zibby43

Especially with how heavily incentivized leasing has become (which cuts both ways; I love this because I only drive 7,500 miles a year - maximum).

Will update the thread tomorrow after I speak with the dealer. Hopefully it'll be of some services down the road for anyone experiencing similar issues.

cjaredscott

Here's what the print-out was on the RO.

"Client States that the vehicle does not seem to have as much power as it used to, please check and advise
Cause: software.
Check individual parts of traction and brake system for fault code. Program and code control unit.

Description: Verified concern. Wheel speed sensor faults in power train module and communication with traction control stored in AMG Drive Module. Performed guided diagnosis for faults. Result was to perform diagnosis via electronic stability control module. Checked stability control module. Fault P0606E9 internal control module error fault is stored. Performed guided diagnosis Performed software update to electronic stability control."

This car seems to not have issues anymore. Knock on wood.

And I know you know this, but just to say it again, some dealers are terrible and don't care in service (when it's warranty), and some will go the extra mile. I've experienced this way too many times. I'm not sure what region you're in, but I have one that is good (so far), 1 that is awesome (so far, knock on wood) and 1 that is absolutely terrible. It was a lot of trial and error for me.

c43PDX

very interesting, so stability control was kicking in or faulty thus causing power loss, which makes sense.
I'd say dealerships take care of their clients that drop $$ there. Just like performance shops, you need to make street cred and relationships over time.
I wouldn't treat my customers like ****, but the ones I enjoy personally or drops $$, usually gets better treatment, human nature.
Especially in a high volume business, they are only one to you, but you are many to them.
"I paid like everyone else, and I should get the same treatment as the guy that just bought an AMG GT with 40k dealer markup!" nope.

Glad your problem is possibly sorted out, and such a unique issue.

cjaredscott

Yes, evidently it was dialing the power back, but was faulty even to the point that the stability light did not come on when doing so. And yes, that is typically the case, regardless of what people think of it.

zibby43

Cannot thank you enough for posting this.

This is exactly what my car feels like - like it’s getting bogged down and not producing full power. It’s very similar to ESP cutting in, but I never get the light.

Will pass this on to my dealer, who was supposed to call and reschedule me today, but didn’t.

cjaredscott

Of course, I'm happy to try to help. Hopefully this is the issue and it actually does help them remedy the issues with your vehicle. From your description, it sounds as though it could be.

zibby43

Dealer contacted me and said they'll need the shop foreman to ride along with me before taking it back into the shop.

I'm fine with that, but it smacks of "we don't believe you." Going to be a satisfying drive. They also said a loaner car wouldn't be available until October 1.

So I'm going to be stuck making a payment for a performance-oriented car that I was without for a week, and will now be forced to drive down on power until the 1st. That doesn't seem right. If it was a badge falling off, or some other small part needing replaced that didn't derive the car of its chief purpose, I wouldn't mind.

But is it crazy to be upset with what has transpired thus far? Or am I expecting too much?

cjaredscott

Yeah, in your case it definitely sounds like that, since you've provided very clear instructions on how to replicate.

Are you on a lease? I've had MB credit payments for me in situations like these.

I think your dealer may be the culprit. Unfortunately, some are just really bad and do not care about fixing the car unless it is easy or the customer is paying.

zibby43

Yep, it’s a lease. Very useful to know about the payment credit. If they find the fault, but can’t get the car in until October 1, I’ll be patient so long as they credit me for being deprived of the car’s purpose for a month.

And you’re right about the dealer. They used to be fantastic. And I had a magnificent SA that, anytime I had an issue, would say “Bring it in whenever you want.” Would always have a loaner, etc.

He was an enthusiast, and recognized the fact that I was as well. On top of recognizing the fact that all told, my family has had about 30 Mercedes Benz vehicles over the past few decades.

Now I’m playing musical chairs with SAs.

cjaredscott

That's unfortunate. Definitely go for the credit. Call MB if you need to, if the dealer will not help with the credit. I've had a very similar experience before, and luckily it seems (again, knock on wood) that I've found a great dealer. I hope you can either find a SA who takes care of you at the dealer, or a dealer who will take care of you.

zibby43

Car is fixed! I’ll give the full write-up later.

