XSeries-forum

Got a 3.0D facelift April 2006. I bought from the as new purchaser who said the Webasto never worked but that he never got round to taking BMW to task over it (He was a busy BA pilot!). Cut to the  chase, if I pulse 12v on the pump, I get a healthy fuel supply to the unit, power to the fan = good air flow through the unit, power to the water pump = healthy water return visible through the coolant reservoir - BUT the fan starts on any 'wake-up' and nothing else happens. PCB issue? (Oh and nowt on hot wiring to pin 1 either!) ?

PS - just got the Webasto apart - all as clean as a whistle - no deposits, no thermal discolouration, all shiny alloy - looks like it has never run!

PM Jaynana, he knows the Webasto like his 3rd child!

3rd child has been slightly out of sight and out of mind.. due to the summer.. tried it today it worked!

we have collectively written a thesis on this subject, over here

mine looked worse than a chimney with the glow-plug fused with crud inside the burner! in fact i believe my glow plug got short circuited due to that..

in general i'd start here, but i think you've gone past this stage:
- fault memory has not fault recorded against aux heater
- battery voltage over 11.8v (pcb has a cutoff point leaving enough batt to start the car)
- sufficient fuel (don't try if fuel light is on as the webo fuel pick-up is slightly hgh in the tank)
- hot wire to pin 1(? can't remember the pin) - starts air fan within 30 sec

things get complicated at this point, your in fault diagnosis. you either need something like the reslers interface to issue individual commands to the pcb to check each component (you already know each one works by checking them by hot wiring, but pcb needs to be able to call them up for service), or you will need to try swapping suspect components. in your case pcb and/or glow plug.

all in the thesis..

Thanks very much for that - I will follow up your advice. BTW do you know where I might buy a glow plug and service gasket set - used to be an e-bay seller who did but he's disappeared, Webasto only want to sell me a complete burner assembly @ £££!

try this guy.

he's in germany and guess what language he speaks! best of luck with google translator  )

Can I access the Webasto via the OBD and INPA or do I have to connect diagnostics direct to the heater - if the latter, how do I do this?

[quote="nujon"]
Thanks very much for that - I will follow up your advice. BTW do you know where I might buy a glow plug and service gasket set - used to be an e-bay seller who did but he's disappeared, Webasto only want to sell be a complete burner assembly @ £££!
[/quote]

Ill have a look in my loft when i get home as i have webasto bits all over the place........don't have one now on the e70.

Originally on mine it would go through a purge run but nothing else.  It does seem to be the PCB goes on them.

Another good place to look for parts is in the boating community as they use the webasto for hot water and central heating on boats.

[quote="nujon"]
Can I access the Webasto via the OBD and INPA or do I have to connect diagnostics direct to the heater - if the latter, how do I do this?
[/quote]

i used a webo diagnostic software with a k-bus interface. details in that 'thesis' i sent a link before.. INPA also can i think, never done it.

[quote="squeaky2"]
Another good place to look for parts is in the boating community as they use the webasto for hot water and central heating on boats.
[/quote]

correct on the glow plug, other accessories. actually maybe u should try that for the glowplug if you suspect it.

beware of buying the pcb off any 'boat ppl' though. that's because the webo C/Z variant is meant for cars not boats and the difference is it talks the car's communication language (plus the water pump is external). In bmw's instance it talks k-bus protocol. boat variant's pcbs wouldn't do that.

other idea is breakers..

[quote="jaynana"]
[quote="squeaky2"]
Another good place to look for parts is in the boating community as they use the webasto for hot water and central heating on boats.
[/quote]

correct on the glow plug, other accessories. actually maybe u should try that for the glowplug if you suspect it.

beware of buying the pcb off any 'boat ppl' though. that's because the webo C/Z variant is meant for cars not boats and the difference is it talks the car's communication language (plus the water pump is external). In bmw's instance it talks k-bus protocol. boat variant's pcbs wouldn't do that.

other idea is breakers..
[/quote]

Thanks for that - what interface and plug connection did you use to access the Webasto PCB? - I note the diagnostic software can be readily downloaded

i used the Reslers USB Version.. hmm.. URL to the software i downloaded doesn't work! maybe its changed or i got it wrong. anyways found it here.. (there are multiple versions listed there, i can't remember which was latest at that time but i used the latest).


Reslers device connects to pin 2 on the webasto, which is the k-bus on the BMW E53.

tbh, having gone down this safe and sure but painful path i'm not sure if i would advise another. it would indicate which components are suspect, but you can't tell for sure whether its actually that or the pcb!

mine indicated a faulty glow plug and a faulty fuel supply. i had no way of then knowing whether it was one or both of those or in fact none of those but the pcb or any combination of those! 

my point is even with that diagnosis and additional knowledge it still comes down to trial and error of suspect components.

in your case given all the component tests you've done like i said before, i would place my bets on either the pcb or the glow plug. i'd start with the cheaper and easier - the glow plug.

Know what you mean - if the controller cards on a digital system are OK in themselves, diagnostics will reliably tell you which input or output devices (sensors, bulbs, valves etc) are on the bum (as we say up north) - but if the controller cards are on the bum, they (via the diagnostics software) will tell you lies "Quis custodiet ipsos custodies" !

Mebbes in the future when its cheap enough, we will see majority software logic on cars as well as aircraft / express trains / liners etc

.......and no doubt the infamous BSOD too...... )

[quote="X5Sport"]
.......and no doubt the infamous BSOD too...... )
[/quote]

Hell! - you had one on a BMW?