N7legion

2014 E350. Havent driven my car in some time. Just finished replacing the brake lines and hoses, rotors/pads, air filters, and plugs. When test driving the CEL came on. Hit the highway and then loss of throttle, "pre-safe inoperable see owners manual", esc lights came on.
I've seen similar posts where it was suggested that it could be the pedal or aux battery. I changed main battery last year and aux battery about 2-3 years ago.
Was going to get it scanned for codes but dreading driving the car as it's happened about 5 times in about an hour. Most likely have to tow. Guess I'll have to invest in an diagnostic tool.
Any thoughts as to source of problem?

Sunnyslope48

https://mbworld.org/forums/e-class-w...operative.html Post # 56 may have at least part of your solution

N7legion

I'll give it a try. If it turns out I'll like his wife I will be surrendering my license.

CaliBenzDriver

That is a pretty interesting thread to read.
I'll side with post #61 that points at front RADAR Modules as the source of Pre-Safe errors. I became familiar with this on my MY'14 that matches OP's year.

The seatbelt pre-tensioners could be prime suspect for these errors if Distronic was not also pointed out... best way to find out is to scan the car for clues.

Here the OP has no reference to "Distronic warnings" but reports "loss of throttle" on the highway... actual limp-mode?


++++ TSB DTC# C10C700 : "Collision Prevention Assist Functions are Restricted"

>>> Here is the public link to this fix

Mercedes-Benz TSB LI30.30-P-059421 reads:

"...The control unit 'COLLISION PREVENTION ASSIST' has a malfunction because the radar sensor is maladjusted...."

🙂

Senecat

Scan car.

Disable that stupid pre-safe nanny control crap-not the contributor to power loss

ESC is gonna be an ABS sensor or related because you just fcked one of them up while you did the brakes-the contributor to power loss

Arrie

I agree, one bad wheel speed sensor will do all those errors. Need to scan for codes with scanner that reads inside different modules to know which one it is. Just a generic OBD II scanner for emissions will not suffice.

I have iCarsoft II scanner that is one of the lower cost ones, but there are other better scanners I believe at around the same or slightly higher price.

My scanner said the front left wheel speed sensor is bad in several modules and replacing that sensor fixed it all. I started the thread "Christmas tree lit up" for it.

Easy job, sensor was around $150 from the dealer if I recall correctly. I would not use third party part for this one.

P.S. Forgot to mention this happened with my S550, but I think it is built the same way as E-Class for this part.

KEY08

Agree with Senecat and Arrie. You must have damaged the sensor by accident

N7legion

Ran a diagnostic and got the following codes

Can anyone make sense of these codes?
​codes.Do I need to replace the pedal? 24hrs after my first post, the moment I touch the accelerator pedal the warning lights come on.

Arrie

Well, based on this perhaps it is not the wheel speed sensor though that caused almost all lights to come on in my car. Your error codes do not mention speed sensor anywhere so it points to your gas pedal but how would that cause an issue with the other items, like with the evap. system pressure switch?

Multiple items failing at the same time would be a massive coincidence so it did not happen. Something that is common for these items/issues is what failed and is causing error codes for them all.

But, for the heck of it, read what each speed sensor reads when driving... also you could read what the gas pedal sends out when you press it. Should not need to drive for this.

N7legion

the other codes are older and not letting me clear them out. Also car won't really move now. Limp mode is now more like hahaha you really think I'm going to move mode.

CaliBenzDriver

I think the gas pedal fault is a bit of red herring on this MY'14...

• CHARGE batteries
• disconnect battery 5mn to reset car
• Clear all DTC with scanner
• Test drive less than 20mn

If it is truly a defective pedal sensor (or the harness female pins to sensor) the pedal DTC should pop up shortly before the ECU gets glitchy

pierrejoliat

You might also try a gas pedal reset procedure after the battery re-connect. I don't recall the exact procedure at the moment, but it's here on the forum. Just my personal experience, but it seems most of these glitches can be reset or go away, new parts not always needed. I do recall a guy who did this reset procedure and it worked, another kept resetting it every two days and he eventually replaced the accelerator pedal assembly for a permanent fix.

