Kiwi Carguy

Hey everyone. I've recently sold my 957 Cayenne to a friends son and the "check brake lights" warning has come up so I want to try and help him sort it. I've read through the searches and there's varied views from the 3rd brake light LED failure to potentially the main battery of the car needing replacing. Is there any way to check either without replacing them. Don't really want to spend $650nzd on a battery or $300nzd on a LED brake light only to find out it was the other.

Harry Apps

Simple check:

1. Use a broom handle (or similar) between the seat and pedal to activate lights
2. Walk around the rear and look.
3. Check battery voltage

957GT-YES

I get the same message, but randomly, maybe once every other week. I replaced the battery a couple months ago so I know it isn't that. If the message is consistent, I'd consider the battery. Also, are you showing other signs of low battery? If it's intermittent, I'd lean toward one of the brake lights. My brake lights are working fine, but I forgot to check the 3rd one. I'll be checking that the next time I see the message. Cheers!

crunchyfrog

I have had the same message on my 957 as well.
Did replace battery as it was weak but this did not solve issue.
Whenever I checked the lights they were all working. However, at a recent WoF (warrant of fitness) check they failed the 3rd brake light as it was not working.
I removed the light - it is a sealed unit. With a dremel tool I opened the unit up.
I discovered that where the terminals for the plug joined the circuit board the soldered joints were broken (probably due to vibration).
A broken joint would give a high resistance which would cause the Check Brake Light error but might still allow the light to work.
I resoldered the broken joints and glued the unit back together.
3rd brake light now works as it should and the Check Brake Light error message has now gone away.

Libast

the third brake light may be having issues via water intrusion or some of the LEDs going bad