Webasto! Why won’t it work on its own…. VCDS enabled??

Here's the official 'additional heater' manual for the A2 - scour it for clues and info.

This explains there is something within the E87 climate unit sends the 'fire up' signal to the ECU and then the Webasto when all the criteria are met.

Mine still won't fire up even after replacing the malfunctioning temp sensing component on the webasto circuit board. I think the thing in the E87 could be the culprit behind these issues but no idea on what a possible fix might be.

Hopefully the manual might give somebody the clue we are looking for.
 

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I've had a quick read of the above, and, forgive me if I sound as if I'm teaching granny etc, but I think you are being to narrow in your troubleshooting.
For example, one condition for the Webasto to run is engine revs above 600 rpm. This will only be true, if the ECU knows the Webasto wants to run, and adjusts the engine speed for that, as it does for aircon. If the car has climate, then the climate controller has to tell the engine, if no climate, there must be a similar Comms route. Check the engine measuring blocks to see if the appropriate bit is set, when the Webasto should run, and check that the rpm is above 600 rpm.
Battery voltage is another condition that must be met, for the Webasto to run. Again, if it's low, there will be no DTC.
Maybe this is why somebody mentioned it fired up 5 minutes into the journey. Maybe it took that time for battery voltage to reach the threshold?
The Webasto may well be DTC clear, but unless conditions like the engine speed are met, it won't run, but no DTCs will be generated.
Similarly, there must be measuring blocks in the Climate Controller that can be checked.
It's annoying that VCDS does not show a label file for HVAC, as that would help identify the measuring blocks, but the engine will definitely shows them.
Give me an engine code, and I'll look at the ECU label file. Hopefully, I can give you some Group/Blocks to look at.
Mac.
 
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Here's the Aux Heating measuring blocks for the AMF, probably the same for other engines. Voltage has to be 13.0 volts, so good battery and alternator required.

016,0,Auxiliary Heating (Group 016).
016,1,Generator Load,,Range: 0.0...100.0 %
016,2,Auxiliary Heating,Shut-Off Conditions,xxxxxxx1 = Coolant Temparature above 80.0 °C\nxxxxxx1x = Generator Malfunction\nxxxxx1xx = Battery Voltage too Low\nxxxx1xxx = Engine Speed too Low\nxxx1xxxx = Start Delay active\nxx1xxxxx = System Malfunction (G62 OR G72 FAULTY)\n1xxxxxxx = Ambient Temperature above 5.0 °C
; xxxxxxx1 = Coolant Temparature above 80.0 °C
; xxxxxx1x = Generator Malfunction
; xxxxx1xx = Battery Voltage too Low
; xxxx1xxx = Engine Speed too Low
; xxx1xxxx = Start Delay active
; xx1xxxxx = System Malfunction (G62 OR G72 FAULTY)
; 1xxxxxxx = Ambient Temperature above 5.0 °C
016,3,Heating Element,Activation,1x = Relay for High Heat Output (J360) ON\nx1 = Relay for Low Heat output (J359) ON
; 1x = Relay for High Heat Output (J360) ON
; x1 = Relay for Low Heat output (J359) ON
016,4,Supply Voltage,(Terminal 30),Range: 0.0...20.0 V\nSpecification: 13.0...15.0 V

Mac.
 
PlasticMac said:
Here's the Aux Heating measuring blocks for the AMF, probably the same for other engines. Voltage has to be 13.0 volts, so good battery and alternator required.

016,0,Auxiliary Heating (Group 016).
016,1,Generator Load,,Range: 0.0...100.0 %
016,2,Auxiliary Heating,Shut-Off Conditions,xxxxxxx1 = Coolant Temparature above 80.0 °C\nxxxxxx1x = Generator Malfunction\nxxxxx1xx = Battery Voltage too Low\nxxxx1xxx = Engine Speed too Low\nxxx1xxxx = Start Delay active\nxx1xxxxx = System Malfunction (G62 OR G72 FAULTY)\n1xxxxxxx = Ambient Temperature above 5.0 °C
; xxxxxxx1 = Coolant Temparature above 80.0 °C
; xxxxxx1x = Generator Malfunction
; xxxxx1xx = Battery Voltage too Low
; xxxx1xxx = Engine Speed too Low
; xxx1xxxx = Start Delay active
; xx1xxxxx = System Malfunction (G62 OR G72 FAULTY)
; 1xxxxxxx = Ambient Temperature above 5.0 °C
016,3,Heating Element,Activation,1x = Relay for High Heat Output (J360) ON\nx1 = Relay for Low Heat output (J359) ON
; 1x = Relay for High Heat Output (J360) ON
; x1 = Relay for Low Heat output (J359) ON
016,4,Supply Voltage,(Terminal 30),Range: 0.0...20.0 V\nSpecification: 13.0...15.0 V

Mac.
Click to expand...
THats cleared up a few myths :) well done, so, 5 deg c ambient, coolant below 80 deg c, 13v battery and it should fire up, unless there a start delay programmed in, wonder thats all about...
 
When I had AMF with webasto (not working) I was investigating it and as far I could understand ECU sends on/off signal to Webasto if conditions are met (conditions mentioned above). So if ECU logic happy it simply shorts start command wire (the one between panel and webasto) to ground , on some other Audi/VW webasto is on CAN network and those are started by "coded message" rather than gnd/12v state of control wire....

