I have a 2001 Gmc jimmy. I know 2001's seem to have issues with the ABS system. Ive had a problem for about two months where the ABS light an BRAKE light would go on once in a while and it would stay on for about 2 runs and then go off for a month and keep doing that in a pattern. Now, If I let the truck sit for a while, like overnight, the lights aren't on. But, if I start the truck, turn it off, and then start it up again the lights will be on and it will stay on untill it sits for a while again. Did anyone have a similar problem or have a suggestion of what to check? I dont want to give the dealer $100 just to check the code, but who ever wants to give the dealer money Thanks

 

A lot of part places will scan it for free, shop/call around. In my history I've found that to be the ABS Sensor having an issue. Does it get mushy from time to time & then the light pops on, or you'll actually feel the ABS kick on around 10mph or less?
Search in here for ABS Sensor in 2nd gen or DIY. You'll find a DIY (Do It Yourself) for cleaning the ABS sensor or a write up about it.

 

My 2004 Blazer started acting the same way a couple months ago...
I checked with my local auto parts stores, to see if their (free use) code readers would read ABS codes, but none of them did...
You MUST know what DTC you're getting to start the troubleshooting process...
I searched out the best price I could find ($100) for the Actron CP9449 ABS BrakeScan Tool and ordered it...
My DTC code was C0265...
I'm currently in the process of elimination right now (inexpensive and / or easy things first) to get this fixed...
Maybe you know someone who has an ABS scan tool you could use, or maybe there's a local high school or college auto repair class that would help you diagnose it...

Hope this helps...

 

Guys. I had problems with my 2000 blazer 4x4 abs/brake for months. Did everything. Both front wheel hubs with sensers . No fix. But I remove the ABS module and call 507-429-4489. They fixed it for $55 and works like a champ.