Need help with CEL fault codes P0108 P0238
Need help with CEL fault codes P0108 P0238
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C63 AMG
Going to hate this say this, but if you have a 2019 like Ansonkk1; it wouldn't hurt to remove the tune and see if the codes are still there. It's not worth it to be permanently flagged for 4 hours of work installing the Dinan tune.
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From: Houston, TX
'15 C63S
I had similar codes (P0108 and P2A0D), and it ended up being that the pressure sensor(s) on the intercooler had gone bad. It would only throw the codes when I was running the Eurocharged tune, and it didn't throw any when flashed back to stock. The codes stopped once the sensors were replaced, both when stock and with the tune.
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From: CA
W213 E63
I had similar codes (P0108 and P2A0D), and it ended up being that the pressure sensor(s) on the intercooler had gone bad. It would only throw the codes when I was running the Eurocharged tune, and it didn't throw any when flashed back to stock. The codes stopped once the sensors were replaced, both when stock and with the tune.
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Joined: Jun 2015
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From: Houston, TX
'15 C63S
Your second code is different than mine (P0238 instead of P2A0D), so your issue could be the other pressure sensors that are located on the top/back of the intake. There are 4 pressure sensors on our cars; 2 by the intercooler, and 2 by the intake. My issue was the intercooler sensors, and I'm completely speculating here but your issue could be the intake sensors. On each side of the intake near the back (closest to the windshield), there is a small cover that you can snap off. There is a pressure sensor under each of those covers.
And as for the tune, I would get the codes with the tune. No codes when stock. After replacing the sensors, no code with tune or stock.
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From: CA
W213 E63
I'm on my phone right now and am going off of memory, but they were the sensors near the intake intercoolers. The dealer had to remove the reservoir for the secondary cooling circuit (the reservoir in the middle near the turbos) and a bunch of other stuff around that area to access the sensors. It isn't something you can easily do on your own.
Your second code is different than mine (P0238 instead of P2A0D), so your issue could be the other pressure sensors that are located on the top/back of the intake. There are 4 pressure sensors on our cars; 2 by the intercooler, and 2 by the intake. My issue was the intercooler sensors, and I'm completely speculating here but your issue could be the intake sensors. On each side of the intake near the back (closest to the windshield), there is a small cover that you can snap off. There is a pressure sensor under each of those covers.
And as for the tune, I would get the codes with the tune. No codes when stock. After replacing the sensors, no code with tune or stock.
Your second code is different than mine (P0238 instead of P2A0D), so your issue could be the other pressure sensors that are located on the top/back of the intake. There are 4 pressure sensors on our cars; 2 by the intercooler, and 2 by the intake. My issue was the intercooler sensors, and I'm completely speculating here but your issue could be the intake sensors. On each side of the intake near the back (closest to the windshield), there is a small cover that you can snap off. There is a pressure sensor under each of those covers.
And as for the tune, I would get the codes with the tune. No codes when stock. After replacing the sensors, no code with tune or stock.
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From: Houston, TX
'15 C63S
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From: CA
W213 E63
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2017 C63S AMG
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AMG C63S T-Model
I had similar codes (P0108 and P2A0D), and it ended up being that the pressure sensor(s) on the intercooler had gone bad. It would only throw the codes when I was running the Eurocharged tune, and it didn't throw any when flashed back to stock. The codes stopped once the sensors were replaced, both when stock and with the tune.
but since this codes, i dont have always max. Boost on the display (around 70–100%) and the car is a little bit slower 0,3–0,5s 100–200kmh.
could be these 2 codes for slower times?
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From: Houston, TX
'15 C63S
I only had two symptoms with this sensor issue (other than the codes). One would happen when I'd run the car hard and get the code. You could easily feel drop in power as if I lifted off the throttle for half a second. It's happen instantly though, and the gauge would still be showing full boost because I was getting overboost. The second symptom was on cold start-up. When I would first pull away, the turbos would build boost very, very quickly even with the slightest amount of throttle. The gauge would bounce between half and full boost, you could hear the turbos whistling under the hood, but I'd be inching along at 10 mph with my foot barely on the throttle. Once I came to a stop after going a few hundred feet, it'd stop and go bavk to normal.
Changing out the pressure sensors solved both those issues.
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I never had issues with a lack of boost, if anything I was getting overboost (too much pressure).
I only had two symptoms with this sensor issue (other than the codes). One would happen when I'd run the car hard and get the code. You could easily feel drop in power as if I lifted off the throttle for half a second. It's happen instantly though, and the gauge would still be showing full boost because I was getting overboost. The second symptom was on cold start-up. When I would first pull away, the turbos would build boost very, very quickly even with the slightest amount of throttle. The gauge would bounce between half and full boost, you could hear the turbos whistling under the hood, but I'd be inching along at 10 mph with my foot barely on the throttle. Once I came to a stop after going a few hundred feet, it'd stop and go bavk to normal.
