According to the service manual, the following are potential causes of a P1572 code:
- Misadjusted brake switches, BPP or BPA
- Blown fuse
- Damaged BPP switch
- Damaged BPA switch
- Open or short in BPP circuit
- Open or short in BPA circuit
- Damaged PCM
Obviously you hope it is not a damaged PCM. The code is triggered when the PCM does not see the proper sequence of the brake pedal input signal from both the Brake Pedal Position (BPP) and Brake Pressure Applied (BPA) when the brake pedal is pressed and released.
The BPP should be pretty easy to test, but I'm not sure about the BPA. I'd have to look over the diagrams a bit to determine how hard that would be to test.
If you'd like me to send you a PDF from the service manual regarding troubleshooting this code, private message me with an e-mail address for you that can accept attachments.
BTW, you need to update your profile so I can see what year your LS is. You currently just have the SVT listed. I had to review your old posts to determine you have a 2001.
-Rod