Help! M16/7 recirculating air flap; p208E code
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Joined: May 2018
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87 Grand National; 2006 e55
Help! M16/7 recirculating air flap; p208E code
Hey all....need some help:
I did lots of searching on this topic, but it seems quite rare on the M113k. I see far more info related to the c32 kompressors. My car is an 06 E55, fyi.
Issue is zero boost...none at all. Supercharger clutch is not engaging. Car was fine one day, and then no boost the next. Runs great otherwise, just naturally aspirated. Zero boost.
I do have STAR, and am coming up w/error code p208e which is m16/7 recirculating air flap electrical fault.
I performed some of the guided STAR tests. The percentage/angle of the flap doesn't really changed when given manual input via STAR. It stays around 59-60% regardless, w/ tiny changes to percentage. There is a voltage test also via STAR, and the voltage values seem higher than the normal given range listed by STAR.
I checked all fuses in the trunk (all good), and tried disconnecting the battery. Same issue/same code. I pulled the surge tanks and checked wiring back there. Nothing appears pinched or burnt. I'm now at a loss. I just want to eliminate all other options before going through the expense of buying a bypass valve/flap, and all of the associated work, solely based on an educated guess. It looks like the supercharger assembly has to be removed completely.
Is there anything else that would essentially disable this flap, and throw this code? Bypass flap failure seems quite rare on this platform.
Thanks to all in advance. Any help or guidance is appreciated.
-Chris
I did lots of searching on this topic, but it seems quite rare on the M113k. I see far more info related to the c32 kompressors. My car is an 06 E55, fyi.
Issue is zero boost...none at all. Supercharger clutch is not engaging. Car was fine one day, and then no boost the next. Runs great otherwise, just naturally aspirated. Zero boost.
I do have STAR, and am coming up w/error code p208e which is m16/7 recirculating air flap electrical fault.
I performed some of the guided STAR tests. The percentage/angle of the flap doesn't really changed when given manual input via STAR. It stays around 59-60% regardless, w/ tiny changes to percentage. There is a voltage test also via STAR, and the voltage values seem higher than the normal given range listed by STAR.
I checked all fuses in the trunk (all good), and tried disconnecting the battery. Same issue/same code. I pulled the surge tanks and checked wiring back there. Nothing appears pinched or burnt. I'm now at a loss. I just want to eliminate all other options before going through the expense of buying a bypass valve/flap, and all of the associated work, solely based on an educated guess. It looks like the supercharger assembly has to be removed completely.
Is there anything else that would essentially disable this flap, and throw this code? Bypass flap failure seems quite rare on this platform.
Thanks to all in advance. Any help or guidance is appreciated.
-Chris
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Joined: Nov 2006
Posts: 143
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From: Michigan
05E55-05CL500-02E430
https://mbworld.org/forums/c-class-w...-actuator.html
is this your issue
is this your issue
Thread Starter
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Joined: May 2018
Posts: 89
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87 Grand National; 2006 e55
https://mbworld.org/forums/c-class-w...-actuator.html
is this your issue
is this your issue
I know where the bypass flap is, but what I am trying to ascertain is if mine has stopped closing/functioning due to another issue. A mechanical failure seems VERY rare on the M113k, so I'm trying to rule out any other causes. Thank you, though.
Any other help is GREATLY appreciated.
Thread Starter
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Joined: May 2018
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87 Grand National; 2006 e55
I'm guessing not alot of folks have encountered this issue. In that case, one quick question:
Is the recirulating bypass flap the exact same part across all the M113k platforms and model years? (E55, S55, CL55, SL55, etc)
Is the recirulating bypass flap the exact same part across all the M113k platforms and model years? (E55, S55, CL55, SL55, etc)
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Sl55 amg 2002
Thanks for the link. I saw that one in my search, but it wasn't much help, unfortunately. Different platform, and they were just looking for the location.
I know where the bypass flap is, but what I am trying to ascertain is if mine has stopped closing/functioning due to another issue. A mechanical failure seems VERY rare on the M113k, so I'm trying to rule out any other causes. Thank you, though.
Any other help is GREATLY appreciated.
I know where the bypass flap is, but what I am trying to ascertain is if mine has stopped closing/functioning due to another issue. A mechanical failure seems VERY rare on the M113k, so I'm trying to rule out any other causes. Thank you, though.
Any other help is GREATLY appreciated.
Thread Starter
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Joined: May 2018
Posts: 89
Likes: 5
87 Grand National; 2006 e55
Yes, I did. I swapped in a used bypass, along with a new wiring harness for it. Problem solved. Prior to doing the swap, I used STAR to attempt to move the bypass throttle blade. It would not close when commanded, so I went ahead with the wrenching.
