Yes the pumps starts after about 25 to 30 seconds and clicks/pluses every 1.5 seconds

Once the FBH has detected a flame the clicks/pulses increase to every 0.75 of a second

Flame detection is done with the resistance of the glow plug changing, very simple units really

Mine was really covered in carbon deposits so I assumed that it was the glow plug and changed it
£160 for glow plug and flame tube but turned out not to be the glow plug

Resistance of the glow plug to earth should be @25 degrees c should be 0.324 to 0.360 ohms

I have full work shop manual if you need it, and can send link just let me know. RANGE ROVER 04 TD6
RANGE ROVER ULTIMATE EDITION 2012
UPGRADE.
MK 4 SATNAV
http://www.flickr.com/photos/jrautoelectrics/

Hi again

Just to confirm (i had posted the fault code wording from memory as i thought one code = one fault)

Just been out to check and the exact code is;

002 glow plug flame detector short circuit to ground



Been looking around breakers and ebay for 2nd hand units in case i can pick one up cheap, and it looks like there are loads of units for sale on german ebay from BMWs. Are they likely to have the same controller / ECU?? 

Yes they are

I bought a second hand one from a breakers local to

It came off a 2002 BMW 5 series

I split the second hand one down and fitted the
Ecu/heat exchanger to my original parts
Fan,burner unit, water pump . RANGE ROVER 04 TD6
RANGE ROVER ULTIMATE EDITION 2012
UPGRADE.
MK 4 SATNAV
http://www.flickr.com/photos/jrautoelectrics/

I tried to put mine on this morning, remote had new batteries, fans came on, looked like it tried to fire up, the fans kept running but no warm air, fuel pump was ticking, on the first try a little white smoke from under the car, left it running for 10 mins, no warm air. should the air coming out of the vents feel warm? I will try it again to see if it just needs a bit of coaxing into life.

Me thinks a trip to the stealer for another warranty claim may be on the cards though. Gotta love it.

Jutlst tried again, could feel the flue venting under the car, it was cold and only ran for a few minutes then stopped.
Methinks is broken...... There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
Fiat 500x 1.4 multiair Lounge 2015
2010 LR D4 Commercial 2.7 TDV6

Well after all the planning and research i was going to start my diagnostics this weekend.......


BUT - I manged to source a second hand part from Jon Daunter (www.rubbishlandroverbreaker.com) for £150 plus £10 postage!!!

[EDIT] - HAVE NOTHING TO DO WITH THESE GUYS - HAVE BEEN ON THE PHONE ABOUT 15 TIMES TRYING TO GET THEM TO COLLECT AND REFUND THIS FAULTY PART, AND HAVE JUST HAD TO REFER IT TO MY CREDIT CARD COMPANY - RUBBISH!!!

So it should arrive tomorrow, and i'm just going to get local mechanic to fit it as it should (hopefully) be a straight swap.

Good to know though, that the unit from a 5 series BMW is the same and has the same ECU - as these are widely available on ebay.de

Also may be useful to know that the ECU repair guy on ebay is sure he CAN recondition these ECU for £90 so this may help someone else.

I'll hopefully be able to post back by the end of the week to say all fixed (fingers crossed).

Useful links;

ECU repair service (£90)

Quote - "We have repaired many controller variants and we can diagnose and test your controller aswell.

You can contact me directly to my email if you find that the fault is in the controller."

webasto thermotop reconditioning service (£295) but cannot fix the ECU

Jon Daunter Breakers - RUBBISH

[EDIT] - HAVE NOTHING TO DO WITH THESE GUYS - HAVE BEEN ON THE PHONE ABOUT 15 TIMES OVER THE PAST 6 WEEKS TRYING TO GET THEM TO COLLECT AND REFUND THIS FAULTY PART, AND HAVE JUST HAD TO REFER IT TO MY CREDIT CARD COMPANY - RUBBISH!!!


Webasto thermotop manual

Hope that helps someone else, and thanks for all the helpful advice as usual.  

Last edited by Aurrian on 29th Nov 2012 10:37am. Edited 4 times in total

An update - still not fixed yet

Mechanic replaced my FBH with the second hand unit - he commented that mine looked almost new and the one he put in was very rusty

So it doesn't work..... Now no communication with the FBH ECU at all!! I think it's a dud unit and will have to send it back.

However i have now had the opportunity to dismantle and investigate the original unit.

Generally pretty clean - there was a bit of carbon build up in the burn chamber - but not a lot. I cleaned that out.

Air pump working with 12V feed

Glow plus sensor glows with 12V feed

Glow plug resistance 1.3 ohm

Water pump - seems to be dead - reversed polarity - still nothing.

Water pump resistance = open circuit no continuity! That's not right is it?? a motor should have continuity??

The motor itself looks to be sealed in a black casing - no obvious way to open it up. (says pierburg on it)

If that's the problem - why would the error code be "002 glow plug sensor short to ground"?

Is it likely that the ECU is kaput too - and it left the motor on and burnt it out?

I was just about to send the ECU to finland for diagnosis but not sure whether to get a new motor first and try that.

Other option is to get the motor from the replacement FBH back out of the car and try that - but means getting it in and out of the car again.


Any ideas / suggestions welcome !!! 

webasto Thermo Top Troubleshooting Tree pdf
http://www.raini.ch/files/webasto_Thermo%2...20Tree.pdf 
RRC 2Dr, RRC 4Dr,
P38, and 2 L322s
(wife thinks I'm nuts - prob right, too)

Thanks Steve

Not sure i understand all of that but i have taken 2 assumptions, please confirm if this is correct;

1 - if i apply 12v to the coolant / water pump and it does not run - it's broken ?

