MBS no start

[natfinsness]

I have a 2019 Dynamax Isata3 on a 2018 MBS chassis. Approximately 2500 miles. Twice in the last week, the truck will not start. It turns on, all the lights come on, but no starter action. Checked everything I could think of including truck being in park and neutral, jumping to the camper batteries, still no start. Then after a few minutes, it starts right up like there was never a problem.
Anybody else have this problem???

[milkman55]

This may be simplistic, but you are waiting for the diesel glow plug light to go out before trying to start?

[JLeising]

Here is a link to an older post about a similar problem:
http://www.forestriverforums.com/for...des-99476.html

[KatanaPilot]

We have a 2015 Forester MBS. Occasionally it won’t turn over. I pull the key out and reinsert or switch to the other key and it starts right up.

I did have one MB service advisor tell me he had seen the same thing several times but only on MBS chassis with RV coaches.

His theory was some interference with the transponder in the key that communicates with the ECU - part of the anti-theft system.

There was no fix as MB didn’t think there was an issue. Doubt this helps but at least you aren’t crazy.

[mjbenedict]

Look for loose negative on battery and chassis, do the same with the starter and any jumpers from chassis to engine block. Make sure to check positive as well. This is if you are hearing the click but no turn over. If turning over that’s another issue.

[natfinsness]

Thanks. I am waiting for glow plug light to go off. Checked battery connections.
Not even a solenoid click when it happens. I am also thinking the sensor in keys not mating with ECU. Tried both keys. I will report back if I find it.

[KatanaPilot]

Originally Posted by natfinsness

Thanks. I am waiting for glow plug light to go off. Checked battery connections.
Not even a solenoid click when it happens. I am also thinking the sensor in keys not mating with ECU. Tried both keys. I will report back if I find it.

Another thing that usually works for me is to remove the key, rotate it 180 degrees and reinsert. It starts right away.


Like you - no clicks, no dimming of lights (like a weak battery or loose connections) - nothing. I can't explain it, but it happens to me too. The ECU has to recognize the chip in the key (I assume it's RFID technology) and if it does, it enables the starter circuit. Not recognizing the key is strange, but would explain the symptoms we see.

[bclemens]

I have only seen this a couple of times...but it can be frustrating as it is not easy to replicate. I agree that some sort of key matching thing seems to be at the core, but when it goes to the dealership it just starts up every time. (of course).

I know on the new chassis, they have a slot down below to pair the key again. Not sure if that was some new thing they established to counter issues like this, or similar..I just know its there and was not before.

[kenandterry]

Isn’t it push button start on the new 2019 Mercedes cutaway chassis?

[bclemens]

yes

[Barch]

I have also had this issue. Fortunately, after a couple of tries. i.e. remove the key, re-insert, etc, it has always started. I'll keep my fingers crossed and try the 180 degree maneuver as needed.. Thanks for the info.

[bclemens]

Originally Posted by Barch

I have also had this issue. Fortunately, after a couple of tries. i.e. remove the key, re-insert, etc, it has always started. I'll keep my fingers crossed and try the 180 degree maneuver as needed.. Thanks for the info.

So it’s just like a USB plug. Plug in, doesn’t fit. Turn over, doesn’t fit. Turn back over, finally fits. I’m sure that happened every single time to Steve Jobs....thus the lightning connector. Can’t wait until it’s allllll USB-C

[Delco Bobby]

Thank you, thank you, thank you. I thought I was the only one fighting the USB WAR.

BTW, I had a Chevy that wouldn't always recognize the chip in the key.

Originally Posted by bclemens

So it’s just like a USB plug. Plug in, doesn’t fit. Turn over, doesn’t fit. Turn back over, finally fits. I’m sure that happened every single time to Steve Jobs....thus the lightning connector. Can’t wait until it’s allllll USB-C

[van_fl]

https://sprinter-source.com/forum/sh...ighlight=cable

[natfinsness]

It is happening a lot more now. Just got a runaround from warranty people...it appears the warranty company, Coach Net no longer covers Forest River as of 2020.
I would like to take to. MBS dealer to fix. Based on a lot of research it is likely a neutral safety switch, which requires replacement of part of transmission.
Brian...will FR cover if I take to MBS dealer?

[bclemens]

No, if it is not starting that is a Mercedes issue and is covered by their warranty.

Just heard another story today. Some module is overheating. So when you take it somewhere, it won’t start, but if you fire it up cold it will. Not until it cools back down again will it start. Again, Mercedes issues and best served by a Mercedes dealer.

Ps. Coacnet is just a road side assistance company. And we do have another that has replaced them. But Mercedes has their own roadside as well.

[van_fl]

Not all MB dealers are certified to work on Sprinters, make sure where you take it. Call the number in the owners hand book and they will tell you the nearest Sprinter dealer. Sprinters are a finicky beast. But I loved my 2010 and had about 90,000 miles in 4 years with it when I turned it in for the I5.

[natfinsness]

Brought it to MB dealer in Daytona Beach last week. They were great...tried to diagnose, but of course, the issue would not happen while truck was there. They replaced starter...were confident it was that or loose ground and all grounds looked sound.
The no start happened again yesterday after driving for an hour...no warning lights, no click or sound. Then it started after cooling for 30 minutes.

[bclemens]

This is now the 2nd time that I have heard of this. In the first case....some tech poured water on some module, (PCM Module) because he said it was overheating? I am trying to dig into that. Just a guess at this point, but beats them just replacing parts blindly.

[bclemens]

Originally Posted by natfinsness

I have a 2019 Dynamax Isata3 on a 2018 MBS chassis. Approximately 2500 miles. Twice in the last week, the truck will not start. It turns on, all the lights come on, but no starter action. Checked everything I could think of including truck being in park and neutral, jumping to the camper batteries, still no start. Then after a few minutes, it starts right up like there was never a problem.
Anybody else have this problem???

Can you PM me the last 6 of your VIN? I'd like to escalate this to Mercedes.