Changing out the pressure sensors solved both those issues.
I only had two symptoms with this sensor issue (other than the codes). One would happen when I'd run the car hard and get the code. You could easily feel drop in power as if I lifted off the throttle for half a second. It's happen instantly though, and the gauge would still be showing full boost because I was getting overboost. The second symptom was on cold start-up. When I would first pull away, the turbos would build boost very, very quickly even with the slightest amount of throttle. The gauge would bounce between half and full boost, you could hear the turbos whistling under the hood, but I'd be inching along at 10 mph with my foot barely on the throttle. Once I came to a stop after going a few hundred feet, it'd stop and go bavk to normal.
Changing out the pressure sensors solved both those issues.
I am thinking that it is the MAP sensors in the intercooler that is my best guess at the moment as you had the exact same codes as i am getting, and i may be overboosting like you said as well.
Did you have any of these issues/symptoms?? My symptoms are better described by this post (link attached below), where others are having the same issue but they are not getting any codes like we did. Please let me know.
https://mbworld.org/forums/c63-c63s-...ration-10.html
I am dropping my car off at independent shop tomorrow to replace the 2 map sensors in the intercooler and will update if this solves my jiddering odd issue.
Any other information on this matter will be a great help! Thanks!
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From: Houston, TX
'15 C63S
Hey friend, i hope you see this. I am currently having the same exact codes as you were p0108 and p2a0d, my issue with the car being it stutters or sounds like misfiring at lower rpms. if you are on the interstate on comfort cruising and give it gas or even accelerating to interstate speed you will definetly feel a jerkyness or jiddering with the engine and can audibly hear it.
I am thinking that it is the MAP sensors in the intercooler that is my best guess at the moment as you had the exact same codes as i am getting, and i may be overboosting like you said as well.
Did you have any of these issues/symptoms?? My symptoms are better described by this post (link attached below), where others are having the same issue but they are not getting any codes like we did. Please let me know.
https://mbworld.org/forums/c63-c63s-...ration-10.html
I am dropping my car off at independent shop tomorrow to replace the 2 map sensors in the intercooler and will update if this solves my jiddering odd issue.
Any other information on this matter will be a great help! Thanks!
I am thinking that it is the MAP sensors in the intercooler that is my best guess at the moment as you had the exact same codes as i am getting, and i may be overboosting like you said as well.
Did you have any of these issues/symptoms?? My symptoms are better described by this post (link attached below), where others are having the same issue but they are not getting any codes like we did. Please let me know.
https://mbworld.org/forums/c63-c63s-...ration-10.html
I am dropping my car off at independent shop tomorrow to replace the 2 map sensors in the intercooler and will update if this solves my jiddering odd issue.
Any other information on this matter will be a great help! Thanks!
When my car was having it's issues with those codes, it was only when the ECU was tuned (Eurocharged Stage 2). If it was flashed back to stock, it never had any issues, even before the sensors were replaced. Once the MAP sensors by the intercoolers were replaced, I never saw those codes again (stock or tuned).
As for drivability issues, I never noticed any sort of jerkiness at any speeds except under full throttle. It'd stutter somewhat hard, throw the codes, and then I'd see the engine oil and transmission fluid temps rise above what it'd typically (trans cooler line is tired into those the same circuit as the intercooler that cools the intake air, if I remember correctly). Nothing huge, but it'd run 8F-10F above normal for 5-10 minutes.
With those codes, you're getting a misfire and an overboost reading. For whatever reason, the turbo is boosting harder than the ECU thinks it is based on the readings it has. It's more than likely a sensor that has failed and is giving the ECU bad readings.
As for that other thread talking about replacing the wet clutch and/or flushing the transmission fluid, you wouldn't be getting the overboost code if there wasn't some sort of issue on the intake/fuel/boost side with the engine. It wouldn't be a transmission issue. Don't listen to them.
Last edited by msd3075; Aug 15, 2025 at 02:59 PM.
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It's been over 5 years since I sold my C63S, so I'm going completely off of what I can remember from back them.
When my car was having it's issues with those codes, it was only when the ECU was tuned (Eurocharged Stage 2). If it was flashed back to stock, it never had any issues, even before the sensors were replaced. Once the MAP sensors by the intercoolers were replaced, I never saw those codes again (stock or tuned).
As for drivability issues, I never noticed any sort of jerkiness at any speeds except under full throttle. It'd stutter somewhat hard, throw the codes, and then I'd see the engine oil and transmission fluid temps rise above what it'd typically (trans cooler line is tired into those the same circuit as the intercooler that cools the intake air, if I remember correctly). Nothing huge, but it'd run 8F-10F above normal for 5-10 minutes.
With those codes, you're getting a misfire and an overboost reading. For whatever reason, the turbo is boosting harder than the ECU thinks it is based on the readings it has. It's more than likely a sensor that has failed and is giving the ECU bad readings.
