Ron.s

DAP-I seem to have an issue with my Distronic…has anyone else experienced this? All of my electronics were updated a few weeks ago in an attempt to cure a few random problems.
Primary issue was my set speed was changed (not always) along with acceleration or braking when a traffic sign was misread. In Assistance, I had turned off Traffic Sign Assist & Route Based Speed Assist. Example of issue-My car was misreading 80mph as 60 & braking aggressively. I may be missing a new setting somewhere, haven’t had time to go through all of the other settings, just “Assistance”. My 2020 GLE misread signs less often and did not change the speed setting.
After all the updates I no longer have a setting for Route Based Speed Assist and my car now adjusts set speed to every misread traffic sign. For example I had my speed set at 85 and the car read a sign as 70, changed the 85 to 70, and started braking. In Idaho there are stacked signs-the upper one reads 80 and below “Trucks 70” so this happened about 50% of the time. In heavy traffic this could be a safety issue for some people.

TOWING-Another unusual event. Once a year I tow my UTV to a second home in the Fall and back in Spring. The total weight is a little over 3500 lbs. As I started out yesterday I was cussing myself for not getting the V8 with more Torque. Driving at about 80-85 on the Freeway I averaged 10.1 mpg for 130 miles and had to make an extra gas stop. Looking at an idle Wind Farm and a few flags there appeared to be a gentle tailwind…weather forecast said 5 mph. The rest of my trip was on 2 lane roads through Nevada. I had lots of power but it felt like I had a strong headwind or no Torque…mostly running 8th gear & 7 on hills. Paddle shifted to 9 on some flat ground but not much improvement in mpg. I set my left gauge to monitor the AMG feature of degree of incline and body roll (axial rotation) so that I could track mpg on flat ground. I also monitored the Boost from time to time, looked strong.

​​​​​​BIG SURPRISE-About 380 miles into my trip (8500 on the Odometer) I stopped for gas (the 3rd time) and reset my gauges. I wasn’t monitoring gauges now but soon noticed that the car felt more like I didn’t have a trailer attached, loafing along with ease. My first thought was that I had a nice tailwind but there was almost no wind at all and later a slight headwind or sidewind depending on the direction of travel. As near as I could estimate my economy improved 20-25% for the last 250 miles of my trip. I can’t compare the overall mileage because of all the elevation changes that differ along the way but did my estimate using stretches of level ground. All of a sudden my towing concerns went away.
I’m still scratching my head about what happened. Could there be a program to limit performance towing until a certain mileage? Did the TCU or ECU get reset by my Dealer and go through a learn mode (not noted on the work order)? Is this nice surprise going to continue or revert back next trip?

SIDEBAR-The Dynamic Plus Package is worth every $. I’m towing without trailer brakes and no Equalizer hitch…marginal at the weight of 3500 lbs. There is no understeer on corners at speed that one might expect with a short wheel base SUV that’s not a lot heavier than the trailer. The active sway bars keep the car flat instantly, no delay. The gauges measured at least 6 degrees of side to side sway adjustment if I understand the reading. When a corner has no camber my gauges read as much as 5-6 degrees and on some sharper ones I wasn’t comfortable taking a peek. The gauges measure a degree or two sitting on a slant but the faster you take a corner the higher degree reading so it almost has to estimate the body roll adjustment in the calculation. (Need to read my AMG info)
Thoughts anyone?

mikapen

Interesting reports. I have a couple of thoughts, although they are both unlikely.
First - did you get some contaminated gas? Unlikely, but it might explain some de-rating that your engine experienced. (Was your gas cap tight?)

Second - transmission temperatures. My AMG53 (with 8,500 miles at the time) experienced some high tranny temps at the track, on a particularly hot day. Air temperature hit 101F and I had my right side display set to show RPM plus tire pressure/temp, along with Tranny and Coolant temp.
After lapping for about 10 miles I experienced short shifting (5,000 rpm instead of 6,500rpm) (in automatic AMG Plus mode - nice performance) and a power loss, and observed the transmission temp had reached 276F, pretty hot. A cool down lap saw the tranny temp quickly decline (less than a minute) to 205F, and performance return. I called it a day since I was also eating tires.

I haven't towed with the AMG53, but when towing our 27' RV with the previous ML diesels, I stayed below 70mph, since mileage fell off rapidly above that speed. Went from 15mpg at 60 to 11mpg at 70.
I also find that higher speeds (75+) the AMG53 (not towing yet) eats more fuel than at 60, so I think there must be a lot of wind and or rolling resistance from those fat MO-1 tires. The '20 GLE450 didn't have that mph penalty, but it may also be that the supercharger seems a lot more aggressive than the 450 turbo alone.

Anyway, I wonder if you didn't put more heat into the transmission (or system in general) trailering at at 85mph, and got de-rated. Maybe find that transmission temp display and watch it, although it'll be next Spring before you are pulling again.

Ron.s

Thanks Mike, I’m sure it wasn’t fuel related. I took about a 100 mile trip the week before and noticed a similar lack of torque cruising and what seemed like poor consumption for the distance but didn’t make any calculations. In total there were 4 different refueling sources….Costco twice, Luvs Truck Stop, Chevron…all high volume sources. It’s hard to explain, but a lot of times when cruising at a constant speed, I felt like the car was struggling a bit. When I needed power to pass or climb a grade it was there. There is a stretch before one town of over 20 miles where the max speed is 65. I was still only getting maybe 11-12 mpg and couldn’t pull 9th gear for long.
Actually I worked the car harder on the last leg of the trip with two long steep climbs of 2000-3000’ elevation changes. I have made the trip with my 6.2 liter GM truck (420hp/460TQ), my wife’s 3.0 Audi V6 and my 2020 GLE 450 for comparison.
I'm inclined to think that something changed with the ECU map but that doesn’t seem plausible. It’s remotely possible that Luv’s got a dump of Non Ethanol fuel by accident but doubt that adding a half of tank would change anything.
The best feature is still the handling, always consistent and always exceeds my expectations. The better brakes are also a noticeable improvement while towing. My wife even commented on how it seemed like we were going much slower than the Speedo indicated. She isn’t bashful if I get past her comfort zone.

Swordfish99

I have definitely had the DAP issue, multiple times. I find this a very dangerous event as it always happens during highway speed with people behind me. My car goes in this week for winter wheel change over and this issue is on my list to question how I turn this off.

Ron.s

At this point I’m not optimistic that there is any fix. My very experienced Shop Foreman communicated directly with MB support and they suggested updating all of my systems to the latest software. Since that didn’t work I’ll report back. It’s one of those things that isn’t easy to duplicate by the Dealer…one of the ways MB can dodge the issue…so I’ll probably need to make a video,
I formally filed this issue with the NHTSA.

Ron.s

I scheduled my 10k A Service yesterday, listed a couple of these glitches, and was told by the scheduler that there is a recent “open campaign” for MBUX that addresses this set speed issue. I’m not sure I trust this source completely but I challenged him on specifics. My appointment is a few weeks out so let us know if you get this update and what it covers.