17 C63 Multiple misfire, map sensors
Thread Starter
Senior Member
Joined: Jun 2019
Posts: 453
Likes: 91
From: DFW, Texas
2017 AMG C63
17 C63 Multiple misfire, map sensors
17 C63 36k mi. Only mods are JB4 on map 4 and E25, and Modal intakes. Car has run great for 2 years.
The other day out of the blue I had a check engine light appear. The car was running fine so I waited to see if it would just clear on its own thinking it was perhaps a random misfire. ( I would usually try to read and clear the code with the JB4 app, however the Bluetooth module I have isn't working currently so cannot.)
It hasn't gone away after several starts and ~ 100 mi driven since appeared. Then the last time I went to start it, the idle was rough.
So I went to Autozone to have the codes read/cleared. Came back with :
- mis firing cylinders (P0300, P0301 (/2/3/4/7) )
- a map sensor code (1 P2A0B)
- lost communication with ECM/PCM A (U0100)
The auto zone tool could not clear the codes.
Looking for any input on if someone, esp with a JB4 setup, has had similar codes or ideas on where to troubleshoot. Sounds like a bad connection or.elec problem somewhere based on the ECM code.
Thanks
The other day out of the blue I had a check engine light appear. The car was running fine so I waited to see if it would just clear on its own thinking it was perhaps a random misfire. ( I would usually try to read and clear the code with the JB4 app, however the Bluetooth module I have isn't working currently so cannot.)
It hasn't gone away after several starts and ~ 100 mi driven since appeared. Then the last time I went to start it, the idle was rough.
So I went to Autozone to have the codes read/cleared. Came back with :
- mis firing cylinders (P0300, P0301 (/2/3/4/7) )
- a map sensor code (1 P2A0B)
- lost communication with ECM/PCM A (U0100)
The auto zone tool could not clear the codes.
Looking for any input on if someone, esp with a JB4 setup, has had similar codes or ideas on where to troubleshoot. Sounds like a bad connection or.elec problem somewhere based on the ECM code.
Thanks
Last edited by LessIsMore; Mar 29, 2021 at 09:56 PM.
Thread Starter
Senior Member
Joined: Jun 2019
Posts: 453
Likes: 91
From: DFW, Texas
2017 AMG C63
Should have mentioned that, thanks - new plugs 5-7k mi. ago, abt 18 mos. ago. OEM plugs.
I didnt think it was likely that several plugs failed simultaneously. I have had no other codes or issues recently.
I didnt think it was likely that several plugs failed simultaneously. I have had no other codes or issues recently.
Last edited by LessIsMore; Mar 29, 2021 at 09:59 PM.
Junior Member
Joined: Jul 2020
Posts: 58
Likes: 17
From: Central CA
AMG C63s, e70 X5M, 335i,AMG glc63
I don't have a jb4 on my c63s but I do have one on my 335i, check the wiring on the jb4, make sure it still has a solid connection, check your coils and plugs. I've even had the jb4 case melt onto the circuit board. I haven't had this issue but others from other platforms complain about water getting inside the circuit board.
Thread Starter
Senior Member
Joined: Jun 2019
Posts: 453
Likes: 91
From: DFW, Texas
2017 AMG C63
I don't have a jb4 on my c63s but I do have one on my 335i, check the wiring on the jb4, make sure it still has a solid connection, check your coils and plugs. I've even had the jb4 case melt onto the circuit board. I haven't had this issue but others from other platforms complain about water getting inside the circuit board.
I have not been able to see anything wrong physically with the JB4 or connections. I had not touched it in a while prior to this episode. The case for the C63 version is billet aluminum instead of plastic, so no concerns about melting. I've sent a pic of the front and back of the board to Ando at BMS, waiting on reply.
Super Member
Joined: Jun 2015
Posts: 643
Likes: 92
From: Houston, TX
'15 C63S
17 C63 36k mi. Only mods are JB4 on map 4 and E25, and Modal intakes. Car has run great for 2 years.
The other day out of the blue I had a check engine light appear. The car was running fine so I waited to see if it would just clear on its own thinking it was perhaps a random misfire. ( I would usually try to read and clear the code with the JB4 app, however the Bluetooth module I have isn't working currently so cannot.)
