2002 ST ABS pump won't turn off! 4-wheel drive won't work. Please help

[George Malian]

Hello all. I was wondering if I could get some advice please. One of my ABS sensors was bad and I could feel a pulsation every time I hit the brakes. They would still function okay, just with the slight pulsation at the end. My friend told me that he would put it on his computer to find out which one was giving me the problem and made an appointment to meet with him next week. However, when I pulled into my driveway, I could hear what sounded like the fan motor but when I opened the hood, I found my ABS pump motor was still running (even with the key off). I would not shut off so I disconnected the plug to the pump to prevent my battery from draining. I got back in the truck and took it for a ride to see if the brakes would still function with this disconnected and it did and I didn't feel the pulsation anymore.



Today we got some snow and when I put it in 4 wheel drive, I noticed that it didn't work. I also didn't have the light on the dash that tells if it's in 2wd or 4wd. I checked the fuse and it was okay. I then thought that maybe it was related to that ABS pump plug that I disconnected so I plugged it back in. The pump began to run again but that didn't make a difference in the 4wd because it still didn't work. Does anyone know what the problem may be with the ABS pump AND the 4wd? Any help would be greatly appreciated. Thanks in advance. Malo

 

[Kevin Palmer]

The 4WD issue is likely the module that is located under the dash. If you do a search on it, you will find PLENTY to read about it..

 

[scott degroot]

The abs issue sounds like you are going to need a new abs control module, easy to replace but it will have to be programmed. For the 4x4 issue, check the #13 fuse in the engine compartment, if it is ok then chances are that it is the 4x4 module under the dash

 

[Dreman]

Leaving the fuse out won't disable the brakes, but it will disable the anti-lock. Don't know about the 4x4. I had a 1999 GMC Sierra that the abs module went out on. Common problem with them. I pulled the fuse and it actually stopped BETTER. Any little bump would set off the ABS, and without it the brakes stayed on. I had to be more careful in rainy and snowy weather, but dry braking was definitely better. I drove it like that for almost 200,000 more miles. I'm not suggesting that you do that, but your brakes will still work.