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Sl55 amg 2002
Like where is the bypass located
Last edited by Tylerhayles; Jul 11, 2021 at 06:52 AM.
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Thread Starter
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Joined: May 2018
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87 Grand National; 2006 e55
That is your main throttle body. I am referring to the secondary bypass valve/air flap (basically a throttle body) under the blower, as previously mentioned.
That is the one the code references, as well.
That is the one the code references, as well.
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Sl55 amg 2002
so im guessing if thats faulty its charger out to replace it? Do we have part numbers for it by anychance
Thread Starter
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Joined: May 2018
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87 Grand National; 2006 e55
I don't think you should guess on this one. See if you can get a hold of STAR, and command it to open and close. Just because you are seeing it open when the car is off does not mean it isn't working properly, when running; going in/out of boost conditions. As a general rule, I wouldn't throw parts at these cars without doing some level of diagnosis first.
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Sl55 amg 2002
I don't think you should guess on this one. See if you can get a hold of STAR, and command it to open and close. Just because you are seeing it open when the car is off does not mean it isn't working properly, when running; going in/out of boost conditions. As a general rule, I wouldn't throw parts at these cars without doing some level of diagnosis first.
with the throttle body off so i can see the m16/7 nothing moves or closes it just stays open,
is the multiplug connector loom a pain to change or isit routed fairly easy
what
else can cause it to malfunction then? Its only the loom and the m16/7 itsself right? So its either wiring or the bypass itsself?
Member
Joined: Apr 2017
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Sl55 amg 2002
I don't think you should guess on this one. See if you can get a hold of STAR, and command it to open and close. Just because you are seeing it open when the car is off does not mean it isn't working properly, when running; going in/out of boost conditions. As a general rule, I wouldn't throw parts at these cars without doing some level of diagnosis first.
i see you said you swapped the wiring harness aswelll, was this from the sam to the throttlebody
Super Member
Joined: Aug 2018
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From: Seattle, WA
2019 M5 Comp, 2005 Ariel Atom 2
I think that the wire harness for the bypass valve is part of the main engine wire harness, so to change it would require another engine wire harness. These don't go bad often, however I'm one of the exceptions as my car was having issues with the main TB and I found the part of the loom under the intake had gotten brittle and some wires were exposed and corroding.
When you say 'new aftermarket' are we talking Bosch, same as OE, or is it a different brand? Our cars don't like non-OE electronic components in them, but if it's Bosch you should be good.
2 Questions - when you put the key in and turn it to 'on' (but not start the engine), after 15-30 seconds you should see the main TB butterfly open and shut, then hear audible clicking and movement from the bypass valve too, this is how they go through their learning procedure. See if you've got movement on both, and it's possible it just hasn't learned the new one yet. If you have a multimeter you can see what voltage is going to the bypass valve, if there is none then I'd look at a wiring issue.
Is your car tuned at all, or are you running the stock throttle body and pulley?
When you say 'new aftermarket' are we talking Bosch, same as OE, or is it a different brand? Our cars don't like non-OE electronic components in them, but if it's Bosch you should be good.
2 Questions - when you put the key in and turn it to 'on' (but not start the engine), after 15-30 seconds you should see the main TB butterfly open and shut, then hear audible clicking and movement from the bypass valve too, this is how they go through their learning procedure. See if you've got movement on both, and it's possible it just hasn't learned the new one yet. If you have a multimeter you can see what voltage is going to the bypass valve, if there is none then I'd look at a wiring issue.
Is your car tuned at all, or are you running the stock throttle body and pulley?
Member
Joined: Apr 2017
Posts: 92
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Sl55 amg 2002
I think that the wire harness for the bypass valve is part of the main engine wire harness, so to change it would require another engine wire harness. These don't go bad often, however I'm one of the exceptions as my car was having issues with the main TB and I found the part of the loom under the intake had gotten brittle and some wires were exposed and corroding.
When you say 'new aftermarket' are we talking Bosch, same as OE, or is it a different brand? Our cars don't like non-OE electronic components in them, but if it's Bosch you should be good.
2 Questions - when you put the key in and turn it to 'on' (but not start the engine), after 15-30 seconds you should see the main TB butterfly open and shut, then hear audible clicking and movement from the bypass valve too, this is how they go through their learning procedure. See if you've got movement on both, and it's possible it just hasn't learned the new one yet. If you have a multimeter you can see what voltage is going to the bypass valve, if there is none then I'd look at a wiring issue.
