WP4WP4

I have a new 2013 Q7 3.0 (not TDI) and it is in the dealer right now for the same problem. From a stop and pressing the gas pedal a delay of 3 seconds especially on a stop and go situation. It is randomly and the dealer cannot replicate the fault. I recommended the brake sensor from the post below. I will found out later today the outcome.

WP4WP4

Dealer called me; they are replacing the brake sensor to be safe and test.

Edd W

That sounds plausible - hope it is fixed for you!

Edd W

Not the same issue.

The throttle is backed off simply because it detects that the brake pedal is being pressed - it simple logic - if you are braking then you cannot be accelerating at the same time, so the throttle is backed off, even if you have your foot on the floor.

The fault here is that it sounds like the brake pedal switch is faulty causing the ECU to think you are pressing the brake pedal so it backs off the throttle.

Exactly what some Toyota's did not do!

VAG-Fan1

I know the Q7 has a brake pad wear sensor, but I didn't think it had a thermocouple embedded into it- my understanding is it is a simple open loop wear "switch" that is closed when the pad wears down and the sensor contacts the rotor to close the loop and report to the vehicle braking module the "wear" state. I'm curious how you came upon this explanation (i.e. dealer tech) and would like to know what sensing mechanism is being used to measure brake temperature. I don't doubt that the Q7 ESP system is really always monitoring wheel speed and accelerometer data, even when switched off, and will re-activate under certain conditions, I just had not heard of brake temperature being an input to the ESP system.

Edd W

I suspect it is an assumption based on some rather poor explanation at some point. I don't think there is any form of brake temperature sensing, it is probably based on a calculated brake temp based on the duty cycle of the ESP and ABS etc... - knowing Audi, it will possibly also take ambient temp into account as well, maybe even barometric as well!

Ifundum

I had the same issue with my 2012 Q7. Had everything checked per the other recommendations on this blog. They all checked fine. But, there is a part called the “ throttle body” which regulates the air into the engine. It’s both electrical and mechanical. Mine showed sporadic response on the computer. Mine had carbon buildup and didn’t open/ close correctly. We replaced it and it’s infinitely better. Here is another reason for the hesitation; riding the break petal or using the left foot on the break and breaking and accelerating at the same time. When the break petal is slightly pressed, it signals the computer and it cuts off gas momentarily. It was a bad habit of mine and once I started using my right foot for both breaking and gas, it was fine. With both those reasons solved, my Q7 is fine

Ifundum

Dont ride the break petal or simultaneously break and accelerate. Any pressure on the break signals the computer to cut off gas. Also, have the mechanic check the “throttle body”. Replaced mine and hesitation went away