Calling all C400 Owners
Thread Starter
Member
Joined: Jul 2018
Posts: 132
Likes: 27
2017 Mercedes C63s
Calling all C400 Owners
Hello fellow C400 owners, I have an issue and I would like help from yall. So I got my C400 tuned by Eurofed Charlotte in November of 2019 and they did an ECU Tune Flash with DME stage 2. In January, I had a CEL on and the code was P0087, said "The Fuel pressure was too low," I had a certified shop test my HPFP since my local dealership would have charged me $300+ for diag. I cleared the code and it never came back on. Then yesterday as of October 1, I got another code related to the fuel pressure but it was P2539 which was "Low pressure fuel system sensor circuit." Also cleared it, never came back but I want to ask my fellow C400 owners, and hopefully some tuned C400s. Does anyone have this problem? I was told it could be the HPFP going bad and I was also told it has something to do with my tune. Either way, I will most likely get everything looked at, but I would like some feedback or get some ideas from you guys. Thanks~
Senior Member
Joined: Mar 2018
Posts: 323
Likes: 103
From: Central Florida
'15 C400 and '15 ML350
I have JB4 with fuel plug and aggressive map 6 on my C400. no fuel pump problems or CELs in the 2+yrs with piggyback.
I have heard from others that older firmware's would sometimes throw a low pressure issue.
Do you run E85? if so how much do you mix with 93?
Edit: most of the C400's I think frequent the C43/450 subforum more than the C300 one since we share the same motor and options for aftermarket with them. Might get more info there.
I have heard from others that older firmware's would sometimes throw a low pressure issue.
Do you run E85? if so how much do you mix with 93?
Edit: most of the C400's I think frequent the C43/450 subforum more than the C300 one since we share the same motor and options for aftermarket with them. Might get more info there.
Last edited by MatthewJ; Oct 2, 2020 at 10:48 AM.
Thread Starter
Member
Joined: Jul 2018
Posts: 132
Likes: 27
2017 Mercedes C63s
I have JB4 with fuel plug and aggressive map 6 on my C400. no fuel pump problems or CELs in the 2+yrs with piggyback.
I have heard from others that older firmware's would sometimes throw a low pressure issue.
Do you run E85? if so how much do you mix with 93?
Edit: most of the C400's I think frequent the C43/450 subforum more than the C300 one since we share the same motor and options for aftermarket with them. Might get more info there.
I have heard from others that older firmware's would sometimes throw a low pressure issue.
Do you run E85? if so how much do you mix with 93?
Edit: most of the C400's I think frequent the C43/450 subforum more than the C300 one since we share the same motor and options for aftermarket with them. Might get more info there.
I'm using 93-octane only cause its hard to get E-85 here.
