel sensor connectors stress the wire, the wire takes a 90-degree turn coming out of there and can break the copper strands inside the insulation. Do some continuity checks.

The wiring pigtail is "common GM" found everywhere on the engine too. Grab a few from the junkyard.

 

[supton]

Didn't GM also have the problem where rust would push the sensor away from the ABS wheel?

 

[clinebarger]

Doesn't the GMT800 trucks have a common issue with the ABS modules going out due to solder joints cracking? I think there is a certain code thrown that indicates this.

That was more of a '99-'02 problem as was the pump relay sticking on.

 

[Driz]

One of the sensors on my 2000 Sierra was busted off when I got it in 2013 7 years later it’s still that way. Who cares , old truck that works just fine otherwise. There once was a world without automatic brakes and the world kept turning just fine. Even the Peoples Republic hasn‘t noticed that one yet for their annual inspection (torment).
GM really hit it out of the park with that era trucks . Not only was the frame made of tinfoil but those brake cylinders. Who ever heard of a 13 year old brake cylinder rusting completely through.

 

[jhs914]

Doesn't the GMT800 trucks have a common issue with the ABS modules going out due to solder joints cracking? I think there is a certain code thrown that indicates this.

This ^. The module sits on top of the frame rail just under the drivers door. The solder used in the module deteriorates with age and looses it's connection. New modules are $$ but there are places that can take them apart and re-solder.