OldPizza

So I was driving down the road, found an open stretch and decided to gun it.
It kicked down to a lower gear and was pulling hard but then it felt like it hit a wall, almost like some sort of limiter and wouldn't let me accelerate any faster.
It appears to happen under WOT and seems to trigger at ~70 MPH.
Then the "ESP Visit Workshop" light came on, it turns off the supercharger and I now have some codes...

7201: The CAN communication if the engine control module is faulty
7211: The CAN communication if the engine control module is faulty
531A: The CAN message from the control module motor electronics is invalid or implausible

The car runs fine, idles great and still pulls/activates the super charger without any issue after I turn it off and back on.
But I'm able to recreate the issue by going WOT up to 70 MPH.

I did just have the alignment done and some new tires(same tire/wheel size).
I've tried the "ESP Reset" by going lock to lock etc. And that did not seem to help.
I know its not the super charger pump because I put a brand new Bosch 010 pump in it ~1000 miles ago.

Sounds like it could be a speed sensor?
Has anyone else had a similar experience or know what the issue may be?

OldPizza

I also noticed the car has the code:
P207c: Supercharger mechanical Fault

Which appears to go away after a restart of the cat but comes up when the ESP message comes on.

oneslow55

who tuned it?

OldPizza

Tony from RaceIQ tuned it. I sent him an email today asking if he had any ideas.

GinDistiller

Are those codes from the ESP/Suspension module or the ecm? Or I guess I should ask if you're scanning with an OBD reader or a Mercedes-specific tool.

CAN communication codes can be common, sometimes due to past battery issues or who knows what, and could be old so I'd clear those and see if they return.

OldPizza

I used an iCarsoft MB II to pull the codes...
The codes I posted were "Current and Stored" vs just stored.
Once I restarted the car though they went to a "stored" state but I could bring them "current" again after I went WOT in a lower gear.

This code was from the ECM:
P207c: Supercharger mechanical Fault

And these codes were from the ESP module
7201: The CAN communication if the engine control module is faulty
7211: The CAN communication if the engine control module is faulty
531A: The CAN message from the control module motor electronics is invalid or implausible

I noticed today if I just pulled some normal OBD II DTCs I got this code:
P0638: Throttle Actuator Control Range/Performance Bank 1

GinDistiller

Stock throttle body? And what mods do you have?

OldPizza

Yes, stock throttle body.
The only mod that RaceIQ did not tune to is the 3" intake kit... I guess it is possible that the car is getting more air than expected?

Mods:
77mm UPD SC Pulley
VRP Belt Wrap Kit
550cc Injectors
VRP 3" Intake Kit
PLM XL Heat Exchanger
Split Cooling
RaceIQ Tune

Repairs/New Parts(all done over 1000 miles ago):
010 Bosch Pump
IAT Sensor
MAP Sensor
Crank Sensor
New Spark Plugs

GinDistiller

You've got pretty much the same mods as me, minus the intake, I'm also tuned by Tony.

When you did MAP sensor, did you use a Genuine Mercedes part, and did you remove the SC to do it or scrape your hand and do it in the car?

OldPizza

I used genuine Mercedes parts. Basically turned my hand into swiss cheese and left the SC in the car.
It wasn't easy but it was totally doable with enough bendy extensions.

OldPizza

I removed the throttle body today to clean it, it had some gunk in it. Also disconnected it and cleaned all of the connections just in case...
Someone suggested that I unplug the batteries and leave the car overnight so I'll do that and see if it fixes anything.

GinDistiller

Haha yeah I feel you, that MAP replacement is a pain! But good that you didn't have the SC off since I would hope that would reduce the chances of a vacuum leak. However- if it persists you may want to do a smoke test as that throttle code comes up for people who have had issues with vacuum leaks or larger throttle bodies.

Good call on a battery reset, it will reset the TB stops too when you key on after doing that.

Other than that - I'd use the graphical OBD stream on your MBII to datalog (unless you have a proper datalogger) and see is anything is amiss. And I can almost guarantee you Tony will ask if you can datalog with a wideband to make sure there aren't fueling issues with the tune

OldPizza

Thanks for the input!
I'm hoping it will be an easy fix. I did so some data stream analysis earlier today to see if anything looked off.. Everything appeared to be okay.

The VRP intake kit is kind of junk, it was missing 2 hose clamps and they make you buy your own silicone coupler so it will work with the stock throttle body... Which they don't tell you beforehand... So I'm wondering if there were some leaks in the intake that was allowing for extra air during high RPM/boost situations. I'll slap the 3" coupler and missing hose clamps on the intake tomorrow. Hopefully that along with the cleaning/reset of the throttle body it will clear up my issue.

Slider

I have the same mods except wih a 76mm and minus the intake kit, but yeah, a leak can definitely cause serious problems.

OldPizza

Update:
I bolted the cleaned throttle body back up to the SC.
I fixed the connections on my intake and made sure they were sealing properly.
Plugged both batteries back in and took the car for a test drive.

Made sure to drive it nicely until it was at operating temperatures.

