PO571

[shamirj]

So having probs with my D4 Tdv6 - got the 3 amigoe errors ran my scan gauge and was told it was the brake switch - so first checked all the front and rear light globes all ok, then checked and replaced the 5amp fuse for the brake switch, then replaced the brake light switch with a new one, then did a hard reset by connecting the two battery clamps (unconnected to battery of course). The error message says 'brake switch A circuit'. I have ordered another brake light switch and will refit another. My replacement one was blue and brown colour instead of the blue and white as per original. Otherwise it will be off to the mechanics for something which might be simple to do at home. Battery is under 12mths old. any help appreciated.

[DiscoDB]

If the wiring is anything like the D3, then check for a damaged wire or splice on the brake switch circuit. On the D3 a common failure point is a splice under the passenger door sills. Also check connectors, and earth points.

Hopefully not a case of fitting a faulty new replacement brake light switch.

[libertyts]

Adding to what DiscoDB has said, if there is an electronic brake controller on the car, follow it's wiring and check it out. There are some real cowboy installers out there.

No other fault codes at all? I had this code amongst others the other day when the alternator packed it in. It set all sorts of things off.

Good luck chasing the problem down. I feel your pain, seems like all I'm doing is chasing issues at the moment. Doesn't help that the CAN Bus computer network setup causes unrelated codes to be thrown.

[shamirj]

In the end was a dodgy brand new brake switch - i had previously bought a brand new one but the colours were the blue and brown on the casing not blue and white as per the original. Purchased a new one (blue/white) and it worked. cleared all faults, brake switch was not the only error code thrown up a whole heap of others popped up as well. glad to have saved a trip to the mechanics for such a simple repair.

[DiscoDB]

In the end was a dodgy brand new brake switch - i had previously bought a brand new one but the colours were the blue and brown on the casing not blue and white as per the original. Purchased a new one (blue/white) and it worked. cleared all faults, brake switch was not the only error code thrown up a whole heap of others popped up as well. glad to have saved a trip to the mechanics for such a simple repair.

That’s a good outcome in the end.

[libertyts]

Great to hear mate! Yeah, you would have ended up with a few different codes thrown because of it. Can make troubleshooting difficult some days.

Enjoy!