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2019 S560 M176 engine code
These are pics of the flaps inside the tailpipes. Notice the one that is partially opened. That one should be fully closed like the other pic. You can see these by shining a flashlight inside the outer pipes on each side.
This is either a stuck flap which has to be worked loose and lubricated or a broken spring/bad actuator. This is my only active code stored. No tune install until this is fixed. The stuck flap on RH side of vehicle - should be fully closed with vehicle off LH exhaust - flap closed properly engine off
You should just leave them open via coding or module.
I knew someone was going to say that.
They have to be working freely with working actuators first to be coded to stay open.
The tune I bought will handle the flaps and command them to stay open.
I sprayed a little lube on the inside of the pipe as mine were making a lot of noise when I turned off or started the car. Sounded like a barn door closing. That was a couple weeks ago and they still seem quiet so I guess it worked. For how long I don’t know.
I knew someone was going to say that.
They have to be working freely with working actuators first to be coded to stay open.
The tune I bought will handle the flaps and command them to stay open.
ok, lube up the sides and push it open with a long screwdriver, or take off the actuators (on the sides) and be done with flaps 100%
My extended warranty should cover the bad actuator. I had to wait 30 days until I could use the warranty then wait for a spot at the Mercedes dealership service department for an appointment. I'm at 60 days of ownership now. On the 24th it should be fixed right and I'll have no more issues with it.
Hopefully the extended warranty will cover it. I gave up on my extended warranty seems like these days it covers next to nothing unfortunately. I sprayed the lube right inside the exhaust and hit up both sides of the flap. It seemed to work.
My extended warranty should cover the bad actuator. I had to wait 30 days until I could use the warranty then wait for a spot at the Mercedes dealership service department for an appointment. I'm at 60 days of ownership now. On the 24th it should be fixed right and I'll have no more issues with it.
Most likely the Extended Warranty will not cover the repair as they didn't on my car. They did try to fix via the original warranty but the issue reappeared. I repaired it myself.
After spending most of the day trying to fix the flaps myself I have decided to let Mercedes handle it. The flaps are moving easily now after lubricating and freeing both of them up but the actuator springs WILL NOT LOCK ONTO THE FLAPS CORRECTLY!!!!!!!!!!!!!! I'm so pissed off right now. I command them to move and I can hear the actuators but the flaps don't move. Springs aren't broken. I've looked in my WIS/ASRA and there is no procedure to replace the actuators (that's another story - how hard it is to find anything in Mercedes Service Manuals). I've tried everything from holding it loosely while commanding the change to mounting it tightly and letting the spring fall into the grooves itself and also setting the flap halfway and trying to get the spring to catch it as it turns. Nothing works. The actuators work fine when dangling on the harness disconnected from the flaps. I don't know how these techs at Mercedes make any money. Everything is so unbelievably hard to work on. I guess that's why it's $250 an hour. It's worth it.
I need a drink!
After spending most of the day trying to fix the flaps myself I have decided to let Mercedes handle it. The flaps are moving easily now after lubricating and freeing both of them up but the actuator springs WILL NOT LOCK ONTO THE FLAPS CORRECTLY!!!!!!!!!!!!!! I'm so pissed off right now. I command them to move and I can hear the actuators but the flaps don't move. Springs aren't broken. I've looked in my WIS/ASRA and there is no procedure to replace the actuators (that's another story - how hard it is to find anything in Mercedes Service Manuals). I've tried everything from holding it loosely while commanding the change to mounting it tightly and letting the spring fall into the grooves itself and also setting the flap halfway and trying to get the spring to catch it as it turns. Nothing works. The actuators work fine when dangling on the harness disconnected from the flaps. I don't know how these techs at Mercedes make any money. Everything is so unbelievably hard to work on. I guess that's why it's $250 an hour. It's worth it.
I need a drink!
I think we all feel your frustration. In these cases it is probably best to do what you're doing -- send it to a professional! Before it goes in, I would decide (personally) what it's worth to fix... I think there is some value to it working right, but is it worth $3000 to you? Good luck!!
I think we all feel your frustration. In these cases it is probably best to do what you're doing -- send it to a professional! Before it goes in, I would decide (personally) what it's worth to fix... I think there is some value to it working right, but is it worth $3000 to you? Good luck!!
Thanks, I needed that. I'm hoping if it's both actuators bad then it will be covered. If not, $1000 max for 2 actuators and installation customer pay. If covered by aftermarket warranty it's a $200 deductible.
You could just cut them off and take them out fully.
like a flaperectomy
I seriously was about to perform a flying flaperectomy as they were about to go flying across the yard.
I'm still pissed.
The springs should just line up with the grooves and mount right together but NOOOOOO.
ok, lube up the sides and push it open with a long screwdriver, or take off the actuators (on the sides) and be done with flaps 100%
Fixed.
Slept on it and still couldn't get things back together properly today. The springs just won't line up with flap grooves and then it turns the wrong way when you want them to slip together. Yes I have the right part on the correct side. 2 Different part numbers. I even tried letting the actuators turn a little then disconnecting it and that still didn't work. I sure would like to know how these things go together.
I removed the actuators and set the flaps to open.
Test drove.
No CEL or limp mode and flaps stayed open even under WOT. Eventually they will just stick open from not moving.
Only cost me 5 years of my life, a sore hand and back.
Who needs these things anyway. I hear no difference in the exhaust note and now I have no exhaust restrictions. I can live with stored codes and no messages or warnings.
Plus the noise they made is gone now.
