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I have a 2021 e350 sedan base. So last night I literally pull out of my drive way, drive maybe 5 mins and turn on this bumpy road. Immediate I feel the car start to shake and my check engine light comes on along with eco mode off. The car feels slow and funky, and after some research into this forum, I now recognize it as limp mode. Drive it back home limping and pray that the CEL disappears by dawn. No luck, in the morning the car was still limping and CEL is still on solid. Take it to the local parts shop and the OBD2 read pulls code P2187 "air-fuel mixture ratio is too lean" and P0191 "Fuel Rail Pressure Sensor Circuit “A” Range/Performance". I have done a fair bit of researching those so far but no definite answers.
To add to my misery, the car just hit 41k miles .
Had bought a at home OBD2 reader and pulled some more info of the triggering event that I am attaching here.
Anybody had a similar issue or any ideas what it could be?
I read through your freeze frame data.
Your HPFP seems perfectly well near 3000.Psi
Your Bk1 LTFT are perfectly good as well
Your power supply voltage is great as well
The ambient was 75F: easy mixture!
It all seems like nothing could be better... yet ECU bug checked into limp-mode cause of lean + pressure.
You've got an unusual glitch condition at 40kMi.
> MISSINGS....
What I miss is the low side fuel pressure
and Bk2 LTFT
along with a scan of all chassis modules.
> REMEDIATION....
You can try to reset this and see how it will last until Murphy shows up again.
You can through in a new MB rail sensor for good measure, literally - Yet nothing proves your fuel sensor's gone wild.
Having a wider chassis consideration will let you see if this is referred pain from tank fuel module, conveniently sharing same highspeed CAN-C.... anything can disrupt it as expected.
Don't through parts at this blindly unless you're desperate!!
> SCENARIO....
What I think is at work here is one of the electronically managed fuel pumps experienced a transient condition that freeked out the ECU mixture as withessed by BOTH FAULT CODES STRESSING THAT. Engine jerkiness was indeed low pressure...
There's a chance CAN-Bus is involved in disrupting one of the pressure controls...
We need more clues to further identify a patern. Pay attention to how and when this reproduces.
Of course hopefully it won't happen again on your watch...
🤞
Last edited by CaliBenzDriver; Nov 4, 2024 at 01:12 AM.
JR also note there may not be a bk2 here but some 4Cyl. inline are split in 2x distinct banks as if V6/8.
Bank count can be misleading...
+++ Yep OP states "2021 E350...."
the V6-3.5L has been upgraded to a 4-Cyl. turbo ??
Took the car to the dealer, per the service agent, the codes cleared out when they put the car into diagnostics and supposedly the limp mode is reverted. The shop doesn’t know why this happened but I suspect your theory is quite plausible. The agent did say that while on limp mode as he was pulling my car into the shop, he noticed rough idling so he wants to make extra sure that it’s not a true problem even though the engine is idling fine once the codes cleared. When I asked him how he was gonna do that, he said he’s gonna have the technician drive the car for a day or two and make sure no codes pop up.
Sounds like a weak explanation but I left the car with them for observation. What is slightly annoying me is how the shop didn’t do any further diagnostics once the codes cleared, rather they would just take joy rides in my car and see if the problem pops up again in a short period of time.
And yes 😂 the 2021 E350 was “upgraded” to the 4 cylinder turbo.
Thank you for all of your inputs! Not holding my breath on the dealership coming up with a diagnosis. I am just glad (so far) that it has not turned out to be a big issue. Can't really think of any other specifics that I can provide other than when this happened it was raining and moderately wet conditions on a road with ongoing paving. Other periodic issues include parking sensors and surround view camera being moody and temperamental, tail lights frying up (both, a year apart). There was one time when the steering wheel randomly locked up at moderate road speeds because the car thought there was no key fob within it. Luckily I was on a less traveled road and able to pull over safely. The car was fine like nothing happened after turning it off then on.
Wondering if anyone had experiences with the federally mandated warranty for emission related components (8 years, 80,000). It might be able to cover certain components if Murphy decides to show up later.
Last edited by rivinus.stenson; Nov 4, 2024 at 05:25 PM.
Thank you for all of your inputs! Not holding my breath on the dealership coming up with a diagnosis. I am just glad (so far) that it has not turned out to be a big issue. Can't really think of any other specifics that I can provide other than when this happened it was raining and moderately wet conditions on a road with ongoing paving. Other periodic issues include parking sensors and surround view camera being moody and temperamental, tail lights frying up (both, a year apart). There was one time when the steering wheel randomly locked up at moderate road speeds because the car thought there was no key fob within it. Luckily I was on a less traveled road and able to pull over safely. The car was fine like nothing happened after turning it off then on.
Wondering if anyone had experiences with the federally mandated warranty for emission related components (8 years, 80,000). It might be able to cover certain components if Murphy decides to show up later.
Well there, now we have got the collateral evidences we were missing.
You getting "the steering lock up while driving" is 90% chance related with engine hickups.
Nothing wrong with the engine fuel system!
It's the unstable networked computer modules having a cat-fight argument.
BTW, this explains why dealer don't always rush after the wrong clues.
This is an advanced fault mode. Your VIP CAN-C suffers from instabilities. That directly bugs out the fuel pressure control module.
You're not alone but you do have an hyper active case!!
For your safety, you may decide to seek immediate shop attention.
Based on your set of specifics, you can scan your whole chassis for disruptive modules and keep an eye on voltage while driving.
Last edited by CaliBenzDriver; Nov 4, 2024 at 05:49 PM.
Well there, now we have got the collateral evidences we were missing.
You getting "the steering lock up while driving" is 90% chance related with engine hickups.
