P1572

[Y2KSVT]

Just got my first check engine light since owning the car for 7 months now. Got the free obd-II scan at Auto Zone yesterday, and it came up with a P1572 code, which says it's a bad brake pedal switch.

shorod, you may recall a previous thread I started about 3 months ago, where all hell broke loose with my rear end electrical stuff. no brake lights, no rear turnlamps, tail lights on full time, no trunk release through the key fob or dash button, no gas gauge, and the shift select wouldn't come out of park unless I had the key in auxillary mode first, with the button held down while starting the car. They diagnosed it as a bad rear control module. Ends up mine wasn't bad, but needed reprogrammed. Very strange what happened, but anyway..... we were thinking it might have been a bad brake pedal switch, but that wasn't the case. Now this is coming up. Anything else this P1572 code could be? Definitely the brake pedal switch? What kind of a job is it to replace this? Any diagrams anyone could post? By the way, this is an '01 LS8. Thanks everyone!

Mark

[shorod]

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

[Y2KSVT]

Rod,
Thanks for the quick reply! I'll send you a PM with my email address. As for my signature, I'll update that as well. But if you look at my last sentence in my original post, I mentioned that I have an '01 LS8.

Mark

[shorod]

Originally Posted by Y2KSVT

Rod,
But if you look at my last sentence in my original post, I mentioned that I have an '01 LS8.

Doh! My fault. I guess my caffeine hadn't kicked in yet. Sorry. The procedure is on its way.

-Rod

[Johnny turbo]

Hello Rod, I saw on an old post that you helped someone on a code p1572. My dads car has 75k miles, is in great shape and has had a check engine light on it for about 6 months. We saw that it was brake switch but had no ill effects on cars performance, or brake light application. Intermittently the shift interlock would be problematic but not for more that a few seconds. Well, now the epa test won't pass because the light is on and they don't seem to care that's it's not emissions related. I checked the switch, took it out and metered it and it works fine, no sticking, etc. there is a fsb for this code FSB 14557 but can't get to see it. can you give me an idea or send me the dope? Thanks!
John