N7legion

Thanks I'll give that a try. If not I'll just order from dealer.

pierrejoliat

First try;

FCP Euro
Mercedespartscenter.com

Might be more economical than the dealer, Try reset first, and as Calibenz says, check and clean plug and harness connections/ reset sequence before replacing parts?

CaliBenzDriver

Some module DTC's seem hard to clear at once from the main menu of these scanners... try to navigate into each individual module and clear from there. Then back out of the module, up into main menu.
This is really a scanner limitation (bug), not the car network being stubborn.


TROUBLESHOOTING 101:
I totally subscribe 100% to "go with the obvious first" when possible. Here we have a spread of faults pointing to a glitch.

Sometimes you get lucky and sometimes you replace parts then wonder why it doesn't work... It's better to troubleshoot up front.

Poke around before ordering an APP that may require SCN.

​​​​​​

N7legion

Ok so tried the reset, and seems to have worked. Took the car out for a test drive and everything ok . I park, turn the car off, restart and press the accelerator and back into limp mode. Checked the connector to the pedal. Clean and nothing out of the ordinary. Think at this point I'm gonna bite the bullet and buy the pedal. Have a connect through a body shop, gonna try and get at discounted price from dealer, if not FCP Euro it is.

N7legion

Update:
Changed the pedal, no change. Message still pops up. Checked the ground points I worked near, found one was corroded. Cleaned but still getting the DTC. Checked all fuses and none are fried. Trying a reset by disconnecting the battery. Hoping for the best.

CaliBenzDriver

Well now you have the most up to date version of APP it's a good thing going forward.

I'll keep this short:
Ensuring you have good starting and running voltages available will help a long way but it's not the cure.

Indulging in "Charge and Resets" can get you effective but temporary relief from goofy ECU/SAMs.
Consider fixing the bad GROUNDS points from front to back.

N7legion

Which ground point could be causing this issue in particular? Nothing else is giving off a DTC.

CaliBenzDriver

​​​​​​What's triggering these DTC's is the ECU glitching on low voltage transients.

Recently I had a look at the APP diagram. It's a dual independent circuit, not directly grounded. One circuit goes up while the other one goes down, very much like the throttle body control circuit. When APP opposite signals are found to be mismatched, ECU pulls a limp-mode to prevent uncontrolled rpm.

PreSafe, Pedal, EVAP.... all these faults are not individually significant here. I wish I could simply help you with a TSB repair or one specific ground screw... but this is spread out issue.

We have a dedicated thread for GND bounty hunting... that may help guide you.

All (ECU) grounds need to be equally good. ECU uses half dozen or more GND between engine screws and body posts.

Different GND points affect different ECU circuits. Instead of trying to figure which is what without an internal ECU schematic... I went for an ALL Inclusive quest.

There are 2x published GND's in driver footwell... I am still missing the 2nd one that may require my driver seat to fly out...

I used to get your exact set of errors (PreSafe, APP...) I have not had it in the past 25kMi.
🤞

juanmor40

Let us say there are 10 grnd points {there are more) 1 is already corroded. What is the chance that is the only one corroded? Very low, right?

If by any chance the next one you clean fixes the problem, will you stop cleaning them immediately and move on? Or clean as many as possible?

N7legion

So not sure if this is related...but I went back to double check the ground I had cleaned. As I was about to put liner back on I noticed grease on my hands. Look around and found this.




obviously recent. Grease all over the inside of the wheel. I'm assuming that maybe the sensor is noticing something. The axle boot is intact and all the control arms are new. Could it be leaking out of the edge of the axle boot or is this from the bearing?

juanmor40

My guess, axle boot. You may have moved the boot during your suspension work, and it is not tight as it looks.

N7legion

could that be the reason for the original problem and the dtc I'm getting?
and what's the fix to this. New axle?

CaliBenzDriver

yep, the only thing that can spread grease all around is something spinning, not a ball joint but AXLE BOOT.

Whomever replaced your new lower arms cause that weakness to surface.

Axle is now low on grease while your caliper and inner brake pads are coated.


greased up brake parts

Wipe excess grease and spray brake cleaner to finish degreasing all this mess