Navion 24D CEL

[BlueGekko]

I don’t recall if it was this forum or another Winnie forum but approx a month ago I posted about a spontaneous Check Engine Light on my 2019 Navion 24D. When, after driving approx 350 miles, I finally got it to a dealer to diagnose it, it turned itself off. The MB dealer couldn’t explain it. I just finished watching a Lichtsinn RV YouTube video about winterizing the plumbing. The first thing the mechanic did was to disconnect the chassis battery. However, he warned to wait 15-20 minutes after turning the engine off before disconnecting the chassis battery. Apparently the onboard computer systems need that long to tidy up their circuits after shutting the engine off. He cautioned that not waiting that 15-20 minutes would result in a CEL code that MB would have to clear. Apparently they’ve seen it happen several times. I’ve found no mention of this wait time in my Navion handbook and no one mentioned it in response to my previous online query. Usually, if we aren’t planning another road trip after returning from one, I’ll disconnect the chassis battery as soon as I’ve extended the slide so that I don’t risk depletion by parasitic drains. It seems likely that this was the reason for my phantom CEL problem. Anyone else seen thus problem or can confirm the wait time issue?

[Winterbagoal]

Before I begin, I checked Winnebago's website under Owner Tools, Operator Manuals, and the 2019 Navion Owner's Manual points to the 2018 Owner's Manual. NO idea why. I tried the 2018 Navion and it points to the 2017, and the 2020 Navion points to the 2020 version. I could not find one for the 2019 Navion.
That said, there are comments in the Winnebago Navion manuals that I could find that had Notes for the use of the battery disconnect switch on or near pages 6-8 and 6-9 in the Electrical section like this...

"Chassis Battery Connector
The chassis battery connector is located to the
right of the accelerator pedal in the driver side
foot well.
NOTE: Ensure that the ignition key is in the Off
position and the key is removed, and wait
10 minutes before disconnecting."

So, Winnebago recommends waiting 10 minutes before disconnnecting the chassis battery at the accelerator pedal.

Likewise it is mentioned in my 2017 Mercedes-Benz Sprinter Operating Manual on pages 116-117 as such

"Battery isolating switch
Important safety notes
! Make sure that the key is in position 0 in the
ignition lock and that at least two minutes
have passed before removing or reconnecting
the battery main switch. You could otherwise
damage components of the electrical system."

So, Mercedes-Benz recommends at least 2 minutes before disconnecting.
Not what your service tech suggested, but it is mentioned.

This delay is mentioned in a couple of places in the manuals.

As for the "no mention in my previous online inquiry", you get what you pay for.
Not every problem necessarily has a eureka moment for forum members, nor are any of the info/advice/suggestions you get vetted by anyone. It's up to you to do your own due diligence.

[BlueGekko]

I seem to have missed those passages during my read of the manuals. You have to admit, though, that the WB owner’s manual isn’t easy to read. Still, there seems to be no mention in any of the manuals about the connection between insufficient disconnect wait time and the phantom CEL. That correlation is really the reason for my most recent post and to provide what I thought was new information to the forum. Finally, I wasn’t being critical of anyone’s non-response to my previous query about the CEL. The non-response indicated to me that it was likely that no one knew why I had a phantom CEL. Thanks for chiming in, Winterbagoal. Appreciate your research and response.

[Winterbagoal]

Originally Posted by BlueGekko

I seem to have missed those passages during my read of the manuals. You have to admit, though, that the WB owner’s manual isn’t easy to read. Still, there seems to be no mention in any of the manuals about the connection between insufficient disconnect wait time and the phantom CEL. That correlation is really the reason for my most recent post and to provide what I thought was new information to the forum. Finally, I wasn’t being critical of anyone’s non-response to my previous query about the CEL. The non-response indicated to me that it was likely that no one knew why I had a phantom CEL. Thanks for chiming in, Winterbagoal. Appreciate your research and response.

I remember the CEL incident and the MB tech wasn't really able to provide a reason or solution. Just a NTF (no trouble found) after the 500 mile drive (which may have cleared the CEL cause, as I suggested in that thread. Sometimes a long drive will clear some fault codes, if they are neither critical, nor cause LHM.
As for the research and response part?
It's what I do.

[creativepart]

Originally Posted by BlueGekko

I don’t recall if it was this forum or another Winnie forum but approx a month ago I posted about a spontaneous Check Engine Light on my 2019 Navion 24D.

Yep, you posted about that here a little over 2-weeks ago:

https://www.winnieowners.com/forums/...ce-358541.html

You can always find your previous posts by clicking on your username in the upper right hand side of the screen. Then click on "Statistics" tab on the new page that opens and select either "Find all posts by [your username]" or "Find all threads started by [your username]."

[BlueGekko]

Good to have a fact checker and solution finder on the site, Al. And thanks, CreativePart. Had no idea I could find my previous posts.

[Winterbagoal]

Originally Posted by BlueGekko

Good to have a fact checker and solution finder on the site, Al. And thanks, CreativePart. Had no idea I could find my previous posts.

That's how I found it.