Storm33

I thought the adaptive cruise control comes standard on a Prestige model.

DUTCH VanAtlanta

Not on this 2015; and I'm happy for it. The less "nanny" junk on my cars, the happier I am.

Force-1

Not on my 2011 or 2014.

Edd W

My guess is a faulty brake light switch. They are notorious for failing on quite a few VAG cars so I guess that the Q7 could fall into the same category.

It will not show anything in the log because it simply reacts as if the brake pedal has been pressed.

I would ask the dealer to fit a new brake light switch. It's a cheap part and quick to fit - 15 mins max and it could well solve the problem.

DUTCH VanAtlanta

A good idea, but. . . . . . .

If the switch stops the cruise control, it should be able to be restarted right away; and not require stopping the car, shutting down and restarting the engine in order to enable cruise control again.

I'm going to live with it until it fails completely. That way the problem should be easier to find and fix - even for a dealer tech.

smith2010Q7

That is true Dutch, but what have you done is shutting down the ECM which the CCS system gets it readings, once turning off the Car will also clear the problem. The brake sensor sends the reading to the ECM to shut down the Fly by wire throttle. The ECM will not turn back on the CCS until the brake sensor is not active, which it is still telling that it is still active until the car has been shut off.
We all know the brake sensor is not on when trying to reset the CCS, but the ECM is reading something different.
Hope I somewhat explain

JKJ

Just for the record, ACC was discontinued for the 2015 model year in the US on the Q7. I couldn't get a straight answer from AoA as to why.

DUTCH VanAtlanta

Not sure I understand where you think the problem lies. Is the brake sensor the brake light switch, or is it one of the sensors located on the individual wheels?

If it shuts down the fly by wire throttle, how is it possible to continue driving the car with my foot on the gas pedal and no cruise control?

pchansen

I have to admit it- I love ACC. Ive had it both my Q7's and its becoming a crutch. The only problem is I've almost rear-ended someone in my Jeep waiting for it to slow down on my own.
As far as the CC being intermittent, have them check the trailer towing module. Mine failed on my '07 and CC (ACC) was disabled. Not sure if CC and ACC would be the same with regards to having a trailer hooked up but it's at least worth a mention.

DUTCH VanAtlanta

Thanks. Not towing when it quit on me.

Dealer Service Manager wants me to bring it in for a scan. This, even though the VAG-COM showed no faults. He says that his system shows a whole lot more information than the VAG-COM. I guess I'll see what that shows.