CEL for an issue with the electric compressor (M256/E53)
Thread Starter
Member
Joined: Mar 2025
Posts: 149
Likes: 43
From: Los Angeles
2020 E53 AMG Sedan
CEL for an issue with the electric compressor (M256/E53)
Was just driving home casually through the neighborhood last night and got a CEL. Took it to my indie shop for diagnostic who pulled the code and got a P176D09 code for "The electric additional compressor has a malfunction. There is a component fault."
I have a CPO warranty still so took to the dealer (unfortunately with the CEL cleared) and the CEL did not come back on the drive. They are going to try diagnosing without the CEL and pulling the logs to see it along with my pics with the code. I'm optimistic that it's going to be covered under warranty if it's something with the electric compressor (supercharger?). Tried poking around online and have not seen any other reports of similar so curious if other E53 or M256 people have had this before so started a thread.
I have a CPO warranty still so took to the dealer (unfortunately with the CEL cleared) and the CEL did not come back on the drive. They are going to try diagnosing without the CEL and pulling the logs to see it along with my pics with the code. I'm optimistic that it's going to be covered under warranty if it's something with the electric compressor (supercharger?). Tried poking around online and have not seen any other reports of similar so curious if other E53 or M256 people have had this before so started a thread.
Out Of Control!!
Joined: Jun 2004
Posts: 13,799
Likes: 3,229
2014 E63S; AMS 100 octane ECU dyno tune; EDOK TCU tune; BB intakes; sprintbooster
Several reports for CEL with '53's and. 450's for various reasons ... frustrating
https://mbworld.org/forums/e-class-w...ine-light.html
https://mbworld.org/forums/e-class-w...epeatedly.html
https://mbworld.org/forums/e-class-w...ine-light.html
https://mbworld.org/forums/e-class-w...epeatedly.html
Last edited by PeterUbers; Nov 7, 2025 at 05:51 PM.
Thread Starter
Member
Joined: Mar 2025
Posts: 149
Likes: 43
From: Los Angeles
2020 E53 AMG Sedan
Several reports for CEL with '53's and. 450's for various reasons ... frustrating
https://mbworld.org/forums/e-class-w...ine-light.html
https://mbworld.org/forums/e-class-w...epeatedly.html
https://mbworld.org/forums/e-class-w...ine-light.html
https://mbworld.org/forums/e-class-w...epeatedly.html
Thread Starter
Member
Joined: Mar 2025
Posts: 149
Likes: 43
From: Los Angeles
2020 E53 AMG Sedan
final update: was not the AC compressor the SA misspoke. replaced 256-090-60-00 all under CPO warranty
would have been $4-5k without. definitely looking into extended warranty now
would have been $4-5k without. definitely looking into extended warranty now
Newbie
Joined: Nov 2025
Posts: 2
Likes: 0
I have the same problem. Did you get any more details on what exactly the fault was. From what I have read online it mentions it could be a fault in the open circuit. 5k Sounds like they replaced the whole electrical supercharger.
Thread Starter
Member
Joined: Mar 2025
Posts: 149
Likes: 43
From: Los Angeles
2020 E53 AMG Sedan
no visual issues present, so they did a manual actuation test which it did not respond to. then tested the voltage check which was okay. tested the resistance at 90 ohms which indicated an internal fault. to my understanding of electric motors that sounds like there was most likely a breakdown in the windings and it failed open, which won't allow the motor to function. they replaced the whole part. it's quite a lot of labor to get to the unit. i'm not aware of the specific root cause of the failure but i'm guessing the heat or whatever caused some winding somewhere to short and fail
Trending Topics
Newbie
Joined: Nov 2025
Posts: 2
Likes: 0
yes they tested it, got code P176D09
no visual issues present, so they did a manual actuation test which it did not respond to. then tested the voltage check which was okay. tested the resistance at 90 ohms which indicated an internal fault. to my understanding of electric motors that sounds like there was most likely a breakdown in the windings and it failed open, which won't allow the motor to function. they replaced the whole part. it's quite a lot of labor to get to the unit. i'm not aware of the specific root cause of the failure but i'm guessing the heat or whatever caused some winding somewhere to short and fail
no visual issues present, so they did a manual actuation test which it did not respond to. then tested the voltage check which was okay. tested the resistance at 90 ohms which indicated an internal fault. to my understanding of electric motors that sounds like there was most likely a breakdown in the windings and it failed open, which won't allow the motor to function. they replaced the whole part. it's quite a lot of labor to get to the unit. i'm not aware of the specific root cause of the failure but i'm guessing the heat or whatever caused some winding somewhere to short and fail
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Member
Joined: Mar 2025
Posts: 149
Likes: 43
From: Los Angeles
2020 E53 AMG Sedan
i'm not sure if it's too hard to tackle on your own, the part they replaced for me is only around $1000: https://www.mbpartsgiant.com/genuine...sor~2560906000
an indie shop near me originally quoted me ~$4k but i was able to get it covered under CPO so had the dealer do it
Newbie
Joined: Aug 2025
Posts: 2
Likes: 0
E53 amg coupé
Hey there!
I have the same error code on my 2021 E53 AMG Coupé. My car does not have warranty anymore sadly.
I also have a weird , loud whistling noise under heavy acceleration usually above 5k RPM. Had this sound for 4 months now but theres absolutely no power loss.
I have a good mechanic who's going to look into it next week. Might be a leak from the compressor to the turbo... not sure. I really hope the part does not need to be replaced...
Did you hear any weird sounds while the error code was there?
Thank you in advance!
Thread Starter
Member
Joined: Mar 2025
Posts: 149
Likes: 43
From: Los Angeles
2020 E53 AMG Sedan
Hey there!
I have the same error code on my 2021 E53 AMG Coupé. My car does not have warranty anymore sadly.
I also have a weird , loud whistling noise under heavy acceleration usually above 5k RPM. Had this sound for 4 months now but theres absolutely no power loss.
I have a good mechanic who's going to look into it next week. Might be a leak from the compressor to the turbo... not sure. I really hope the part does not need to be replaced...
Did you hear any weird sounds while the error code was there?
Thank you in advance!
I have the same error code on my 2021 E53 AMG Coupé. My car does not have warranty anymore sadly.
I also have a weird , loud whistling noise under heavy acceleration usually above 5k RPM. Had this sound for 4 months now but theres absolutely no power loss.
I have a good mechanic who's going to look into it next week. Might be a leak from the compressor to the turbo... not sure. I really hope the part does not need to be replaced...
Did you hear any weird sounds while the error code was there?
Thank you in advance!
post what the outcome is once you know, will help others in the future
