Yesterday, I was backing my car out of my garage when all of a sudden, I got an error message "reversing not possible." I tried switching into drive then back into reverse, and this time, it would not even go into reverse at all. Halfway down my driveway, I managed to put it into drive and did a hard right turn to get down the rest of the way to the street level, as we have a decline out the garage (thankfully not scraping the car). I looked for a place to park it where I would not have to reverse back out of a spot and managed to park down the street from my house. I turned off the engine, then turned it back on, and it still had the error message and would not go into reverse. I had been on my way to my mom's house with some groceries for her so I walked back home to put the groceries into the fridge and called the local dealership (thankfully only about a mile away from my house). I was able to get an appointment right away and by the time I walked back to my car to drive there, the reverse was working again. I drove to the dealer, parked the car and then tried to reverse again, it worked again.

I told the service advisor what happened and he said the transmission is part electric, part mechanical. He thought that it was an electrical issue as it did work on subsequent attempts. I told him I had only made one car payment on this car so far, having not even gotten my license plates yet. He then (jokingly?) said, don't expect to own this car for very long without getting to know me. Uhhh, thanks?

So I dropped it off at 9am yesterday morning and he called in the afternoon to say they had no idea what was wrong with it, and they were sending a message to a headquarters to see if it was a known problem to figure out how to fix it so they kept it overnight and I hope to hear back from him today. I Googled it and it appears a lot of GLAs have had a similar problem, and I also saw someone else that had to have their transmission completely replaced after a similar issue. Despite being a 2017, my car only has 6700 miles on it. I knew going back to Mercedes would be expensive, and I'm really grateful I bought the extra two years on top of the CPO one year on my car, but wow, I didn't expect problems so fast.

I suppose it could have just been a weird grimlin one time issue (like the time I got the warning error that the distronic plus was inoperative - which never came on again, or the tire pressure indicator lights all coming on on the drive home from the dealership). Still, I can't help but be nervous that I may have just invested in a very costly owning experience.

Has anyone out there ever had this issue re: the reverse not working in their SL?

 

In another thread here I mentioned that my nearly new 2020 S560, with only 3,800 miles now, downshifts roughly. Left it at Fletcher Jones for two weeks and they could not fix it. MB directed them to replace the transmission and torque converter, which they did. The car now shifts worse. MB is offering to buy the car back. WHY? Why can they not trace the problem, to some computer or other piece of equipment responsible and simply replace that component?

The R231 SL’s have been rock solid. I do not recall anyone here complaining about transmission issues. I hope the OP’s car wasn’t traded in with so few miles for a reason other than the previous owner wanted something new.

 

One thing I have noticed about the R231 is the lower shifter area is like a funnel for dirt, dust, liquids, and whatever the detailers spray in the car. Theres no where for **** to go but down into the electronics. First place I would look would be that area and it's history carefully.
I'm guessing that would throw a code too. Seems as though your transmission was having trouble shifting right?

 

Our SL550 is a 2014 with 49,000 miles. We've never experienced this or any other mechanical issues. The only repairs have wear items like brakes and a couple headlight bulbs. Hope they get it diagnosed and sorted out for you.

 

With them mention electrical it makes me wonder if the systems battery in your car is the original. Four years old with low mileage wouldn't be excessive if the battery was kept on a battery tender when not in use for long periods. It may be worth a try to have the trunk battery put under a load and see if it is getting weak.

 

Thank you all for your input. It is so frustrating. They kept the car for two full days and then called me to say they can't replicate the error or figure out what caused it, so I needed to just come and get it. I told the service tech (who I otherwise like very much) that I was scared it would happen again and he just told me to take a picture of the error code if it does. I'm thinking a video would be better as it would prove that the car would not shift into reverse at all - putting the gear shifter in reverse it would not stay and would only let me use drive, neutral or park. So incredibly frustrating!! To make matters even worse, I got there right before they closed to pick up the car only to discover they had parked it outside for those two days (it is a garaged vehicle) so it was covered in dust and pollen and they had not washed it. They also added two nice black scuff marks on my beige carpet for me. I know I can wash the car myself and Chemical Guys cleaner will get the scuff marks out when I do, but I have to admit it was just the cherry on top for me. This is the second bad experience (out of two) at this dealer - my mom had a horrible time with her SL with them - they also did not wash her car before delivery. They also have no cashier, and only allow you to check out with your service advisor, so if he or she is busy, tough luck. I hate using them but they are a mile from my house. Still, if it happens again, I'm tempted to drive to Fletcher Jones (where I bought the car) to service it, or South Bay, where our experiences have been generally good with prior Benzes.

So I guess good news is that the error has not reappeared so it was not mechanical (as my service advisor pointed out). The flip side of that is that if it is electrical, it has not been fixed. Sigh. I still love the car itself but owning it has not been easy (for the whopping two months I've had it). I'll check the shifter area and battery if it happens again, thanks for the advice. And yep Streamliner, the worrier in me did think, was this why the original owner got rid of it? Hope your 2020 is sorted out - I have to admit, if Fletcher offered to buy this one back, I would sell it for the peace of mind if it were me. In your shoes, I'd probably do the same.

 

I will pay money a dealer not to wash the cars; they do a terrible job anyway. Our procedure for bringing in a car to the dealer is to replace light floor mats with rubber mats (always got those for free from the dealer when buying the cars) and then tape of the door sills with masking tape. They have a tendency to scratch those with one visit.
Then I require them to place a seat and steering wheel cover on while I am there. Then they place do not wash stickers inside the car.