Is your car tuned at all, or are you running the stock throttle body and pulley?
When you say 'new aftermarket' are we talking Bosch, same as OE, or is it a different brand? Our cars don't like non-OE electronic components in them, but if it's Bosch you should be good.
2 Questions - when you put the key in and turn it to 'on' (but not start the engine), after 15-30 seconds you should see the main TB butterfly open and shut, then hear audible clicking and movement from the bypass valve too, this is how they go through their learning procedure. See if you've got movement on both, and it's possible it just hasn't learned the new one yet. If you have a multimeter you can see what voltage is going to the bypass valve, if there is none then I'd look at a wiring issue.
Is your car tuned at all, or are you running the stock throttle body and pulley?
so basically my old bypass is faulty, so i got a new kamoka one of autodoc which corresponds with the part number that was on mine,
i will double check the clicking on both throttle bodys i defo remember hearing something clicking
il pull up star diagram and check what cable is power to the bypass, unless you happen to know off top of head?
My car is tuned yes
had a smaller pulley but im back to stock pulley now, changed a few months ago
and throttle body is stock
i have managed to find a used oe bosch bypass on ebay i will collect tomorrow, i maybe just sit it on top of the engine bay and plug the connector in and see if the code goes away, maybe its the non oe part causing it
the code that is coming up is m16/7 electrical fault
Last edited by Tylerhayles; Feb 8, 2022 at 04:25 PM.
Super Member
Joined: Aug 2018
Posts: 697
Likes: 172
From: Seattle, WA
2019 M5 Comp, 2005 Ariel Atom 2
Yeah that's a good idea, at least rule out the aftermarket unit as being a problem. I had my bypass fail and installed a used one years back and that fixed it for me.
I don't remember what cable is power, but with the key on you could probe all of them, one should have 5v or some kind of reference voltage just like the main TB.
RE tuning - did you revert back to a stock map after putting your stock pulley back on? It could be fighting itself if the car is tuned to see more air and boost, so I'd rule that one out too. With your code as an electrical fault and not a performance/range fault it is less likely, but still a possibility.
Good luck!
I don't remember what cable is power, but with the key on you could probe all of them, one should have 5v or some kind of reference voltage just like the main TB.
RE tuning - did you revert back to a stock map after putting your stock pulley back on? It could be fighting itself if the car is tuned to see more air and boost, so I'd rule that one out too. With your code as an electrical fault and not a performance/range fault it is less likely, but still a possibility.
Good luck!
Member
Joined: Apr 2017
Posts: 92
Likes: 4
Sl55 amg 2002
Yeah that's a good idea, at least rule out the aftermarket unit as being a problem. I had my bypass fail and installed a used one years back and that fixed it for me.
I don't remember what cable is power, but with the key on you could probe all of them, one should have 5v or some kind of reference voltage just like the main TB.
RE tuning - did you revert back to a stock map after putting your stock pulley back on? It could be fighting itself if the car is tuned to see more air and boost, so I'd rule that one out too. With your code as an electrical fault and not a performance/range fault it is less likely, but still a possibility.
Good luck!
I don't remember what cable is power, but with the key on you could probe all of them, one should have 5v or some kind of reference voltage just like the main TB.
RE tuning - did you revert back to a stock map after putting your stock pulley back on? It could be fighting itself if the car is tuned to see more air and boost, so I'd rule that one out too. With your code as an electrical fault and not a performance/range fault it is less likely, but still a possibility.
Good luck!
nope i havent managed to get back to a stock map yet only because i still have headers
etc so i left the map on , it was only a mild tune,
did you have to recode the bypass or was the used one plug and play
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87 Grand National; 2006 e55
Glad you fixed this....and sorry for the late reply, as it was my original thread a few years back. I had replaced the bypass valve and the wiring harness for the bypass. Being I had the blower off and everything apart, I didn't see a downside to swapping the harness, as the old one was quite brittle.
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Joined: Feb 2022
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CLS 55 amg
hi guys i have the code p208e and following this thread so i just did the swap with oem second hand bypass but still getting the error of the electronic fault i am lost help please
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Sl55 amg 2002
ahh what a nightmare sorry to hear, these poxy cars ay, so whats the exact code you are getting whats it saying? Electrical fault or potentiometer
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CLS 55 amg
the old bypass had p208e M16/7 electrical fault, p2095-001 potentiometer shorted to the battery.the new bypass has just p208e electrical fault
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Sl55 amg 2002