It hasn't gone away after several starts and ~ 100 mi driven since appeared. Then the last time I went to start it, the idle was rough.
So I went to Autozone to have the codes read/cleared. Came back with :
- mis firing cylinders (P0300, P0301 (/2/3/4/7) )
- a map sensor code (1 P2A0B)
- lost communication with ECM/PCM A (U0100)
The auto zone tool could not clear the codes.
Looking for any input on if someone, esp with a JB4 setup, has had similar codes or ideas on where to troubleshoot. Sounds like a bad connection or.elec problem somewhere based on the ECM code.
Thanks
The other day out of the blue I had a check engine light appear. The car was running fine so I waited to see if it would just clear on its own thinking it was perhaps a random misfire. ( I would usually try to read and clear the code with the JB4 app, however the Bluetooth module I have isn't working currently so cannot.)
It hasn't gone away after several starts and ~ 100 mi driven since appeared. Then the last time I went to start it, the idle was rough.
So I went to Autozone to have the codes read/cleared. Came back with :
- mis firing cylinders (P0300, P0301 (/2/3/4/7) )
- a map sensor code (1 P2A0B)
- lost communication with ECM/PCM A (U0100)
The auto zone tool could not clear the codes.
Looking for any input on if someone, esp with a JB4 setup, has had similar codes or ideas on where to troubleshoot. Sounds like a bad connection or.elec problem somewhere based on the ECM code.
Thanks
I would get the CEL after running the car hard, especially when it was hot outside. Had the Eurocharged Stage 2 tune on my car when it did it, but it wouldn't throw any codes when it was flashed back to stock. That made it difficult because I couldn't get the dealer to diagnose the issue easily since I didn't want them plugging the car in while it was tuned. Figured when I was at 49K miles with the warranty almost up to go ahead and have them scan it. Ended up being one of the MAP sensors on the intercooler which is an absolute pain to get to. Never had another issue with those codes after the MAP sensor was changed, even while running the tune.
Thread Starter
Senior Member
Joined: Jun 2019
Posts: 453
Likes: 91
From: DFW, Texas
2017 AMG C63
Could be one of your MAP sensors is going out and needs to be replaced. Had the same misfire and MAP sensor codes on my car (except the MAP code was P2A0D and the misfire code was P0308).
I would get the CEL after running the car hard, especially when it was hot outside. Had the Eurocharged Stage 2 tune on my car when it did it, but it wouldn't throw any codes when it was flashed back to stock. That made it difficult because I couldn't get the dealer to diagnose the issue easily since I didn't want them plugging the car in while it was tuned. Figured when I was at 49K miles with the warranty almost up to go ahead and have them scan it. Ended up being one of the MAP sensors on the intercooler which is an absolute pain to get to. Never had another issue with those codes after the MAP sensor was changed, even while running the tune.
I would get the CEL after running the car hard, especially when it was hot outside. Had the Eurocharged Stage 2 tune on my car when it did it, but it wouldn't throw any codes when it was flashed back to stock. That made it difficult because I couldn't get the dealer to diagnose the issue easily since I didn't want them plugging the car in while it was tuned. Figured when I was at 49K miles with the warranty almost up to go ahead and have them scan it. Ended up being one of the MAP sensors on the intercooler which is an absolute pain to get to. Never had another issue with those codes after the MAP sensor was changed, even while running the tune.
The fact that the MAP sensor code is slightly different makes me hopeful that if I have a bad one, it is not one of the hard to reach ones! Who am I kidding, they are all hard to reach lol.
Was your misfire code only on cyl 8?
Did you also have any errors related to lack of communication with the ECM?
Last edited by LessIsMore; Apr 2, 2021 at 01:45 AM.
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Thread Starter
Senior Member
Joined: Jun 2019
Posts: 453
Likes: 91
From: DFW, Texas
2017 AMG C63
Update for the records:
The problem was a loose map sensor 2 harness - gray locking pin had broken and the harness had come loose/off enough to lose contact it appears. Once I re-secured it, the rough idle and poor driving were gone! Took it for a test drive and it is driving normally. I plan to get a new MAP sensor 2 harness to replace broken one.
