The ABS on my Blazer 4WD 1998 works not properly in low speed. The brake pedal hits back and sometimes the ABS control lamp lights up. I've already changed the ABS speed sensor on both front sides but nothing happened.

Thank you very much for your support.

 

You can try this: http://ww2.justanswer.com/uploads/GM...s_bulletin.pdf

If that doesn't take care of it, you will need to get the diagnostic trouble codes retrieved, (requires a scan tool capable of accessing ABS). Post them here and we can help.

 

An easy thing to check is for play in your front hub bearings. Jack up the front end & grasp each wheel at the top & bottom & try to rock it back & forth. If you have play then that will upset the gap between the ABS sensor & the toothed pulse ring within the hub. This is exactly what happened to mine & it made the ABS act up in just the same way you are experiencing. In my case the drivers side hub was bad, a new assembly cured the problem - even better was the new hub came with a new ABS sensor so before I disposed of the old hub I took out the sensor to keep as a spare. I haven't yet needed it but you never know?

 

Ok so I had some serious ABS issue. I tried replacing hubs, ABS sensors, shimming the sensors, nothing worked...

What I ended up doing was removing the ABS control module, popping it open, and checking all the solder joints on it. Atleast half of the solder joints on the circuit board were cracked, which ends up giving bogus signals, which caused my ABS to act all stupid.

I resoldered all the connections on the circuit board, resealed the ABS box shut, reinstalled it, and haven't had a problem with my ABS since...

Here's the video I watched (I know its for a Jeep, but it's all the same concept.) ...

You have to be stupid careful. It took me about an hour to take it out, open it, fix it, and reinstall it. TOTALLY worth it, my ABS works perfect now.

 

Where is the ABD control module at?

 

On my 2001 Blazer LS, it's under the hood on the drivers side.