JohnBoyToo

It 'could' be driver error since accidents happen every day...

but just be aware now (shouldn't be hard with that fright!) and know that the electronic emerg brake WILL stop the car.... if u do it while parked and in a quiet place you will hear how hard it locks down the car...


You might consider trying to replicate the conditions (sans hill) to see if any combination will do that....

personally I don't like the foot on the brake to change the gear lever thingy either !

CrustyNoodle

Thanks for your reply and additional details. Unfortunately I have to say that it does sound like it might have been driver error... I'll explain:

The brake system in the Q5 (and pretty well every other car on the planet (yes there are exceptions - like diesel engine'd cars)) uses vacuum (negative pressure) to assist you in brake application (makes the brakes feel very powerful with very little pedal effort). The source of this vacuum is the running engine - if the engine is not running there is no evacuation of the brake booster and hence no brake assistance. When you first press the brake pedal before you start your car, you will find that the pedal feels normal and powerful but if you press it a couple of times without the engine running you will deplete the vacuum store and you will feel the pedal get really hard (try it for yourself - with the park brake applied of course) - I bet this is how the pedal felt during your NDE.

Given your more detailed description I think the engine probably wasn't running (was the steering also hard to turn?). The fact that the transmission wouldn't change into park whilst you were already on the move is not that surprising as it protects itself from doing things that are likely to damage it (like engaging park whilst on the move).

At the end of the day you have a very beautiful car that is amongst the safest on the planet so please don't be disheartened by this experience and don't take the stupid advice of those that make comments like "sell it" and "tell AoA about the "problem"" they are not helpful comments and will not solve your problems - just cause you anguish!

Finally, if you ever find yourself in this situation again (I'm sure you will not) then make sure you push the brake pedal with ALL your strength (eg as hard as you can with both feet) and if you do have the presence of mind then apply the park brake (don't engage park gear).

Enjoy your Q5 and I hope you have many happy years of motoring in it (at least until the world runs out of oil ).

Jusforfun

Thanks for elaborating. It does sound like the engine was running at least initially. The problem with the "digital park hand brake" is it automatically releases if you drive against it, so not much use to you. If anything it would act against you on this occassion... unless you flicked it again in which case it would hold.
Your event sounds quite traumatising.
I have had one similar event in my Q7 when I started and shifted at the same time. It had just fired up but I shifted too quick which stalled the engine. As I was not in park it didnt hold. As It was not in park I couldnt restart. As its automatic it just rolled. The only difference was I held my foot on the brake and the slope was very gentle.
I can imagine as Crustynoodle pointed out, without the engine running the brake pedal will get very stiff if it even had time to charge. Certainly you would not be able to put a rolling car in park as park is two gears locked together.
You can or could have re-started the engine in neutral once your foot is on the brake.

Just for your own peace of mind, With your car in PARK and engine off press and release the brake. Notice now how the brake pedal gets really high and hard without the assistance of the engine.
Now start the engine and feel how the brake sucks down abd gets softer under your foot as the vacuum from the engine builds.
For future reference make sure this is how it feels before you pull it from park.
Pretty much all makes and models of cars on the roads today behave the same way.
Also you could try (on level ground with plenty of space around you) drive away with the parking brake on to see it release itself, then re-engage it. It should stop and hold you from rolling speed. And you should get some warning light/lights.