I just returned from a family vacation that my wife and I took. We drove the 2014 E350 from Birmingham, AL to Flint, Mi, and back. The problem started a few hours into the drive. First, we would get the Blind Spot Assist Inop error message and then later the turn signals would quit working. When we turned the engine off and back on, everything would work again.

I disabled the Blind Spot assist thinking that might help the turn signal issue, but it did not.

Any ideas?

Thanks,
Mark

 

​​​​​​Mark, glad your plans did not get scrambled by this genuine issue.

This shares the same cause as the battery yoyo: silently soft-crashed CAN networking courtesy of CGW.


> SIMPLE WORK AROUNDS:
-- Drive with HEADLIGHTS:ON
-- Chassis REBOOT twice a month.

Fix being to resolder defective networking modules to preserve CGW integrity.

Please scan your car for faults so we can see consequences with a silent cause.

 

Thanks CaliBenzDriver. I have done some research on the CGW and think it may need replacing. A couple of questions for you first:

1. What do you mean by "Chassis reboot twice a month"? I have never heard of a chassis reboot.
2. How does driving with headlights on serve as a work around?

Also, I did not find any faults using my scanner and I found that I could not connect to 1 or 2 of the modules. I suppose this also is a sign that the CGW is bad.

Thanks,
Mark

 

All good questions, Mark !


The reliable legacy voltage regulation has been morphed from an independent ALT into a fragile networked feature...

ALT is still producing 100% chassis power but is now digitally managed by the ECU over a serial COM's.

ECU request dynamic voltage output from VALEO ALT according to many parameters including battery status and engine load.

The ECU streams live battery Temp + Voltage + Current data from the R-SAM CAN-B through CGW on CAN-C. That's where chaos gets factored in.

The HELLA R-SAM controls the smart HYUNDAI battery mgt sensor to retrieve charge condition. These 3rd party modules work well!


> Great, then what's wrong ?
This brilliant BOSCH design is not fail-safe!

-- When the BOSCH ECU logic is unable to retrieve timely data, the ALT control begins to float wander uncontrollably.
A normally honest design would have self-diagnosis faults plus automatic watch-dog to peg 12.6V instead of a missing default value.
Bosch doing this is squarely ridiculous concerning because it's jacked in multiple levels.

-- 90Amps high charge + drain current damages many things with 1300.Watts heat (90A x 14.9V): both AGM Batts, ALT diodes rectifier, belt, strap all the way to LIMP-MODE crash of ECU/TCU: power loss at highway speed.

-- Under normal working conditions, this system charges both battery 100% with perfectly smooth small currents. Batteries are only charged and never drained while driving because ALT is always supplying voltage above 12.55V.


> MANUAL FAIL-SAFE REQUEST :
-1- "Headlights:ON" request the chassis voltage to stay above 13.7V without any room for error. This is a failsafe feature.

-2- Same as "opening driver door" while Parked commands 14.4V.


> ACTION PLAN B:
-- Replacing new BATT MAIN + AUX, ALT, F-SAM/CGW, R-SAM... SOLVES NOTHING because this is bad from factory ie. all new parts provide this engineered chaos.

These are experimental options...
-- The quickest way to lose the voltage chaos is to unplug ALT LIN.... done with this madness! At least some of it, TCU still affected.

-- My favorite: solder CAN-C Modules with poor connections to prevent soft-crashing CGW Gateway with junk traffic.

-- Float main battery with a CTEK charger while parked.


> CGW CENTER STAGE:
Actually BOSCH CGW is not the bad guy either!
It gets soft-crashed and only needs a reboot.

This module works 24x7 non-stop, always powered up to direct traffic to power manager Front-SAM.

The No1 CHASSIS TROUBLEMAKER IS THE BOSCH CROWNJEWEL ESP module that jams ALL CAN-C traffic.
The ESP causes soft-crash of the Bosch CGW/F-SAM that in turn causes poor performance of Bosch ECU/TCU team.

High chances this engineered chaos is implemented on many BOSCH chassis such as cars, heavy trucks, bus coaches.... with similar results. Spread the news to prevent drama.

I have personally been on two different tour coaches in USA where the drivers knew to restart the bus to clear this madness so they could safely drive 50ppl.

Disconnecting ALT LIN only cancels voltage chaos while driving. Drain while stopped still caused by soft-crashed CAN-B Modules (KeylessG, 4x DCU ,...)


++++ Rebooting chassis bi-monthly...
This helps CGW gateway track established connections well for a while.
I don't know simple ways to restart CGW/SAM module with scanner or fuse pull.

+++ BLIND SPOT ASSIST....
This fault is raised when the control module is unable to network with rear sensors on longer trips because of CGW jammed by crazy ESP !!
​​​​​​

++++ VOLTAGE DISPLAY WHILE DRIVING...

VEHICLE DATA.... VOLTAGE display

​​​​​​See before engine start.

 

I thought I would update this post. I took it to the dealer about a year ago without codes, so they did not fix it. They told me that next time it does it to bring it in without shutting it down. Well, I got the chance on a trip back from Chattanooga to Birmingham. Instead of coming home, I took it straight to the dealer. They diagnosed a bad module in the steering column. They are going to fix it this week.

 

Steering Column sounds like the SCM... sure it can benefit from properly working. You will notice the steering on freeway tracks straight and stable by itself from a better SCM.
🤞

 

I had an identical issue on my '13 ML. Replacing the steering column module fixed the problem. The labor is stupid easy, like a half hour. Part is about $600 at mbpartshaus.
The r&r procedure can be found by searching my posts from about 8 months ago.