As for that other thread talking about replacing the wet clutch and/or flushing the transmission fluid, you wouldn't be getting the overboost code if there wasn't some sort of issue on the intake/fuel/boost side with the engine. It wouldn't be a transmission issue. Don't listen to them.
When my car was having it's issues with those codes, it was only when the ECU was tuned (Eurocharged Stage 2). If it was flashed back to stock, it never had any issues, even before the sensors were replaced. Once the MAP sensors by the intercoolers were replaced, I never saw those codes again (stock or tuned).
As for drivability issues, I never noticed any sort of jerkiness at any speeds except under full throttle. It'd stutter somewhat hard, throw the codes, and then I'd see the engine oil and transmission fluid temps rise above what it'd typically (trans cooler line is tired into those the same circuit as the intercooler that cools the intake air, if I remember correctly). Nothing huge, but it'd run 8F-10F above normal for 5-10 minutes.
With those codes, you're getting a misfire and an overboost reading. For whatever reason, the turbo is boosting harder than the ECU thinks it is based on the readings it has. It's more than likely a sensor that has failed and is giving the ECU bad readings.
As for that other thread talking about replacing the wet clutch and/or flushing the transmission fluid, you wouldn't be getting the overboost code if there wasn't some sort of issue on the intake/fuel/boost side with the engine. It wouldn't be a transmission issue. Don't listen to them.
What car do you upgrade to? I will update you after the sensor swap tomorrow if this was the remedy for the codes and issues. Thank you so much for the response!
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Joined: Jun 2015
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From: Houston, TX
'15 C63S
Thank you!!! Its a high quote in just labor just to get to the intercooler sensors unfortunately, $20 sensors but $930 in labor just to replace the sensors. But if it fixes it i dont mind it. At low rpms or trying to do full throttle is when i stutter and misfire type of symptoms, i can audibly hear it in the exhaust as well, not sure if you were catless and could hear it as clear as i can.
What car do you upgrade to? I will update you after the sensor swap tomorrow if this was the remedy for the codes and issues. Thank you so much for the response!
What car do you upgrade to? I will update you after the sensor swap tomorrow if this was the remedy for the codes and issues. Thank you so much for the response!
My car was stock other than the Eurocharged tune, but I could hear it in the exhaust too even with stock exhaust.
As for an upgrade from the C63S, I drive a GMC Canyon pickup truck now. Needed it for site visits for work. Planned on getting a fun weekend vehicle to compliment it, but Covid happened, priorities changed a bit, and that spot in the garage quickly filled up with all my kid's crap. Maybe one day soon, we'll see.
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Not sure if your shop will do it the same, but when I had my sensors replaced, the dealer had to pretty much pull the entire front of the car off to access the sensors. Bumper, radiator and most of the cooling system. He even messed up the small auxiliary coolant reservoir that sits atop the engine when he was taking it apart (was done under warranty, don't ask), so had to replace that too. It was a very labor-intensive job to swap out a tiny sensor in 10 seconds.
My car was stock other than the Eurocharged tune, but I could hear it in the exhaust too even with stock exhaust.
As for an upgrade from the C63S, I drive a GMC Canyon pickup truck now. Needed it for site visits for work. Planned on getting a fun weekend vehicle to compliment it, but Covid happened, priorities changed a bit, and that spot in the garage quickly filled up with all my kid's crap. Maybe one day soon, we'll see.
My car was stock other than the Eurocharged tune, but I could hear it in the exhaust too even with stock exhaust.
As for an upgrade from the C63S, I drive a GMC Canyon pickup truck now. Needed it for site visits for work. Planned on getting a fun weekend vehicle to compliment it, but Covid happened, priorities changed a bit, and that spot in the garage quickly filled up with all my kid's crap. Maybe one day soon, we'll see.
Good lord, I sure hope that isnt needed for mine but who knows. i hear you on the aux tank, i disassembled many things to try and reach it myself and couldnt get to it. Not enough space at all. Upon reassembly i too broke the return like plastic piece on the aux tank small, smh. but it isnt pressurized so i am just going to fix the tank myself rather than replace as that is a huge job to replace the tank since it is connected middle of the engine in between the intercoolers.
I too am looking to get out of this cool car performance car passion of mine, its just an arm and leg for every little thing and just kills it for me. I am just going to sell or trade it for a tesla model s plaid and be done.
As for site visits, sounds like you are in building. I am in general contracting building luxury homes in Nashville.
Thanks for all your responses, I will proceed with the repair tomorrow and pray it solves the issue and report back. Take care brother
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Just an update, replaced the map sensors in the intercooler and now the codes are gone and the engine is back to powerful and running correctly, but now my issue remains with the transmission jerkiness under acceleration. No one seems to know what the fix is so who knows how much time or money it will take to fix that issue.