Nothing wrong with the engine fuel system!
It's the unstable networked computer modules having a cat-fight argument.
BTW, this explains why dealer don't always rush after the wrong clues.
This is an advanced fault mode. Your VIP CAN-C suffers from instabilities. That directly bugs out the fuel pressure control module.
You're not alone but you do have an hyper active case!!
For your safety, you may decide to seek immediate shop attention.
Based on your set of specifics, you can scan your whole chassis for disruptive modules and keep an eye on voltage while driving.
I have tried to bring this to the shop's attention but all they have gotten back to me is "we will drive it some more" and "no current codes". How would I go about convincing the dealership about this? Also, how do I scan the whole chassis individually? My OBD reader that I have posted readings from does not have any other metrics other than those listed that it can measure.
I have tried to bring this to the shop's attention but all they have gotten back to me is "we will drive it some more" and "no current codes".
How would I go about convincing the dealership about this?
Also, how do I scan the whole chassis individually?
My OBD reader that I have posted readings from does not have any other metrics other than those listed that it can measure.
The dealer knows these cars inside out... there are gonna do only what they want to do regardless of your precise requests.
If you tell 'em your steering locked up while driving, you're guaranteed they will replace the perfectly good steering rack.
If you tell 'em your fuel pump had low output they will replace the tank pump plus control module.
Small chance they can hit the nail blindly with their expensive-parts canon.
A lot of good ppl around here recommend the "LAUNCH Co MB cReader Elite"... $150 or so on Amazon. It's very convenient to generate complete report with 100% coverage, datastream, some coding... a very nice deal!!
Your chassis has a pretty hyperactive chaos generator - These cars are built carefully - You have a chance to catch this issue.
Based on your previous inputs...
The 360° camera may be it, the soaked bumper radars are prime source of heavy chaos (no-crank)... of course steering and pump will never fix remote troubles - I call this referred pain much like a sciatica!
That's why you need a scanner for a broader view.
Last edited by CaliBenzDriver; Nov 4, 2024 at 06:45 PM.
The dealer knows these cars inside out... there are gonna do only what they want to do regardless of your precise requests.
If you tell 'em your steering locked up while driving, you're guaranteed they will replace the perfectly good steering rack.
If you tell 'em your fuel pump had low output they will replace the tank pump plus control module.
Small chance they can hit the nail blindly with their expensive-parts canon.
A lot of good ppl around here recommend the "LAUNCH Co MB cReader Elite"... $150 or so on Amazon. It's very convenient to generate complete report with 100% coverage, datastream, some coding... a very nice deal!!
Your chassis has a pretty hyperactive chaos generator - These cars are built carefully - You have a chance to catch this issue.
Based on your previous inputs...
The 360° camera may be it, the soaked bumper radars are prime source of heavy chaos (no-crank)... of course steering and pump will never fix remote troubles - I call this referred pain much like a sciatica!
That's why you need a scanner for a broader view.
I appreciate your valuable input. No codes popping up on multiple test drives per dealer. I think investing in the cReader elite you mentioned will be my next step when I get my car back!
Interesting you mentioned the soaked parking radar sensors… the parking system does freak out more often when it’s raining. Has been a constant issue since I acquired the vehicle.
I appreciate your valuable input. No codes popping up on multiple test drives per dealer. I think investing in the cReader elite you mentioned will be my next step when I get my car back!
Interesting you mentioned the soaked parking radar sensors… the parking system does freak out more often when it’s raining. Has been a constant issue since I acquired the vehicle.
There you go!!!
>> Act right now by requesting dealer replace the failed sensors and seal the leaky connectors with RTV sealant so repairs don't get wasted during winter.
>> Or save $1500... do it all yourself using scanner because Dealer will unlikely seal all your connectors... it's not included in the factory procedure.
This has high possibility (80% ballpark) to cause all your scary chaos by disrupting CAN-Bus.
Once done your MB will be the armored-tank, you thought you purchased minus the built-in weaknesses.
Last edited by CaliBenzDriver; Nov 5, 2024 at 01:43 PM.
Doubt the dealer will do anything about it since I have taken it to them multiple times for that issue in the past. Sounds like something I will have to tackle on my own!
For my understanding, can you explain how the sensors can be effecting the other modules?
Last edited by rivinus.stenson; Nov 5, 2024 at 01:49 PM.
Doubt the dealer will do anything about it since I have taken it to them multiple times for that issue in the past. Sounds like something I will have to tackle on my own!
For my understanding, can you explain how the sensors can be effecting the other modules?
modules are networked over separate segments but regardless are needed to work well.
When disrupted modules cause data traffic jams, much like on the road at rush hours. Priority traffic packet are impacted as well.
Bumper sensors, cameras have many interactions with unsuspected modules such as ESP or SCM... to read inputs for necessary computations.
Missing/bad sensors/modules = traffic jam/slow/delayed data through put with wasted bandwidth turn fast network into poor performance.
@BenzNinja : can you help sort defective modules to fix this ?
Last edited by CaliBenzDriver; Nov 8, 2024 at 06:05 AM.
modules are networked over separate segments but regardless are needed to work well.
When disrupted modules cause data traffic jams, much like on the road at rush hours. Priority traffic packet are impacted as well.
Bumper sensors, cameras have many interactions with unsuspected modules such as ESP or SCM... to read inputs for necessary computations.
Missing/bad sensors/modules = traffic jam/slow/delayed data through put with wasted bandwidth turn fast network into poor performance.
@BenzNinja : can you help sort defective modules to fix this ?
sure there is a whole bunch of things to try
from software change, up or downgrade to Xentry tests
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HELP: Code P2187 and P0191