2 - I'm going to re-assess the fuel pump and apply 12v, but it might just need a wee shake to loosen it off.

thanks again 

Hi Aurrian

Just looked in my garage for you but think I sold my old water pump
Just the blower fan left over.


Yes sounds like you water pump is knackerd, Apply 12V directly to the pump (+ to black and – to brown)
Could also try putting a hose pipe on it with full pressure As these are also known to seize up with lack of use

Try the faulty FBH you bought and see if that water pump works if you got one with it

Let us know how you go RANGE ROVER 04 TD6
RANGE ROVER ULTIMATE EDITION 2012
UPGRADE.
MK 4 SATNAV
http://www.flickr.com/photos/jrautoelectrics/

Thanks guys.

The hose is a great idea! !

I'm on holiday this week, I will try when I get back.

Meantime, the ECU is on its way to Finland to get checked anyway, and I've ordered a new coolant pump.

The cost on this one is mounting up. Only consolation is that the alternative is to but a new unit and that would cost well over a grand.

I'll keep you posted. I'm sure there will be a happy ending.. .. 

Hi guys,

Mine is still playing up. The burner lights ok, but no warming.

On reading the above posts i think the water pump could be at fault.

Is it possible to connect a hose to the fbh without removing it from the car? There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
Fiat 500x 1.4 multiair Lounge 2015
2010 LR D4 Commercial 2.7 TDV6

Hi guys, I found this tread whilst looking for something else so thought I'd stick my oar in. I am a factory trained Webasto, Mikuni & Wallas heating tech and Advanced marine Electronics Tech, though my business is marine based, the TTV is operationally similar to a TTC with ECU mods and sometimes (when used as an auxiliary rather than a pre heater, without a water pump. The advice given so far has been accurate but one thing, the fault codes though a guide should not be relied on as absolute and can be misleading, I use a Thermotest diagnostic laptop which is specific to the heaters and the sensor readings often do not relate to the actual code. The main reason for faults on these things is poor installs (not applicable to factory option units) I have nothing to add to the specific diagnosis as it has been almost certainly narrowed to the circulation pump, these units check all parameters before starting so would not even try with a faulty pump. The best advice I can give to people who have these fitted is to run them at least once a month even in summer, this helps prevent seized bearings, pump vanes etc and ensures that the dosing pump and lines have fairly fresh diesel in them too, they are only 2mm ID and can easily block and the pump can stick indicating an expensive fault when all it needs is a "Whack". Last point, earlier in the thread somebody mentioned applying 12vDC direct to the glow pin, be very careful when doing this and never more than briefly, The ECU actually pulses the power and direct application can damage the glow pin if allowed to remain more than a few seconds.

Final Final point, this is not a tout for business, I am not interested in getting dirty on road vehicles and anyway marine is far more more lucrativ e.

thanks webo!

That's really useful info as i was very confused in that the error code did not seem to make sense with a faulty circulating pump.

Also really useful to know that the glow plug can be damaged (fortunately i only allowed it to glow briefly).

Maybe i did not need to send my ECU off then - but prob still worth getting it checked anyway.

@northernmonkeyjones - I'm not sure if it is possible to connect a hose to the FBH without taking it out of the car, but i don't think it would be possible - it was tricky enough dismantling it on the bench. If no-one else can tell you - i'll let you know once i've tried the re-install. 

I have just had a bit of a fiddle this morning, arch liner out, tried to run it.

The heater fired up ok, hot exhaust, fuel pump running, but after a min it sounded like the pump was struggling, bit of a soft crunching noise, feeling the outlet pipe it was pulsing/bulging ever so slightly felt like there was a restriction upstream somewhere. So i clamped off the hoses and removed the inlet pipe, let a bit of coolant run back through the pump, then re assembled. Crunching now gone. Ran it again, outlet hose heating up, inlet hose heating up after.

Still only slight heat in the cabin though and it shut itself down as the battery was getting a bit low (new battery required it think). Looking at it on the car it probably would have just been possible to attach a hose to run through the whole unit whilst attached to the car with both inlet/outlet hoses removed, a bit fiddly but possible.

Going to leave it alone for a week or two and then try it again, as it seems to be running fine as part of the engine heating sequence.  There is nothing that can't be fixed with a hammer😜😜
FFRR 4.4 SDV8 Autobiography Santorini Black.
Fiat 500x 1.4 multiair Lounge 2015
2010 LR D4 Commercial 2.7 TDV6

Final (hopefully) update.

Got the ECU back from "sercap" - It took just over a week turnaround, and it was £10 to post royal mail to Finland so £100 in total. It came back with 2 test reports - arrival (showing glow plug fault) and final report (showing no errors). Several components from the ECU had been replaced and re-soldered.

And...it works!

My original water pump was fine - i took the top cover off. put it back on, retested it and it worked - so that was not the problem.

Removing and replacing the FBH took less than 3 hours, and getting the wheel arch liner off and on was the most tricky part. The fuel line clip is almost impossible to replace and you want a v small jubilee or fuel line clip (approx 10mm).

So i just need to send the faulty FBH back to Jon Danter, and sell the surplus coolant pump on ebay (unless anyone wants to buy it!)

Thanks for all the help guys. I would never have attempted fixing something like this before i was a member of this forum and have saved myself a packet



Thanks for all the help from everyone