(Side note, I had mentioned that that the JB4 Bluetooth module had failed. DMD, the company that makes the Bluetooth module for BMS, showed really great customer service and after a few emails back-and-forth where they responded very quickly, they sent out a new and improved version of the module which worked like a charm and was easier to install. This allowed me to connect the BMS phone app to the JB4 again and perform read/delete code functions.)
I do still have a lingering CEL and 2A0B map sensor code, even after deleting a few times. I plan to drive the car for a couple days and see if it is just a ghost code that goes away on its own.
If it does not go away or the symptoms resurface, I will update this thread. Otherwise you can assume it worked.
Edit / Update:
Code went away a day later, all good!
The problem was a loose map sensor 2 harness - gray locking pin had broken and the harness had come loose/off enough to lose contact it appears. Once I re-secured it, the rough idle and poor driving were gone! Took it for a test drive and it is driving normally. I plan to get a new MAP sensor 2 harness to replace broken one.
(Side note, I had mentioned that that the JB4 Bluetooth module had failed. DMD, the company that makes the Bluetooth module for BMS, showed really great customer service and after a few emails back-and-forth where they responded very quickly, they sent out a new and improved version of the module which worked like a charm and was easier to install. This allowed me to connect the BMS phone app to the JB4 again and perform read/delete code functions.)
I do still have a lingering CEL and 2A0B map sensor code, even after deleting a few times. I plan to drive the car for a couple days and see if it is just a ghost code that goes away on its own.
If it does not go away or the symptoms resurface, I will update this thread. Otherwise you can assume it worked.
Edit / Update:
Code went away a day later, all good!
Last edited by LessIsMore; May 4, 2021 at 09:17 PM.
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Junior Member
Joined: Feb 2019
Posts: 46
Likes: 13
From: Socal
2017 C63
What a timely update. I just ran into the issues with a bunch of codes and misfiring. I already checked the enclosure and board and it looked fine, so I resealed the edges with silicone. Once I reset the codes, the roughness went away, but I still retained the 2A0B code after cold start this morning. I'll check those connections and then give it some time to go away.
Newbie
Joined: Aug 2023
Posts: 1
Likes: 0
From: Melb,Australia
Mercedes Benz 2021 C63S
Update for the records:
The problem was a loose map sensor 2 harness - gray locking pin had broken and the harness had come loose/off enough to lose contact it appears. Once I re-secured it, the rough idle and poor driving were gone! Took it for a test drive and it is driving normally. I plan to get a new MAP sensor 2 harness to replace broken one.
(Side note, I had mentioned that that the JB4 Bluetooth module had failed. DMD, the company that makes the Bluetooth module for BMS, showed really great customer service and after a few emails back-and-forth where they responded very quickly, they sent out a new and improved version of the module which worked like a charm and was easier to install. This allowed me to connect the BMS phone app to the JB4 again and perform read/delete code functions.)
I do still have a lingering CEL and 2A0B map sensor code, even after deleting a few times. I plan to drive the car for a couple days and see if it is just a ghost code that goes away on its own.
If it does not go away or the symptoms resurface, I will update this thread. Otherwise you can assume it worked.
Edit / Update:
Code went away a day later, all good!
The problem was a loose map sensor 2 harness - gray locking pin had broken and the harness had come loose/off enough to lose contact it appears. Once I re-secured it, the rough idle and poor driving were gone! Took it for a test drive and it is driving normally. I plan to get a new MAP sensor 2 harness to replace broken one.
(Side note, I had mentioned that that the JB4 Bluetooth module had failed. DMD, the company that makes the Bluetooth module for BMS, showed really great customer service and after a few emails back-and-forth where they responded very quickly, they sent out a new and improved version of the module which worked like a charm and was easier to install. This allowed me to connect the BMS phone app to the JB4 again and perform read/delete code functions.)
I do still have a lingering CEL and 2A0B map sensor code, even after deleting a few times. I plan to drive the car for a couple days and see if it is just a ghost code that goes away on its own.
If it does not go away or the symptoms resurface, I will update this thread. Otherwise you can assume it worked.
Edit / Update:
Code went away a day later, all good!
