HELP : 2006 R-Class Electrical/Short Issues?

[NewR350]

Hi - recently purchased a new 2006 R350 from a dealer. After only having the car for 2 days, the vehicle's dashboard and multifunction display lit up light a video game, and completely shut down the car (no limp mode):

All the dashboard lights lit up:
- yellow exclamation point light
- orange brake light
- yellow ABS light

Multifunction display cycled thru errors:
- Drive to workshop without changing gear
- Visit Workshop
- ESP Display malfunction/Visit Workshop
- Run Flat Indicator unavailable
- Speedtronic inoperative

Luckily was able to pull over and park the car. But car would not shift into gear and was stuck. Called RA, MB tech tried to disconnect/reconnect battery, removed/reinserted fuse, and even tried to run a diagnostics via his computer - but he could not connect to primary command center. Therefore he could not shift the car into Neutral, so the car had be dragged onto the flatbed with the plates.

In any case, local MB dealer ended up determining that the Airmatic Control unit had shorted, and basically replaced the module. The work was later double checked by the selling dealer, and we were told that the vehicle was fine.

But just over a week later, the car lit up again and got stuck in park. Sent the car back to the dealer again, and after more analysis, they state that the Z connector plug was not properly grounded to the main wiring harness. They claim that this will "fix" the problem.

Any idea if this is the magic bullet that will actually correct this issue?????

Appreciate any guidance to validate that this problem is truly resolved.

- Owner of R350 for 1 month, already in shop for 20 days....

[ILUVMILS]

If I saw the actual SDS "Short-Test" I could probably offer more help, but from what you say it sounds like either the battery voltage dropped, or the Engine CAN ( a network for drive-train related computers) went down. I'm not sure what the "Z connector plug" is about. MB's use the designation "Z" on wiring diagrams to indicate a circuit that feeds power/ground to multiple devices. They're all numbered, but you don't say which one it is.

Your ABS, ESP, Cruise Control, etc. all use the same network to communicate with each other. If this network goes down lots of weird things can happen.

Same thing goes for low voltage. The "Drive to workshop without changing gear" message was trying to tell you something. Don't shift into "PARK"!!! Apparently, you found this out. If the network is down, or the battery voltage is too low, you won't be able to shift back out of "PARK". Your R-Class has an auxiliary battery whose sole purpose is to allow you to engage "PARK" (for obvious safety reasons) in the event the main battery is flat.

If you could provide more details about the actual repair maybe we could narrow it down a bit more.

[NewR350]

Thanks for the insight. It is quite possible that I missed writing down that particular error message, as it cycled thru so many, so quickly.

I don't have the exact details about the resulting repair yet, since the vehicle is still being tested by the dealer. I probably messed up assessment of the solution, so I can post more details once I pick up the "newly repaired" car.

BTW - at the time of the error messages and subsequent shutdown, the vehicle started to behave erraticly, seeming to lose power and experienced jerky shifting. Basically pulled over because was traveling in the middle of a busy road, in an unfamilar area.... not ideal.

[NewR350]

The tech found a bad connection at connector Z204/4 under right front rug. That apparently was the cause of the engine CAN short.

It's only been a week, but so far so good....

[ILUVMILS]

Among other things, Z204/4 supplies ground to the Engine CAN voltage distributor. This explains the numerous CAN problems you experienced. It sounds like they nailed it.

[STX-MBZ]

I am having the same issue with my 2011 ML350 4Matic. Where can i locate the z204/4 connector?

[ILUVMILS]

Under the carpet in the RF footwell......

[tyduckycody]

I am having similar issues and want to check the z connector. I have the carpet taken out of the passenger side of my 2007 r350 and there's a million wires. Could I be given more of a clue as to where that connector is?