Carpokes Porsche Forum

Ok so this Cayenne experience is not going so hot...

We've owned the car for 2.5 days now and already getting this message:

ACC not available
Driving permitted
Service necessary

The car is a 2020 base model with a 3.0L engine and just over 100k miles.

Wondering if others have had this come up and what it might be caused by.

Google tells me it could be a sensor or low battery.

I checked the battery voltage and it shows 13.3v with the car off so I don't think it's a low battery issue.

My wife drove the car to work and back home today and it was fine. Then after dinner she got in it to run up to Target and that's when the message first surfaced. She spent some time at Target and came home and it was still on.

We waited about a half-hour and I got in and took it for a spin. stopping and turning off the engine a few times and it stayed on and hasn't gone away.

Makes me wish I wouldn’t have bought the car.

Any help would be much appreciated!

Have you checked the sensors for road debris and gunk? I had something similar in my 992 -- not specifically acc -- and it turned out to be a dirty lens...

Sorry it's being a pain either way.

well I checked the windshield for debris and there is none. there's a camera on the front grille that looks similar to a rear back-up camera. that looks nice and clean. there was a fragment of a bug on the radar dome thing also in the grille. I haven't started it since removing that didn’t help either. not sure if/where any other sensors would be?

Your ACC error could be due to a misaligned sensor (that radar-like thing you mentioned in your post) rather than a failed unit. I had an ACC error on an earlier Cayenne due to misalignment.

I found this via a quick search. The info presented seems legit but it would need to be verified. From my experience and as mentioned in the piece, correcting it 'requires mandatory professional calibration with Porsche-specific equipment'.

https://www.go-parts.com/garage/cruise- ... -2019-2020

someone recommended disconnecting the battery for 30 minutes and trying it.

1. I'm not exactly sure how to do that.

2. I feel like that could cause other issues

Has anyone ever done this?

I think the link I provided in my previous post likely outlines what's happened as well as the correct approach to get it corrected.

"2019-2020 Porsche Cayenne ACC Sensor Failure: Understanding Warnings and Calibration"

Brought the car in to the dealer. they ended up seeing a fault on the radar sensor. They were able to just recalibrate it and it's working again now.

notny41 wrote: Thu Sep 03, 2026 8:05 am Brought the car in to the dealer. they ended up seeing a fault on the radar sensor. They were able to just recalibrate it and it's working again now.

That's great to hear.

I have experienced the same thing on a previous Cayenne and it also turned out to just need recalibration. Was hoping yours would turn out to be the same rather than a failed sensor or something else.

interesting, how long did the recalibration last after they did it?

notny41 wrote: Thu Sep 03, 2026 9:27 am interesting, how long did the recalibration last after they did it?

For the remainder of the ownership time on that particular Cayenne - maybe another year or two? I've only had it happen once. (ACC is also common on other newer Porsches as well as similar systems throughout the automotive world these days.)

As the article I linked earlier pointed out (and there are plenty out there like it), something as minor as towing or an alignment issue or other unpredictable things can create a situation where recalibration is necessary. So many of the sensors, cameras, suspension, etc are joined at the hip anymore, the case for most new vehicles these days. Many things to go wrong, unfortunately.