cdog533

This explanation matches the symptoms perfectly, as the issue seemed to occur most during high-load, high-gear, low-rpm situations.

I'll have to chat with my local service manager about the fix.

Snipe656

Actually on Macan forums are a number of posts about people having their cars go into a low power mode. I found those posts around a year ago when the problem started up on my Cayenne. The driving symptoms the people were describing were very similar to what I was experiencing with one key difference being in the Macan they got a message on their display saying something like low power mode but safe to drive. It was fixed with software long before I found the posts.

Now the Panamera briefly having a version of this engine I never could find posts about it having the issue, but really could not find too many posts from owners of those cars period.

rdboxster

Had the software updates installed today. The dealer never questioned the issue. He asked right up front was the loss of power while using cruise control which it was. An hour later I was on my way. Have to say initial drive the acceleration was much smoother and overall feel was better. Need to have more time before any conclusions. The loss of power hadn't happened for some time since we live in flat country. The Service writer did mention some thing about false cylinder 3 misfire error setting off the knock detector.

Snipe656

Something I have noticed after the update is my fuel economy has picked up. I always thought it was odd I saw no difference in fuel economy from my original engine that had the no boost problem all the time to going to a replacement engine which never exhibited boost being backed out. My best tank was 19 mpg just once then a number of 18s yet many tanks were all freeway driving. Not yet taken it on an all freeway drive but noticed on a few 40-60 mile all freeway drives the computer saying 24.x mpg which it definitely never did before.

cdog533

That is much higher than mine...

My average fuel economy is 15.8 mpg. I drive about 70-100 miles per day, 80% highway.

rdboxster

Mileage has been good for this car. Over the past 3000 miles about 21. Yesterday we put on 120 miles mostly rural 4 lane and interstate. Average speed according to computer was 63 with 23 mph. I have verify the computer has good accuracy. Been very pleased with the mileage. Hopefully there isn't a negative affect with the code.

Snipe656

I have logged every drop of fuel I have put into this thing. I tend to drive 50-60 miles a day. Average over almost 20k miles has been 14.9, best that one time 19, last was 16.9 which most of that tank had the software update already applied. I speed by a fair amount and do not drive like a grand mother by any means. I honestly do not care about mpg but since I track things for my business log it makes me very aware of what I am getting.

Through all those I had many all freeway trips, a few even at the speed limit or no more than 5 over the limit, most of those were 17 to 18 mpg. My wife might take it to San Antonio and back this week, she drives like a grand mother but has used the SUV for that trip before and still not even got 19 out of it. Will be interesting to see if perhaps it does much better for her this time around.

TxHoon

Sadly, my new to me GTS is exhibiting these same symptoms. I drove from Houston to Lafayette and while driving through town, I noticed the lack of power while trying to accelerate. The boost gauge confirmed it.

After the engine has a chance to get hot for an extended period it does not want to build any boost unless I floor it.

Nov 15 build date.

Can an anyone confirm the fix? This is a CPO I have had less than a week. I almost want to ask for my diesel back.

rdboxster

I would suggest going to your dealer and have them install the fix identified in this thread. Until it's proven otherwise I would say Porsche has found the cause and provided the solution. My dealer was on top of this and it took about an hour. Just the right amount of time to have coffee and walk through the show room.

TxHoon

Thanks for the reply. I already spoke to the service writer and sent him a video I made showing the no boost, and also sent him the updated DME number and info. He spoke to the service manager and he was also aware of the fix.

I am going in on Monday to have it reflashed and have a key added to the car. It was only delivered with one.

I will update after my next road trip which should be end of next week if not sooner.

stiles_s

one more data point. I have had the fix applied and finally got a good road trip done over the weekend to test. Good news is that I wasn't able to repro symptoms. Cautiously optimistic that it is fixed.

wkearney99

I called my dealer this morning and was informed there's nothing out for my VIN. I've had mixed feelings when speaking with this particular service manager, so I'm not sure as to whether this is accurate or not.

I don't want to waste my time (again) trying to describe/demonstrate that which I cannot reliably repeat.

I checked the VIN on the Porsche website and no recalls are listed for it. But I gather this isn't a recall, correct?

TxHoon

It is not a recall. It is an update. The issue is most people do not drive far enough to have the engine fully hot and have the "heat soak" issue, so most people are not aware of how the car responds when hot. I didn't notice mine until I was 4 hours into an 8 hour drive.

I went and had mine updated today. We will see how it goes. Good luck!

rdboxster

I have put on over 300 miles since the update. Includes city, rural highway and interstate. Normal acceleration is much smoother and more in line with what I would expect. Been no indication of boost loss at any time. I did a blast from 0 to 100 mph on a country road that was very smooth. I know this was for the loss of boost so maybe a reset occurred during the install clearing out the ECU but regardless the overall result so far has been great.

wkearney99

Headed to the dealer this AM. Talked with Porsche USA just now and they don't show anything related to my VIN. But the rep on the phone 'had heard of' the cruise control issue, but did not have resources at her disposal to confirm/deny that was relevant to my particular vehicle.

If this were repeatable I'd gladly do whatever it takes to demonstrate it, but it's random and infrequent... but often enough to be repeatedly annoying.