2017 Q7 hesitation
12-11-2018, 08:26 PM
#1
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2017 Q7 hesitation
So I'm having an issue with the vehicle experiencing a slight hesitation when transitioning from no load ( i.e. coasting ) to a acceleration. What happens is the car will be coasting or maintaining a constant speed and I will start to slowly accelerate and there will be a very quick drop in power and then every thing is OK. It feels like a single misfire. Its very repeatable and always happens only once on the transition. Once passed the transition I can accelerate normally with no issues until I let the vehicle coast and then slowly start pressing on the gas where i can repeat the issue. Any thoughts.
12-12-2018, 04:49 AM
#3
I haven’t experienced this with my Q7, but had it all the time with my ‘17 Honda Ridgeline. The SA explained that the mapping in the adaptive transmission control module changes depending on your driving pattern; sometimes it gets corrupt and needs to be reset. They initially reset the module when I complained about the lag, but now it’s at the point where the service department does a reset every time when I bring it in for any service as a preventative measure. It seems to be a bit excessive but it’s probably cheaper for them to do a “goodwill” reset than it would be to replace the control module, and the problem is gone.
I know it’s a different system, but maybe a reset would solve the issue in your case as well?
I know it’s a different system, but maybe a reset would solve the issue in your case as well?
12-12-2018, 07:43 AM
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@Spaceframe havent tried sport mode but I have tried manual shift and it still happenes. It also more noticeable when assessing mountain roads but I think that’s more due to the physics than an increased severity of the issue. A quick and sudden loss in power would be immediately noticeable when going up a steep hill, on flat terrain the problem is bearly noticabe. I’ll give it a try, sport mode holds the lowers gears longer and may make it more noticabe on the flat terains.
12-12-2018, 07:49 AM
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@GHSB: I’ll have to try that on my next service. I have had the memory cleared before but I’m not sure it made a difference. At the time I had not yes discovered how to reliably reproduce the issue.
12-19-2018, 08:14 AM
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Update for sport mode
Got a chance to test this in sport mode and the issue does not happen in sport mode. I think this is due to the computer holding the lower gears thus maintaining the engin in a higher rpm range. When in I’m manual shift mode if I hold the revs up (similar to when in sport mode) I can’t reproduce the issue either. If I try to manual shift the engine in a manner similar to how the regular driver mode does I believe I did feel the hesitation though it difficult to say.
09-09-2021, 01:58 PM
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Got a chance to test this in sport mode and the issue does not happen in sport mode. I think this is due to the computer holding the lower gears thus maintaining the engin in a higher rpm range. When in I’m manual shift mode if I hold the revs up (similar to when in sport mode) I can’t reproduce the issue either. If I try to manual shift the engine in a manner similar to how the regular driver mode does I believe I did feel the hesitation though it difficult to say.
Did you ever figure out what the issue was, and the fix? Please let me know. Thanks so much!Trending Topics
09-10-2021, 10:34 AM
#8
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Scan the car for codes and let us know what you find. I would bring to a reputable mechanic and see if you can reproduce the issue as well.
10-09-2021, 11:32 AM
#9
AudiWorld Junior Member
2017 Q7 91,000KM I am having the same issues. Sport mode cures the issue. Plugs have been recently been changed as well. I am wondering if anyone found the issue?
10-09-2021, 05:06 PM
#10
Hey guys....I had something similar to what you are describing with a "lack of power" or "hesitation" or something to that effect when I acquired my '17 Q7 a few months ago. I initially thought it had something to do with the transmission and shifting but after I realized it was load dependent I shifted my focus to the supercharger clutch. It did end up being a bad supercharger clutch (I am assuming everyone posting about the issue has the 3.0T?). I was able to find supercharger clutch failure codes stored in the fault memory with VCDS. It was under CPO warranty so Audi diagnosed bad clutch and replaced under warranty.
The clutch is not engaged 100% of the time, for fuel efficiency apparently. It is my understanding that the clutch going "bad" means its just worn to the point of either engaging roughly or slipping. But in sport mode it is either engaged all of the time, or it engages much sooner in the load map -- so that in sport the rough engagement is not as noticeable. In normal "D" mode it can be engaged at high enough rpms that as your requesting more torque (with your foot) it can jerk the whole driveline enough to feel. As a side-note, the technical literature provided for the CREC EVO engine mentioned that simply an ON / OFF clutch engagement for the supercharger would provide something like an "instant" additional 40nm of torque on the engine and be capable of being felt by the passengers. They therefore use a PWM signal to engage the clutch more softly to smooth out the additional load. The new clutch got rid of the jerk sensation but I can still feel the supercharger come in when driving in "D". I am usually in "S" or "Manual" mode because of that -- I cant stand feeling that and the fact that the transmission shifts like its attached to a diesel engine.
So what your feeling might be the SC clutch -- look into it if you can.
The clutch is not engaged 100% of the time, for fuel efficiency apparently. It is my understanding that the clutch going "bad" means its just worn to the point of either engaging roughly or slipping. But in sport mode it is either engaged all of the time, or it engages much sooner in the load map -- so that in sport the rough engagement is not as noticeable. In normal "D" mode it can be engaged at high enough rpms that as your requesting more torque (with your foot) it can jerk the whole driveline enough to feel. As a side-note, the technical literature provided for the CREC EVO engine mentioned that simply an ON / OFF clutch engagement for the supercharger would provide something like an "instant" additional 40nm of torque on the engine and be capable of being felt by the passengers. They therefore use a PWM signal to engage the clutch more softly to smooth out the additional load. The new clutch got rid of the jerk sensation but I can still feel the supercharger come in when driving in "D". I am usually in "S" or "Manual" mode because of that -- I cant stand feeling that and the fact that the transmission shifts like its attached to a diesel engine.
So what your feeling might be the SC clutch -- look into it if you can.