Disco 2 Webasto Fuel Burning Heater install

This site contains affiliate links for which LandyZone may be compensated if you make a purchase.
Are you priming the pump or testing it from the diagnostic screen?
I could test the pump circuit on the bench by using a bulb instead of the pump you can see it flash.
 
This is all on the work bench at the moment. The fuel pump is connected directly to the test battery earth as is the fbh.
I can activate the fuel pump using the software so I know that's all good.
I no longer own a scope so cant trace canbus on pin2.
I can pull the unit off the D3 and connect it up to this unit and push a w-bus signal on pin 2 if I need to just to see what happens.
 
If everything passes the test and you get the red FD led on doing glowpin test I reckon you have a good unit but it needs to talk to the car.
I haven't scoped it on the car but on the bench the FBH sends out 12v which drops at regular intervals creating a -ve pulse with respect to the 12v, I was told that the car grounds this signal (presumably in a specific pattern creating a +ve pulse ) as a response. IMO that the D3 FBH will also send 12v with a -ve pulse so would not respond to the L322 FBH with the right message. I think you need to find a way of connecting pin 2 to the car.
 
Yes black I'm sure your correct. My car should have the plug fitted somewhere to talk to the fbh BUT iv got an analogue board comming this week to completely by pass the issue. :D
I'm still going to find away around the issue with the original board for future reference. My research suggests shorting pin 3 to earth will fire it up. Iv nothing to lose doing it iv found the webasto installation pdf and it clearly shows this if installing the unit to work off a switch.
There are x2 main fbh units with part numbers on 1st one says pin1 +12 volts to activate the other part number says ground pin 3. Of course the part number on mine is different :rolleyes:
 
Both parking and engine warmer to help the lpg along this time of year.
Iv recently had a fsr fault which actually turned out to be the +12volts connection in the plug to the fsr. Iv got a new fsr and plug sitting here. The reason the +12v pin has burned out is because the fsr has been replaced before and not fully pushed home meaning it wasnt in the cool air stream properly and over heated the plug.
When I can get under the dash to cut the old plug out and solder in the new I'm going to have a play around and see if I can get it to fire up the fan motor directly by putting 12volts on it.
Fingers crossed .
Mite even try adding a switched 12volts to the relay pin in the fuse box
 
Don't know if you've checked the diagram or not. The only one I have for the older model is for the 2003 LHD V8 but probably still valid and it does show a connection to the HEVAC
Looking at the diagram it shows a K-BUS signal which I have still to learn about but would imagine it's not just a 12v feed.
It sounds like you're getting closer to a solution though :D


upload_2021-2-3_0-39-23.png
 
Pulse generator.

Going to try one of these they put out a square sine way going to see if I can fool the fbh with this, it pretty much matches the can bus.....I hope
 
Last edited:
found a 2001 diagram from fulfatrr but almost the same.
I suppose the signal generator is worth a try for a few quid but given the Webasto software must send different commands to test each component IMO it's can't be a fixed wave pattern, it must change depending on what the software is asking it to do.


upload_2021-2-3_0-56-45.png
 
Hi , Just been reading this thread and found it very interesting. I've retro fitted a Webasto TTC to my D2 , I have it coming on 3 different ways , 1 by just starting the engine , 2 via a cheap remote really, or via a switch that I've mounted under the cruise control switch on the dash clock surround. It works well gets up to 72 degrees quite quickly then in goes in to half power mode . I've had a few issues recently with it , the combustion fan failed to got a reconditioned one off Ebay, then it was smoking too much which turned out to be the foam filter in the intake pipe being too restrictive (mine is out of a Rover 75) then it was taking an hour to get to 41 degrees so I chucked the cheap Chinese fuel pump in the bin and fitted a Genuine Webasto pump. The next job I want to do now it wire it into the Climate Control unit. I must add when I first got the unit from a Rover that was in a breakers yard the heater wouldn't work , so I sent the PCB off to be repaired by French Mike I found him via the Rover 75 forum.
image(1).png
20220118_184441.jpg
20220109_150612.jpg
20190123_171017.jpg.8375b70d97537791c4e6e82d6e801c2b.jpg
image(1).png 20220118_184441.jpg 20220109_150612.jpg 20190123_171017.jpg.8375b70d97537791c4e6e82d6e801c2b.jpg image(1).png 20220118_184441.jpg
 
Hello folks. I'm new here.
Can you please tell me if i can fit a Rover75 TTC on my Discovery2?
FBH it's using the same firmware on both cars?
 
You must log in or register to reply here.

Similar threads

G
TD5 Noisy fuel pump
Replies
3
Views
421
Anaconda
A
C
Fuel gauge reading
Replies
5
Views
621
tilly2
T
W
losing fuel prime
Replies
10
Views
518
woo0003
W
E
Disco 2 Fuel Leak
Replies
1
Views
278
Landmark2
Landmark2
J
Discovery 2 td5 failed r9 to fuel pump
Replies
11
Views
2K
Jambo2301
J
Back
Top