The first pull felt fine but the subsequent pull felt like it didn't want to shift to the next gear once it reached the redline...
Then that is when the SC cut off and the ESP lights came on/wouldn't let me accelerate anymore.

My error code for the throttle body is gone, must have been dirty throttle body or connector.
However I still have these codes:
This code was from the ECM:
P207c: Supercharger mechanical Fault

And these codes were from the ESP module
7201: The CAN communication if the engine control module is faulty
7211: The CAN communication if the engine control module is faulty
531A: The CAN message from the control module motor electronics is invalid or implausible

And I noticed one more in the TCM:
P2520: The feedback through the transmission protection is not maintained.

So now I'm wondering if I have a bad conductor plate or leaky electrical connector...
I have noticed lately that my shifts have felt really sloppy/slow and clunky just driving around town.
And during my tests above it felt like the transmission didn't want to shift out of 2nd/3rd when I'd hit the "brick wall".

Is it possible it is time to replace the conductor plate, electrical connector and do a transmission flush?
I have this kit, I just haven't gotten around to doing it yet as part of my preventative maintenance...
https://www.fcpeuro.com/products/mer...on-service-kit

GinDistiller

Yeah if you have those parts already I'd say it would be good to tackle regardless. Do you have the dipstick as well? Even a slightly low atf level can cause weird issues with shifting.

I'd also take 5 minutes and pull the passenger footwell floorboard back, 3 10mm plastic nuts and look at the tcu and harness back there for fluid intrusion. If you have that then you definitely need to do the transmission plug (and clean the TCU as well). The ESP module is mounted right next to it, I haven't heard of fluid getting in those too but takes just a minute to check.

So, bummer it came back, but good it codes immediately as that should make tracing this easier (vs an intermittent issue). Keep us posted!

OldPizza

So I replaced the conductor plate and cleaned the electrical connector on the transmission.
No more TCM codes!

BUT I'm still getting the odd limp mode behavior...
Car drives great as long as I'm not on it 100%. Once I go WOT and hit about 70 - 80 MPH you can feel it cut the supercharger then the ESP light comes on and I get the following codes:

This code was from the ECM:
P207C: Supercharger mechanical Fault (P0660)

And these codes were from the ESP module
7201: The CAN communication if the engine control module is faulty
7211: The CAN communication if the engine control module is faulty
531A: The CAN message from the control module motor electronics is invalid or implausible


The ESP codes will clear(stores) with just a simple restart of the car. The car also leaves limp mode and lets me use the supercharger again.
However the ECM codes stay current and stored...

I ran some diagnostics, clutch on S/C engages fine with star... The intercooler pump is working fine...
I'm sort of at a loss right now.

g300d

Hi, did you ever get this sorted? I'm going through the same thing.

OldPizza

​​​​​​

Yes, it ended up being the aftermarket VRP intake.
The silicone coupler at the end that mates up to the radiator was closing itself during boost and causing the issues. I removed the silicone coupler from the end and it fixed my problem.

g300d

Thanks for coming back and posting your solution!

Could you happen to give me an idea of your troubleshooting process to narrow it down to that?

I will check the intake boots but car is stock there so it might not be that.

Current mods are a smaller supercharger pulley, larger water cooler, and upgraded Bosch coolant pump, and a stage 2 tune over that, all from Eurocharged, if thats relevant.

OldPizza

Looking at your setup I doubt anything caused that. Unless you have a cooling issue.
Are you getting the same codes I did?

My process was LOTS AND LOTS of Google searches, then replacing common failure parts (IAT sensor, conductor plate) and then I started removing modifications from my car in the order I added them.
Did you get a STAR diagnostic report yet?

This was the post I made surrounding the intake issue:
https://mbworld.org/forums/w211-amg/...kit-users.html

g300d

Yup, exact same codes and symptoms as you, minus the transmission codes.

I've been doing lots and lots of Google searches too without much luck. Your thread is probably the most detailed I've found.

no STAR report yet, I read my codes via LAUNCH. Will get one and see if any additional info comes up.

Thanks for the additional link, will check it out!

Amir_AMG

When first reading your thread I thought it was the accelerator pedal...at least on my sl55 anytime I would go WOT car would go into limp mode(complete loss of power, ESP light on)

glad you got it sorted out

g300d

I've seen a few threads referencing the accelerator pedal with these symptoms too. But usually a scan shows codes for the pedal. Wish my problem was as straightforward!

g300d

Found the problem with mine, no boost because the engine spit out its supercharger belt. Stupid me for not seeing it, a friend of mine noticed when he looked under the hood while we were talking about it.

I swear I looked at the belt previously and it was still wrapped around the SC pulley then. When my friend looked yesterday, belt was already loose and pushing up.

So I put the belt back on and had boost for the afternoon, felt slightly down though. Had total loss of boost again with the ESP warning this morning and looking underhood shows the crank supercharger pulley decided to divorce itself from the crank pulley hub. The rubber damper was shredded.

Whats are people using nowadays for crank pulleys, OEM? Or are there any upgraded ones worth considering? I'll be doing the SC belt too, any suggestions for that? The back of the belt looked pretty smeared so considering a belt wrap kit too, who's the go-to for that?