Very weird fault!

[Billytheboy85]

New to the forum so be gentle! I have just bought a 58 plate a8 3.0tdi and I’m making my way through it in my normal ocd way. I found the boot release on the drivers door didn’t work and after some reading I discovered it was in valet mode. Turned the lock on the boot lid vertically and bosh! Excellent! Time for a beer. Went out the next morning and pressed the start button. Engine start and at the same time ‘pop’ goes the boot lid. What the?!? Stopped the engine, started her up and ‘pop’ again!! ! Shizza! Why the hell would the start button cause the boot to open?!? It reminds me of the video where the poor lads work mates had wired his horn up to the brake pedal.

anyone got a clue? I wouldn’t know where to start in vcds. Not even sure which controller to look at measuring blocks for the boot lid button. 

Put it back in valet mode but it’s going to bug me till fixed

thanks for any help :)

[Steve Q]

Welcome to the forum, you'll find the members on here are a friendly and helpful bunch :) 

The a8 d3 is a lovely car and I'm jelious :) 

Having the diagnostic equipment is a good start and worth doing a general scan just to see what fault codes flag up. My other advice would be to get an auto electrician to have a look as I suspect it's something straight forward. 

Cheers

Steve

[Billytheboy85]

13 hours ago, Steve Q said:

Welcome to the forum, you'll find the members on here are a friendly and helpful bunch :) 

The a8 d3 is a lovely car and I'm jelious :) 

Having the diagnostic equipment is a good start and worth doing a general scan just to see what fault codes flag up. My other advice would be to get an auto electrician to have a look as I suspect it's something straight forward. 

Cheers

Steve

Thanks Steve. Vcds has been my best friend for years and saved me a ton of cash.. just can’t seem to find out why on earth the start button would even be associated with the boot release?? It’s clearly an old fault hence some previous owner stuck his head in the sand by using valet mode to get round it. If there’s anyone out there that shed light on the wiring I would be in your debt!

[Envy]

Many of the switching circuits on modern cars are not on / off type. They now shift resistance or voltage levels that are read by Control Modules. Before investing in an expert my first port of call would be to find every assocated loom connector and clean the contacts on them from the boot release swich through the door loom connector onto the ECU you can get to on to the boot release mech. Sometimes just unplugging and reconnecting the interfaces will remake any "dry" connection. 

No guarentee it will work but its an easy test and worked for a mates Volvo V50 ECU and the Wifes Pug 307 leccy windows. 

Over time electrical contacts can oxidise and lose conductivity. 

Good luck...