While your issue appears to be a dramatic sounding error, it likely is just the battery or switch (shift selector) related and easily remedied. Never heard of the error in this forum either so it is a rarity. They wouldn't buy back the car because if is technically minor issue. Please video the incident if it happens again and then make then switch batteries and maybe the shifter. Neither is expensive and they will do that easily.

I don't think the car was traded for that. More likely this happens from the car sitting around undriven which takes a toll on the batteries. Once a battery fully drains, they can become damaged and must be replaced...

 

Thanks Wolfman for the advice...and on the buyback, I was more just responding to Streamliner saying Fletcher would buy his back. I know they never would mine for this, but admittedly I'm a worrier, so if in some Twilight Zone offered, I would say yes. And then promptly go buy another SL.

 

I would consider getting a battery tender and use it when the car is sitting. You don't need anything crazy expensive. I use a Deltran battery tender plus, 1.25 amp 12V. It can be used on flooded or lithium batteries and keep the battery at optimum level. Your MB dealer can hook the pigtail up to the battery in the trunk and pull the end with the plug up so you can easily hook up and disconnect. I can't say for sure the battery caused your issue. However, having the tender in use when the car is idle will save you replacing an accessory battery prematurely. It will also save youthe potential problems with computers if it does go completely dead. The Deltran can be picked up for around $50-60 dollars here in my area. Walmart and tons of other vendors carry them.

 

Wahinee,

Sunbelt golfer has good idea.....What I did was:
1)Bought the MB battery tender from the MB parts Dept
2)Wired the power connector in the trunk (it is at the rear passenger side of the trunk) to the main battery in the trunk.....MB dealer can do this for you if you can not.
3)I leave the tender connected to the outlet in the trunk and when in the garage just run a small extension under the rubber seal at forward side of trunk lip to an outlet in the garage,
My car is a 2018 bought late 2017 now with 17,000 miles on it (mainly summer use, sits in heated garage in winter). No issues at all with either the main trunk battery or the accessory battery behind the passenger seat....both batteries show to be in great condition using this method.

Maybe your usage is such that the battery hasn't received a full charge or was stored B4 you bought the car for a long time and was totally drained down so it went into reversal and the battery is damaged.

I'd say what has been said already as possible causes is probably correct.

What I would do:
1)Use another dealer !!! My dealer is great....Without prompt covers seat/steer wheel, NC washes as often as I want on both cars I bought from them and prompt service with always a loaner and personal attention ....so.......some dealers can be great and maybe time to cultivate a new one explaining why you coming to them.....cultivate a relationship with not just the "order writer" but, the "Service Mgr, Sls Mgr and GM ...ALSO the Hd Mechanic and you will be taken care of.
2)Have the new dealer check the battery....if on the way out get a new battery...my experience is if a battery tender not used battery will last 4 yrs but, if a tender used will last a lot longer......I have a 1986 560SL bought new with now 30K miles and although always in heated and A/C garage when I didn't use a battery tender I'd need to replace the battery about every 4 yrs.....now that I am using a battery tender on that car same battery in place for 8 yrs and still perfect !
3)Get and use a battery tender and use when car not in use.

PS: In 25+ yrs of various MB sedans and SLs I have never had a major mech or Elex issue. Remember you are under factory warranty (just make sure if you intend to keep the SL like I plan to get an extended MB warranty so things that might happen will be covered once you are out of whatever coverage you got when you bought the car.

If you do all above you will be fine.....biggest hurdle is finding a good dealership !!!

Let us know how things progress.

BTW>>>>Glad you had the sound system upgraded.....for me makes a world of difference to get a surround sound feel.

One more thought.....Wolfman is correct Re Dealers...actually anyone scratching up the polished sil plates....What I did and some others here is to have anyone dealing in "wrap" to cover them with a "carbon fiber" wrap.....looks lot better than the polished finish AND easily re-done if get's messed up......The plates just pull off easily covered in the wrap and reinstalled.

Steve

 

Maybe I'm confused but why not use the installed battery connection posts under the hood for the main battery? I also have an installed pigtail for the AGM battery behind the passenger seat. I use a CTEK maintainer on each one whenever the car is parked for more than about a week. Both batteries stay fully charged.

 

Response to rmorin49

My hook up easier for me as I just leave the batt tender in the trunk connected as described .....no need to unhook from underhood batt posts and store the tender

FWIW the Chief Mech @ my Dealer thought neat to use the trunk power connection wired to the trunk battery as it is a permanent hook up as described and told me it is the preferred way and location to use a battery tender.

Different strokes.....as they say

PS: As I understand (from the Chief Mech @ my Dealership) no real need to charge the aux batt as it draws very little when car not in use and will charge up once engine charging system in operation.
Think I have also read somewhere (can't find it now or maybe it was the Dealer Chief Mech) who said that the main battery would charge the aux battery if it fell below a threshold but, this would not be the case if a tender was connected to the underwood jumper posts.

Be great to have a full Alex schematic of the main and aux circuits as well as full explanation

 

See my posts above BUT, better yet see here below:

Hello Steve!
The positive side of the battery is wired directly to the positive terminal under the hood. The chassis ground is the variable. Its connected through a battery sensor B95.
I would suggest to clamp directly onto the battery itself. The eco start stop battery is not wired directly to the jump start terminals and is only charged by the SAM as needed.
Happy Holidays!
Mark Lipizzi
Master Certified Shop Foreman
/////AMG Brand Ambassador

 

I'm curious to know if the issue has resurfaced, or if a solution was found.

 

Nope, they never figured out what caused it and it never happened again. I still keep backing into every parking space that I can though just out of being gun shy. But I guess it was a random gremlin error. If it ever does happen again though I will be sure to film it with my phone for my service advisor.

 

Strange, but hopefully just a one time quirk.