Thanks again for all your assistance!

cjaredscott

Awesome! Can't wait to hear what happened.

C43HeartBoost

Awesome, very glad to hear. I have been following since chiming in early on.

zibby43

Thanks again to both of you for all of your input along the way. Unquestionably helped me get the car squared away in a timely manner.

Below is the recap:

All of the "Starter Battery Critical" and "Starter Battery Partly Charged" warnings I was getting nearly every 2 weeks since taking delivery in late February were definitely a warning sign that my battery was faulty. For several months, I mistakenly assumed that the battery warnings were a result of my limited driving (due to the pandemic). I only once achieved "Starter Battery Charged" status, and that was only for a day or so.

A few weeks ago, my Mercedes Me app started acting really bizarre, and reported all sorts of weird readings, including indicating my engine was in the "On" position, even when the car was off and locked. Even made a thread about it. All battery related.

The battery problems also triggered a low voltage code (not visible to me; no CELs or anything else): "CONNECTED BATTERY MAINTAINER AND SDS AND QUICK TEST. AMG DRIVE UNIT CONTROL UNIT HAD FAULT CODE U012287."

They had to remove carpeting and panels on both the driver and passenger sides of the car to find the control unit, disconnect it, and try to eliminate the code. Then the PTSS case was started: "TELEDIAGNOSIS DATA FOR THE FAULT CODE WAS CAUSED BY VEHICLE BATTERY BEING LOW. WAS TOLD PER PTSS TO DISCONNECT AND RECONNECT THE ESP AND AMG DRIVE CONTROL UNITS. RECHECKED FAULT CODE. FAULT CODE WAS NO LONGER PRESENT."

So when I got the car back, after all this, I still couldn't get the power to exceed 250 or 260 horsepower when matting the accelerator in Comfort mode. Bear in mind, I'm in the break-in for this car still, at around 740 miles.

When I took the car back today for a test drive with the shop foreman (who is outstanding), he was watching my RPMs and the HP readout when I was accelerating. He noticed that the car was short-shifting at like 4,500. When I dropped into 5th gear manually on the highway and did a modest pull, I easily reached the 370 horsepower level.

So, eliminating the low voltage code DID restore power. For whatever reason, the car is really reticent to hang onto gears in C, which is what continued the perception that I was still lacking power. This behavior from the transmission is unlike anything I ever experienced in my '18.

Which leads me to the next question: I know that some of the newer AMGs have Launch Control/Race Start disabled during the break-in period (first 1000 miles), is there some kind of software programming going on in the background that is causing the car to shift around 4,500 when I'm still under 1k miles?

jhpmbusa

i am in the same boat with you, I now only have 387 miles after owning the car for over a month. As i am driving a lot less and mostly on local roads and respecting the 1,000 mile break in period - i feel like the car is learning that i drive like a grandma lol. If i don't push down on the pedal, i feel like it doesn't really react. I am thinking its a learned behavior from the car's perspective. Unfortunately, I got the starter battery message as well last night for the first time - it mentioned i should drive it around for at least 30 minutes.

19’43s

Guys find a way to drop the cars off the the dealership and don’t take them back if issues aren’t fixed that’s what usually gets things done w mbusa or Canada lmfao been there done that guys there no being nice w these *******s so you gotta be one back to them they love being abused and yelled at like a dirty **** 😂😂 but all jokes aside fr don’t take them back and demand for new cars honestly no one drives **** treatment after buying brand new benz especially a ****ing amg idc if it’s hand built or not it’s a amg, amg started off by tuning benz cars so anyone that says it’s not a amg you clearly don’t know your history.

alexasa

iTrader: (1)

there is no break in period. boy who cried wolf syndrome on this one - no reason dealers become so reluctant to entertain issues.

zibby43

Yawn.

Same code as experienced by others initially: https://mbworld.org/articles/mercede...oss-explained/

Which is why a PTSS case was opened to clear the code.