Last edited by MBGuy2022; Apr 13, 2023 at 11:59 AM.
Dumb question ... what is the purpose of this (these) flaps anyway? Is this something new to the facelift cars or was it used in MY 2014 - 17 also?
Also makes me wonder, we saw in a recent thread an extended warranty announcement for the "exhaust valve assembly". No one on that thread was clear what that was exactly, is it possible it's this/these flaps?
They don’t make all that much of a difference although my e450 which also has this setup opens them when put into sport plus mode and it does have a nice little rumble when idling with the flaps open. Unfortunately the s560 does not have a sport plus mode just sport and sport does not open the flaps at lower throttle positions so the only way they seem to open without modification such as a tune or coding via xentry is at wide open throttle as far as I know. Very tempting to do a tune just to get these to stay open full time. I dunno anyone who would do this through coding although I did start using a new dealer today who may help me with this if I asked them. They seemed very customer friendly which in this day and age is a big deal.
They don’t make all that much of a difference although my e450 which also has this setup opens them when put into sport plus mode and it does have a nice little rumble when idling with the flaps open. Unfortunately the s560 does not have a sport plus mode just sport and sport does not open the flaps at lower throttle positions so the only way they seem to open without modification such as a tune or coding via xentry is at wide open throttle as far as I know. Very tempting to do a tune just to get these to stay open full time. I dunno anyone who would do this through coding although I did start using a new dealer today who may help me with this if I asked them. They seemed very customer friendly which in this day and age is a big deal.
Took the beast in last week for the exhaust flap actuators. Found out they are not covered by most aftermarket warranties because they are part of the exhaust system. My dealer wanted $1,600 to replace both of them. Parts alone were over $1,000 dollars. I declined the repair and purchased both factory actuators from mbpartsource.com for $473 delivered. The are easy to remove and install if the new ones will line up with the flaps like they should. Both of mine have a broken mounting ear on them and don't line up anymore. Part # 2229067503 for the LH actuator and 2229067403 for the RH actuator. $232 ea.
There is a difference in the exhaust note at low speeds if you leave the flaps open. You will hear a bit more moan from the exhaust. They are designed to open at higher RPM's to allow better breathing.
After spending most of the day trying to fix the flaps myself I have decided to let Mercedes handle it. The flaps are moving easily now after lubricating and freeing both of them up but the actuator springs WILL NOT LOCK ONTO THE FLAPS CORRECTLY!!!!!!!!!!!!!! I'm so pissed off right now. I command them to move and I can hear the actuators but the flaps don't move. Springs aren't broken. I've looked in my WIS/ASRA and there is no procedure to replace the actuators (that's another story - how hard it is to find anything in Mercedes Service Manuals). I've tried everything from holding it loosely while commanding the change to mounting it tightly and letting the spring fall into the grooves itself and also setting the flap halfway and trying to get the spring to catch it as it turns. Nothing works. The actuators work fine when dangling on the harness disconnected from the flaps. I don't know how these techs at Mercedes make any money. Everything is so unbelievably hard to work on. I guess that's why it's $250 an hour. It's worth it.
I need a drink!
If you really want to scream watch an experienced MB tech do the work that seems just this side of impossible. See the pro make it look as child’s play.
Fixed.
Slept on it and still couldn't get things back together properly today. The springs just won't line up with flap grooves and then it turns the wrong way when you want them to slip together. Yes I have the right part on the correct side. 2 Different part numbers. I even tried letting the actuators turn a little then disconnecting it and that still didn't work. I sure would like to know how these things go together.
I removed the actuators and set the flaps to open.
Test drove.
No CEL or limp mode and flaps stayed open even under WOT. Eventually they will just stick open from not moving.
Only cost me 5 years of my life, a sore hand and back.
Who needs these things anyway. I hear no difference in the exhaust note and now I have no exhaust restrictions. I can live with stored codes and no messages or warnings.
Plus the noise they made is gone now.
I'm dealing with this problem on my 2018 S560. My understanding is that the springs break and need to be replaced once the flaps are freed up. Did you have to remove the mufflers to get to the flap motors, or can you just lower them a bit? TIA
Probably better off just leaving them alone they don't make all that much of a difference. At times I've thought about putting a pair of flow master mufflers on the car to make it sound better but I'm afraid in doing so might create resonance vibration which you really don't want to have in a luxury car.
Am in process of fixing this on my 2018 S560. You have to drop the mufflers down pretty far to really get to the actuators. Basically, an uninstall of the rear exhaust system except I didn't remove it from the clamps.
And, wow, those flaps were seriously stuck! I used the universal socket (mentioned in this thread, I think) to start to get it loose. I sprayed the flap joints inside the exhaust pipe with a WD40 liquid lithium grease, good to 300F (not the classic WD40). Get them loose to the point you can easily open and close the flap with your fingers. Takes a while. The flap itself is part of the muffler and not otherwise repairable. If you go to a dealer, make sure they're not just replacing the entire muffler.
I had bought a set of replacement springs because I heard that the old ones often break when the flap seizes up. Glad I did even though the old ones weren't broken they were crushed down to about half the height of the new ones. When you reinstall the motor it's important that there be spring tension against the motor to keep the spring seated. Also make sure that the spring is properly seated in the flap disc notches on both sides as you install the motor.
The flaps were in odd positions when aligned to the motors on reinstall. Started the car and they both opened. Good sign.
Today, I put the exhaust system back up in place to finish the job.
Need to drop mufflers pretty far down. New spring came with new lock nuts. The original nuts were badly rusted.
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