MY 2019 Cayenne Base Auto Start Stop (AS/S) is not working. Although I like it being permanently disengaged, should I be concerned?

The AS/S worked in the beginning, but after 1000 miles, it stopped engaging. The display shows that it is off although it shows active on the PCM screen.

The majority of my driving is in heavy stop & go traffic with frequent hills. At first, when stopped at a traffic light on a hill, the AS/S would not engage & a "hold" message would be displayed, but it would engage at traffic lights with fairly level streets. For the last few days, the AS/S does not engage at all & I am no longer getting the "hold" message.

I am not activating Sport or Individual modes & it is my understanding the Auto Start Stop has to be disengaged each time the vehicle is started. This may sound like a really dumb question, but does the vehicle learn our driving preferences? Or, is something causing the system to malfunction?

 

Ok...so I found the answer to my question on the Porsche website. Since I can't delete my question, I'll copy & paste the information from Porsche. I believe the Auto Start Stop is not working because it is crazy hot where I live & I'm using the AC on the max setting.

From Porsche:

Exceptional conditions for the Auto Start Stop function

The Auto Start Stop function is not available e.g.:

1. SPORT/SPORT PLUS mode active
2. PSM switched off or in SPORT mode
3. When maneuvering
4. When the "Maximum Cooling" function is activated
5. When the "Defrost windshield" function is activated
6. At high altitudes
7. While adjusting the chassis level
8. Trailer detected (bicycle carrier connector or trailer connector plugged in). The Auto Start Stop function must be deactivated manually if a trailer hitch from another manufacturer is installed on the vehicle.

The Auto Start Stop function is only available to a limited extent, e.g.:

1. When the demands placed on the air conditioning or interior heating are high
2. When the battery state of charge is low
3. On upward or downward slopes
4. During internal tests, e.g., automatic engine diagnostics
5. Very low or very high outside or battery temperature

Information
If one of these states occurs after the engine has been stopped automatically, the engine can be restarted automatically.

Switching the Auto Start Stop function on and off

Switch off


The automatic engine shut-off is suppressed.


Switching on


The engine is switched off automatically when the vehicle comes to a halt.


Auto Start Stop function display

Automatic engine stop and restart readiness
If the engine has been automatically stopped by the Auto Start Stop function and it is possible to start the engine automatically, the light indicator on the instrument cluster lights up green.

Engine is not ready to stop or restart
If it is not possible to stop the engine automatically or it is not possible to restart the engine after the engine has been stopped automatically, the light indicator on the instrument cluster lights up yellow when the vehicle is stationary.

The Auto Start Stop system has detected that:

1. at least one prerequisite for the auto engine stop is not met
   – or –
2. at least one exceptional condition for the Auto Start Stop function is met.

1. Please see chapter "Prerequisites for the auto engine stop" on page 63.
2. Please see chapter "Exceptional conditions for the Auto Start Stop function" on page 64.

Responding to warning symbols
If there is a fault, a message will appear on the instrument cluster to indicate that Start Stop mode is deactivated.

• Have the fault repaired by an authorized Porsche dealer. Porsche recommends an authorized Porsche dealer, as they have trained technicians and the necessary parts and tools.

 

I wish I would disable *** permanently. I plan to ask about this at the next service, soon.

I've been almost T-boned twice now as the car's engine literally stops while I am still moving slightly waiting for a gap in the traffic to pull into. It is very unnerving to have the car quit on you just as you press the gas.

I could see it if the car stops while you are actually at a complete stop, but this software apparently stops the engine WHILE YOU ARE STILL MOVING. I am at a loss to understand how that's a good design. Grrr...

 

The Auto Stop/Start can be turned off, correct? I always turn it off in my BMW, but if you cannot turn it off in the Cayenne, that may be enough to keep me from purchasing one.

 

T-design9.com makes an auto start stop memory module for the older Cayennes, but they don’t have one for the new ones yet. They claim to be working on it but they are pretty unresponsive when I ping them for any sort of ETA, so who knows.

Here is the older one: https://t-design9.com/memory_module.html

 

So there isn't a button in the vehicle that can disable this? My '17 Audi S6 had one, and my '18 BMW has one as well. I am looking at the E Hybrid, so maybe it wouldn't be as big of an issue as the electric motor should stay on.

 

You can navigate to a screen in the PCM to turn it off, but it gets re-enabled every time to start the car.

You can supposedly set the customizable diamond button to be the auto SS on/off button (I haven't tried it yet).

 

You can set it the diamond button to shut it off or you can program the individual button.