Car was experiencing same behavior afterward, whether through learned behavior or something else, except this time, it would reach max power outside C when doing 5th gear manual pulls. So power was clearly restored.

There’s a break-in sticker on the top left corner of the windshield. Whether or not you philosophically believe in it is one thing, but the shop foreman recommended following it. Especially varying the gears and rpms.

zibby43

If it charges fully after that 30-minute drive, you should be fine as far as the battery is concerned.

zibby43

After hitting the 370 hp mark by doing a 5th gear highway pull in M, I thought everything was normal.

Since I'm close to 800 miles, I wanted to let the car rip a little in S+ today. Did a variety of pulls, including from a dead stop in 1st, and rolling pulls in 2nd, 3rd, 4th, and 5th gear (used the kick-down for all of these rolling pulls).

Using the automatic mode (S+), the maximum readout I was able to achieve was 324 horsepower. The only time the car felt as fast, if not faster, than my old 2018 car, was during that 5th gear manual pull to about 5.5k rpm on the highway the day I rode with the shop foreman.

In C, S, and S+, 99% I can't get past 300 horsepower, whether I use the kick-down or not, and the car just doesn't keep me pinned in the seat.

Furthermore, sometimes when I start the car, the exhaust is louder on startup and idle with the PE off, as opposed to PE on. If I switch to PE on, it gets quieter. If I then switch the PE off, it gets quieter still. And finally, after performing this sequence and turning the PE back to the "ON" position, the car gets louder again.

On the plus side, the battery does hold a charge now.

cjaredscott

That is unfortunate. I guess they need to explore other possibilities, then. Just to confirm re: exhaust, the car is already warm when you're starting it?

Maybe try to get it past 1,000 miles incase it is in fact the computers doing something for the break-in period and the dealers just don't know about it?

Also, this may sound silly, but open your hood and make sure the intake is all on right -- I had that happen once years ago -- MB didn't put it back on properly, and performance suffered.

zibby43

Thanks for the reply. Good question. I've noticed this behavior during both cold and warm starts.

I've been doing tons of research/reading, and now that the battery problem has been sorted, what I'm experiencing most resembles what is described in this thread: https://mbworld.org/forums/c450-c43-...-accuracy.html

They did check for boost leaks in addition to changing out my battery, but I don't know if they checked all the other connections, including intercooler and exhaust valves (seized exhaust valve was the culprit in the thread above). Or, like you said, the car is mechanically fine, but something is happening in the automatic modes that is making it short-shift no matter what I do. It's crazy how hard I have to beat on the car to crack 300. It's also crazy to me how little difference I perceive between C and S+. S feels virtually identical to comfort. In S, moderate throttle application has the car shifting at like 2k and it just runs through the first 3 gears like I'm feathering the throttle.

I've had all sorts of tuned BMWs (N54 motor, N55 motor), so I know I have a pretty good butt dyno (perceiving all the gains I made as I gradually increased power when tuning those platforms). And what led me down this rabbit hole in the first place was noticing how much faster both the '19 E450 and '20 C300 I recently drove felt, in comparison to my C43.

Just remembering how my '18 C43 felt, as well. It would really hang onto gears and hold revs in S+, and I had no trouble hitting the max HP values. It felt devastatingly fast from a dig, too. Just as fast as my old W204. My '20 just isn't close. Only time I've come close to replicating the feeling on my '20 was with the 5th gear manual pull.

cjaredscott

Interesting. After reviewing that forum, and the linked forum, perhaps your issue is also with the PE. If you don't mind my asking, what metro area are you in?

zibby43

PM inbound.

zibby43

Was told by SA that they recommend I continue to drive the car until I pass the break-in threshold of 1000 miles, before bringing it in to investigate the power loss further.

Which suggests 1 of 3 things: 1) The short-shifting in the automatic modes is some kind of software that keeps the revs down until the break-in period is achieved (I find that unlikely, as I haven't seen any information that would confirm this); 2) They just want the break-in to be over before they continue beating on it in the shop, replicating my problem; 3) They are punting on 3rd down.