FBH The end of the SAGA ?

[Arctic]

Hi SteveN
running on standard diesel, but have thought of using red diesel which is cheaper, not that it uses much, runs for about three hours on 250ml never really tested for much longer but will do this winter

[DelSelDi]

Hello everybody
My name is Robert, and i have problem with my PCB and you are my last hance to help.

Please, can anyone read the markings from the marked element? Mine was damaged from the temperature and now I do not know what it was and I can not find the diagram anywhere. Do any of you have a complete schematic of this board and, for example, could send it via e-mail?

The most important thing for me is to read the marking from the selected element

Can anyone help?
this element

[macafee2]

Originally Posted by DelSelDi

Hello everybody
My name is Robert, and i have problem with my PCB and you are my last hance to help.

Please, can anyone read the markings from the marked element? Mine was damaged from the temperature and now I do not know what it was and I can not find the diagram anywhere. Do any of you have a complete schematic of this board and, for example, could send it via e-mail?

The most important thing for me is to read the marking from the selected element

Can anyone help?
this element

Search the forum for the names Trebor or Devilish, send either one of them a message and they may be able to help you

macafee2

[DelSelDi]

Thank you for your suggestion in such a short time, I will search, and I hope they will because I have no idea where i find information about this element

[cosmin]

That is a double reversed diode, like in the picture i attached.

[DelSelDi]

Cosmin, thank you for this information, this knowledge helped me

[kokamagi]

Hi Mike, guys!
I have been directed here from the fullfatrr forum and read through all the threads by FrenchMike and HarryM1BYT regarding FBH.
It is hands down THE BEST place for FBH knowledge, especially PCB.
Only sad thing is that I can't see any attachments on Mike's post. Can't figure out why, I can see the attachments of all the other users.

Let's get on the subject now - sorry it's wrong make care, but it still is a Webasto.

I have a 2011 L322 Range Rover 4.4TDV8 and the FBH has had SEEMINGLY a circulation pump problem since last winter.
FBH model is Webasto Thermo Top C 9006157C / 65850M
It only runs for a couple of minutes and then turns off, sometimes the fuel pump starts clicking, and FBH fan speed increases, but most of the times not. So one might say it is intermittent.

So last winter I tested the pump - It had the correct resistance of 10kOhm and also ran well when applied 12V.
I even tried another good pump on it and still the same.
Also measured the voltage drop while FBH running and it was always OK (never under 12V), just to be sure, I put in a new Bosch AGM battery and the issue still persists, I am pretty certain that the problem lies in PCB.

Also did the "FrenchMike test" -
I started the FBH with the remote control while the car was locked and in sleep.
After 2-3 seconds it stopped for 1-2 seconds and ran until it stopped at about 2:02.
At 2:05 it started running again until it finally stopped at about 4:07.
But the HVAC blower kept going and the indicator LED blinked for over 10 minutes.
When I got to the car 23 minutes after the initial start of the test, all was still.
As I opened the door, HVAC blower instantly started blowing, about 20 seconds later FBH also started running and it ran again for about a couple of seconds over 2 minutes, then it stopped for good.
So my result wasn't exactly as described in the test, but there are similarities.

Can it be the glow plug? It tested fine with WTT, but haven't measured it directly.
If so why is it showing only circ. pump fault?
It looks to me that it's PCB fault most probably. And as it is intermittent (although it works and produces heat for a few minutes something like 2 times out of 100 ), I wonder if it might be a bad solder joint not a resistor etc.?

It always throws a fault B12A6-15 under the HVAC module - Auxiliary heater water pump - General electrical failure - circuit short to battery or open. For some reason I can't get to the FBH module, it just isn't on the list, but I know others have it.
Webasto WTT software shows 2 faults - 0E/08 Communication failure on customer specific bus. And also 03/04 Circulating pump interruption. It had a very poor connection with WTT, always cutting out, protocol saying things like: "Wrong echo received!", "Invalid message length!", "Diagnosis adapter is not connected!", "Checksum failure!" and "Timeout!"
Anyway, I could run tests on all the components except the circulation pump - as soon as I tried to start it, WTT lost connection, and some of the times as soon as I reconnected, the pump started working until I commanded it to stop. And when I finally finished diagnosing, the pump stayed on and I couldn't stop it. Went to the car over an hour later and it was still running, had to pull the fuse to stop it.

Also, I have noticed, that if I push the "ON" button on the FOB, the green LED only lights up for 2 seconds, and no more flashing, but the manual says that the green LED should flash as long as the FBH is running. The FOB battery is new.

Also worth mentioning is that the FBH works perfectly fine as an additional heater to warm up the engine at cold ambient temperatures. It just doesn't work as a parking heater anymore. So can't be the faulty glow plug as I understand.

DOES ANYBODY HAVE A CIRCUIT DIAGRAM FOR THE PCB?
Any help is appreciated!

Cheers
Keijo

[Jules]

Frenchmike has sadly disappeared.
Steve & Rob from the Midlands do a good service by all accounts .........

webastorepairs.co.uk

[-Joe]

I think the webasto water pump may be the problem. With my FBH the impeller blade had fallen off and would jam or ratlle and not pump properly.

[bl52krz]

Go directly to the experts:- Devilish....... Trebor. You will get the correct answer.