jimdolian

I have a 2016 SQ5 and have never experienced any of these issues. However, I live in a very dry climate and don't have to drive much in heavy rain.

Redd

Unless I've been misinformed (again) first of all there are no sensors "in the brakes". There is one "worn brake pad" sensor, to tell the car that you need new brake pads as they wear thin. BUT there is also a sensor for the ABS system ON EACH WHEEL. It is not "in the brakes" but it is part of the ABS system. This sensor basically counts the number of gear teeth passing it on the wheel assembly as the wheel turns, and it does that in order to tell how quickly each wheel is turning. That information is passed to the ECU, and it traditionally is used to tell the ABS system that one or more wheels is turning at a different rate, to apply the brakes to slow that one wheel, or to pulse the brakes, to brake the car during a skid. Audi also did a bit of engineering elegance by using this system to say "Hey, this one wheel always is turning too slowly, it must be going flat" so you can get a low tire pressure (TPI) warning without the need for any extra parts actually inside each tire.

Now, the OP mentions going through a puddle. DING! Light bulb should go off here. Go through a deep puddle at speed, and water will splash all over each wheel well. And it will splash into the ABS sensor and the ABS sensor wiring harness. What happens when the sensor shorts out from the water? And generates some crazy out-of-bounds signal to the engine?

I'm guessing the engine says "That's not right!" and throttles back. NOT ENGINE BRAKING, which can cause a car to skid and places excess wear on the cylinders. Simply loss of throttle response, because the engine is getting an error signal from an ABS sensor.

I would run that past the service writer and specifically ask them to either A) replace the ABS sensors and harness or B) to get a firehose (not just a garden hose) and flood the **** out of each sensor assembly until they find the one that kicks out and slows the engine down.

There would be no error code thrown off, since this is just a "routine" ABS operation, even if the engine is being confused by the loss of one ABS signal, I'm guessing.

Since this would be damned hard to test and confirm, the dealer MAY be able to get Audi to authorize replacing all four sensors, or at least, one axle pair at a time.

I would also suggest filing an incident report with the OP's national authority (that's the NHTSA in the US) to put them on notice that driving through puddles can cause throttle failure in the car. This may not be the only car with this problem. Or, it may be the result of damage from some mechanic who did improper work on the brakes or wheel well area.