Jim Grant's Tech Tips
‘01 Chevy Tahoe, None Stop ABS Pump
Underneath my ’01 Chevy Tahoe I heard something constantly running just under the driver seat on the frame. I needed to stop it and found that when I removed the 60 amp ABS fuse it would turn it off. When I put the fuse back in, it would run again.
From your description it sounds as if the Antilock Brake System’s pump is not turning off. The ABS has a computer called an Electronic Brake Control Module (EBCM). When you remove the 60 AMP ABS fuse, you’re removing the power supply from the EBCM. The EBCM just happens to control the ABS pump. If the ignition key is in the off position and the ABS pump is still running it is likely that the computer “EBCM” that commands the pump’s operation has an internal electrical problem. Have a qualified technician inspect and perform a computer check of the ABS computer. In the event that the EBCM is the cause for the problem, it is replaced as an assembly. The assembly includes the computer, pump, control valves for the ABS system and is a pricey unit. The ABS pump is not designed to be running all of the time and will eventually fail. Once the pump fails the ABS system will be inoperable.