1999 Silverado Abs Light On (even When Not Moving)

[lynchmob723]

I know this topic gets beat to death, and Ive searched quite a bit on here and other forums but I had another question. My ABS light is constantly on. I know it can be the EBCM, wheel hubs (speed sensors), or even the ground on the EBCM. In my case though, I can simply start the truck, leave it on for a couple minutes and the light will come on without me ever shifting out of park. Could this help narrow it down to what it could be? Makes me think it isnt a hub because ive check them, and there is no 6 to 12 play in it at all.

Ive played with the ground for the EBCM under the drive side door, and even grinding rust away under where the screw sits, however I cant get the screw to ever fully tighten, I can only get it finger tight, a wrench will just keep spinning it all day, almost like its stripped. The thing is though, if I just unscrew it, and start it, the light is on right away, along with the service 4wd drive light....so that leads me to believe it isnt the ground because it doesnt come on right away when the screw is finger tight. It always comes a few minutes after i start it even though im not moving in the truck..ala movement to jar the ground loose. Just looking for some opinions...Im thinking I need the module rebuilt.

[asc08]

Start by verifying that all grounds are properly installed. The one you checked is not properly installed. Use a nut and bolt if need be, but start there.

[txab]

You can have an ABS error code just turning on the key. Check your ABS sensors at the hub. they tend to develop corrosion causing the sensor not to work properly.

[grampadirt]

[quote name='txab' post='1209553' date='Oct 12 2011, 06:52 AM']You can have an ABS error code just turning on the key. Check your ABS sensors at the hub. they tend to develop corrosion causing the sensor not to work properly.[/quote]


+1 Happened to me on my '95.But pulling the hub was a pain(3/4ton 4x4).Cleaned all the crud & crap from the sensor and all was good

p.s. you might have a bad sensor

[Rons05z71]

It sucks that the wheel hub and speed sensor are integrated. Check the little wires. follow them up a good ways looking for a broken wire

[jblakeney]

And the DTC is?????????????? No code, no way to figure it out. Edgewise your just stabbing in the dark.

Jbo

[lynchmob723]

[quote name='USMdude' post='1210057' date='Oct 13 2011, 11:30 PM']And the DTC is?????????????? No code, no way to figure it out. Edgewise your just stabbing in the dark.

Jbo[/quote]


I had two codes. B0265 (EBCM), and B0281 (brake light relay or something to that sort) <-- like it was just telling me the "brake!" light was on. I had the codes pull at autozone, i dont understand why its starts with a B and all the codes related to the EBCM start with C on the boards.

So i clean the grounds up with wire wheel/grinder on the EBCM ground, and the ground from the frame to the battery. Light still comes on

This is the scanner auto zone used [url="http://www.autozone.com/autozone/accessories/Actron-OBD-II-and-CAN-AutoScanner-plus-tool-with-CodeConnect-and-ABS-displays-for-1996-and-newer-vehicles-trilingual/_/N-25iq;jsessionid=426C3272BCC6F851F0220EF424170E42.diyprod4-b2c14?counter=2&itemIdentifier=61988_0_0_"]http://www.autozone.com/autozone/accessori...fier=61988_0_0_[/url]

[ChevyTech77]

If, you have those dtc's, and you have a good power and ground supply to the ebcm, and your abs pump motor is not faulty (drawing too many amps) then you need an ebcm.

[lynchmob723]

[quote name='ChevyTech77' post='1210153' date='Oct 14 2011, 10:52 AM']If, you have those dtc's, and you have a good power and ground supply to the ebcm, and your abs pump motor is not faulty (drawing too many amps) then you need an ebcm.[/quote]

Thanks, Ill check the voltage

Another thing to note, When the abs does activate, It starts out good..making the typical abs noises, then it fades away/stops working. It makes it hard to stop because pumping the brakes doesnt help, probably because the system thinks the abs is working, but it isnt, so its like im applying the break and but its not braking, kinda dangerous. Im just going to pull the fuse for the time being