Downshift sudden and complete loss of power from 100km/h Audi A3 2.0T (PQ35, DQ250)

[toml]

Hello all,

I know, the A3 is not a Golf... However I thought it might be valuable for all putting this here to spread the word, the cars are on the same platform and there is a chance that one of you has had the same problem in a Golf. Moderators please move if you would like!

So, I have just purchased a second hand Audi A3 2.0T 8P which has been my dream for a little while now. Love the car but have got a serious problem with it that I need help on, you guys have the most experience from my google research.

The problem started like this - Driving along for an hour at 100km/h with cruise control set when I hit a hill on the highway. While climbing the hill the gearbox kicked down a gear into 5th and accelerated to maintain 100km/h. The moment 100km/h was reached and the car stopped accelerating, the 'ESP' dash light stayed solid, the car reduced to idle, all engine power was lost and the throttle was unresponsive. A restart fixed the malfunction. (In the middle of the highway, it was a terrifying experience)

I was able to replicate the malfunction on a steep hill at lower speeds in the following way: cruise control set to 50km/h, engine hot, let car slow to 45km/h, trigger downshift, car accelerates to 50km/h, acceleration stops (slight deceleration), 'ESP' Light, no power. At idle, in a safe place I was able to keep the car in it's no power state, the car wouldn't rev past 1600RPM. The car sounded like it was not firing on all cylinders but maintained idle ok.

I'm curious, has anyone else experienced these exact symptoms in this car or a car on the platform? I would be very grateful to find out what caused the problem and how it was able to be fixed!

Thanks all,
Tom

Car Information
Make:	Audi
Model:	A3
Version:	8P (2003-2012)
Year:	2005
Engine Type:	2.0 TFSI, 1,984 cc (121 cu in) I4, "AXX" 200PS (147kW; 197hp) @5100-6000, 280 N·m (207 lb·ft) @1800–5000, 2004–2008
Gearbox Type:	DQ250, (6 Speed DSG)
Platform:	VW A5 (PQ35)
Other Cars on Platform:	Audi A3 Mk2 (8P)
	Audi TT Mk2 (8J)[1]
	Volkswagen Touran (1T)
	Volkswagen Caddy (2K)
	SEAT Altea (5P)
	Volkswagen Golf Mk5 (1K)
	Škoda Octavia Mk2 (1Z)
	Volkswagen Golf Plus (5M)
	SEAT Toledo Mk3 (5P)
	Volkswagen Jetta Mk5 (1K)
	SEAT León Mk2 (1P)
	Volkswagen Tiguan (5N)
	Volkswagen Scirocco (13)
	Volkswagen Golf Mk6 (5K)
	Škoda Yeti (5L)
	Volkswagen New Compact Sedan (1K), (16)
	Audi Q3 (8U)
	Volkswagen Beetle (A5) (16)\
	Volkswagen Eos

[Sam]

Rather than spread replies across multiple forums, I'll lock this one and ask anyone with any info to respond here;

Downshift sudden and complete loss of power from 100km/h Audi A3 2.0T (PQ35, DQ250)