As per the first posts of this thread, when the FBH starts the fan will run and the unit self-checks the operation of the various system components. If any aren’t present it will shut down. This is usually after 2.5 mins of start up and a system fault will be logged. From what I recall, 3 failed attempts at starting the FBH will lock itself out until it is reset by removing and refitting the fuse. Typical causes for failed start are: Battery voltage lower than 10 volts; glow plug open or short circuit; circulation pump open or short circuit, PCB board fault and finally fuel dosing pump failed thus no fuel to the heater. I can’t speak for FFRR’s but in my experience with FBH’s in other cars the dosing pump is often the culprit. It is solenoid operated, so you should be able to hear it and feel it clicking. As these can stick after long periods of inactivity. A gentle tap with a hammer will sometimes work. Worth looking at

I just find the FBH so "variable". Since my previous post I have changed FFRR to a 2011 model but the FBH was still not working on the remote, yet it always ran as an auxiliary heater on startup, i.e. in the mode to help speed up the warming up cycle on the engine.

Have swapped out to a new AGM battery which didn't really make a lot of difference and then reset the remote which did improve things.

Worked a few times after that and actually produced hot air

Now I find it starts on the remote and will run for maybe 5 minutes, diesel pump working, burner working etc then shuts down.

Bizarrely if I then go out and open a door, it fires up again for another few minutes

There almost seems to be something about when the BCM shuts down/starts up based on the normal timed cycle for this that then is triggering the FBH activity......

It could definitely be a voltage sensing issue, but not a battery drain as the battery(ies) have been new and fully charged....

On the battery thread I have previously pondered if the various settings in the CCF for batteries, H8, T8 etc have anything to do with the way the ECU is calculated battery drain/capacity, but no one seems to know what these codes mean so it is difficult to program a new battery to the car using them

Cheers,

MM 2011 TDV8 AB
2006 TD6 AB (Gone to Wales)

jonnyboy54321

Hi Jonnyboy, do you have any contact details for frenchmike, I think I need the ECU checking on my FBH before digging deeper . Is the ECU within the FBH ie do you have to take the FBH off to access it or is it separate.

Thanks

Maccaa Current FF Westminster 4.4 V8

search for French mike on here and you will see los of posts andnthings folks have done to fix FBD+H.

Try this email address,

tignous84@free.fr

http://www.the75andztclub.co.uk/forum/showthread.php?t=71982

Thanks for the contact details Dolphinboy, I think my head is numb with all the data I've taken on board over FBH's but the glow plug is showing as faulty on the Webasto software, but the FBH works when the car is running, so I'm erring on a check of the ECU as this seems an inherent ECU issue throughout a number of thread s that I've digested.

Cheers

Maccaa Current FF Westminster 4.4 V8

So how do you know if you have FBH was it a standard fitment? an extra or comes with certain models? 2012 Vogue 4.4 TDV8 - Current
2014 Navara V6 - Gone
2004 Vogue TD6 - Gone
Grand Cherokee - Gone
Discovery V8 (LPG) - Gone
Discovery TD5 - Gone

Al diesels have an FBH (to heat the engine up quicker as these run very cool and will affect heating and efficiency otherwise.) Some petrols have them as an option (my 2004 Autobiography does).

however to have the ability turn on remotely, there needs to be a remote receiver unit in the back (right?). Also you can check your build data (topic or VIN query)to see if it is fitted.

I also has a lot of problems last winter with FBH. Sometime it works, sometime not. But even when it works, there was other things I dont like.
1. Working time only 20min. Interior not going warm in this short time.
2. Engine stay cold.
3. Battery going empty during Webasto running (if use it twice), couple mornings car not start.

So I install compleatly different system to my car.
First I buy brand new Webasto with analog controller to 100% avoid any issues in future. Analog - to avoid any issues from Climate Control side. Also I buy and install battery charger and electric heater from Defa 2200W.
Our Telestart reciever give analog +12V signal to start the Webasto (to pin 1) when press remote control "on" button. This signal stay on for 30 minutes. Original Webasto ask the permit from Climate Control via K-bus (pin 2). Analog Webasto not need any permit and not communicate with CC and starts immidietly when got +12V to pin 1, and continue working during +12V presist on pin 1. Of course in this case interior blower not run and FBH heat up only the engine. For me thats ok, I install electric heater in the cabin. This heater get 230V from grid through the relay, wich get "on" signal from same Telestart. So now when I press the remote control button, interior heater start and Webasto go on and pre-heat the engine. And at the same time charger charge the battery during night. Also I install separate button to operate Webasto during driving. Usualy I leave FBH on during driving in cold conditions.
Of course this solution is not suitable for everyone, need 230 grid near car. I have it. But now I can be 100% sure car will start in all winter conditions, engine is warm and interior is also very warm, 2200W is more than enough. And the battery is also full always, even when driving short distance and use Webasto.

Some pictures of the valve mod would be nice SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

I done this last winter. It was cold and unfortunately didnt take any pictures.
But here some drawings how I do it.

Love your work Mate! SOLD | Tuned MY 2011.5 Range Rover Autobiography 4.4 TDV8 Orkney Grey | e-diff | ACC

New Toy: Unimog U1550L/37
New : G350D

Does anyone have a link to the thread about mentioned PCB problems with resistors?

My 2011 4.4TDV8 FBH has had a circulation pump related problem since last winter.
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.
It always throws a fault B12A6-15 under the HVAC module - Auxiliary heater water pump - General electrical failure - circuit short to battery or open.
So last winter I tested the pump - It had the correct resistance and also ran well when applied 12V.
I even tried another good pump on it and still the same.
Now as I've put in a new Bosch AGM battery and the issue still persists, I am pretty certain that the problem lies in PCB.

Cheers
Keijo

There's a link in the thread posted above to it, here's the one I found useful. https://www.the75andztclub.co.uk/forum/showthread.php?t=53896