"PLUG 6 6-way connector -
PIN 3 - Cut-in signal for the "additional heater" (earth from engine control unit -J248) - The signal is received from the control unit for the diesel direct injection system -J248 as soon as the given cut-in conditions are met.
◆ If in "diesel" type additional heaters, contact 3 in connector B is connected to earth, the additional heater is switched on.
◆ If the additional heater does not switch on for vehicles with diesel engine, check the adaption in adaption channel "10"
"

audi a2 j162 webasto electrics1.png
 
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PlasticMac said:
I'm guessing the glow plug has glowed, but hasn't detected burner starting.
Mac.
Click to expand...
I’m 99% sure that the glow plug also acts as the flame detector, the controller uses resistance values to detect it, so it probably neEd’s a glow plug, or just cleaning. I had one with this and a clean up sorted it. Get a new burner gasket as the old one will come out in bits.
 
datsundrew said:
I’m 99% sure that the glow plug also acts as the flame detector, the controller uses resistance values to detect it, so it probably neEd’s a glow plug, or just cleaning. I had one with this and a clean up sorted it. Get a new burner gasket as the old one will come out in bits.
Click to expand...
This is correct, at the beginning glow plug acts as heat source to create flame with fuel and air, then it is off and used as sensor of high temp when flame is in combustion chamber,
 
I wish there was a way to purge out the old diesel fuel between the pump and the Webasto before it starts up as the stale fuel does not burn cleanly and probably gums up the glowplug. Although not diesel, stale glow fuel certainly gums up my r/c helicopter engines and is the reason I run them dry before packing them away.
 
Ok so the combined knowledge of this great community and some reasoning and experimenting appears to have arrived at a conclusion

There are a number of parameters which must be met for the webesto to kick in
Engine coolant temp below 6 deg C as seen by the webasto (not the engine ecu) and not greater than 80C (again as seen by the webasto)
Engine revs above 600rpm (never an issue on the tdi as the ecu keeps it at 925 give or take)
Control panel not set to econ

There is however another (as far as I’m aware not documented) criteria. The engine ECU must be on coding 00002
I’ve no idea why this is the case but changing nothing else except the coding from 00002 to 00005 stops the webasto firing up
Change the coding back to 00002 and the webasto fires up

All 1.4TDI’s A2’s came out of the factory with the engine ecu coding set to 00002
As such the webasto is able to operate when the above criteria are met.
The problem comes, if for any reason eg a remap, the coding is changed to 00005
This was unknown to myself until earlier today

I can’t prove this on my own car as some investigation with vcds yesterday evening revelled the webasto is faulty in that the temperature reading is constantly on 112 deg C which it definitely wasn’t last night and this must be lower than 6 and less than 80

Thanks to all who have contributed to the above thread

Paul


Sent from my iPhone using Tapatalk
 
audifan said:
I wish there was a way to purge out the old diesel fuel between the pump and the Webasto before it starts up as the stale fuel does not burn cleanly and probably gums up the glowplug. Although not diesel, stale glow fuel certainly gums up my r/c helicopter engines and is the reason I run them dry before packing them away.
Click to expand...
If you disconnect line and use suction pump similar to bleeding brakes one it should remove most of it, pump just pushes fuel up with pulses to be dropped on kind of mesh to be burned in chamber
 
Yes I know how to do it manually, but would have been nice for the system to do this either before each attempted start or at least after a period of inactivity i.e warmer weather to colder.
 
depronman said:
Ok so the combined knowledge of this great community and some reasoning and experimenting appears to have arrived at a conclusion

There are a number of parameters which must be met for the webesto to kick in
Engine coolant temp below 6 deg C as seen by the webasto (not the engine ecu) and not greater than 80C (again as seen by the webasto)
Engine revs above 600rpm (never an issue on the tdi as the ecu keeps it at 925 give or take)
Control panel not set to econ

There is however another (as far as I’m aware not documented) criteria. The engine ECU must be on coding 00002
I’ve no idea why this is the case but changing nothing else except the coding from 00002 to 00005 stops the webasto firing up
Change the coding back to 00002 and the webasto fires up

All 1.4TDI’s A2’s came out of the factory with the engine ecu coding set to 00002
As such the webasto is able to operate when the above criteria are met.
The problem comes, if for any reason eg a remap, the coding is changed to 00005
This was unknown to myself until earlier today

I can’t prove this on my own car as some investigation with vcds yesterday evening revelled the webasto is faulty in that the temperature reading is constantly on 112 deg C which it definitely wasn’t last night and this must be lower than 6 and less than 80

Thanks to all who have contributed to the above thread

Paul


Sent from my iPhone using Tapatalk
Click to expand...
Think coding you mentioned could be in regards to type of webasto where one fitted in a2 can only run when engine is running and criteria met while other types can be started when car parked on timer say half hour before trip as it is fitted with its own coolant circulation pump
 
robskiA2tdi said:
Think coding you mentioned could be in regards to type of webasto where one fitted in a2 can only run when engine is running and criteria met while other types can be started when car parked on timer say half hour before trip as it is fitted with its own coolant circulation pump
Click to expand...

You mis understand. The coding is on the engine ecu NOT the webasto
The engine ecu must be coded to 00002
The webasto is also coded to 00002 (I read about different instals of webasto’s and the coding of the webasto to suit but this is not the issue we are having)

Paul


Sent from my iPhone using Tapatalk
 
I’m going to let Paul explain how and why my webasto is now working, as he has way more knowledge than I will ever have. Long story, but you may remember the big problems I had with Lights on the dash on our silver tdi, where I replaced absolutely everything trying to sort the problem…..sensors, bearings, abs looms, Yaw sensor, brake switch, bulbs, and abs unit rebuilt etc.
after many hours and parts it turned out to be the alternator!
In desperation there was a suggestion that it could poss be an ECU fault, I was working 100 miles away and my husband needed his car….stressful times!
I bought a replacement ECU with the immobiliser disabled, (as there was also an occasional fail start due to immobiliser blocking ) and had it mapped at the same time in case it was that to save postage etc.
This obviously made no difference, so i now had a spare mapped ECU for any AMF engine, then fast forward a few months Chad, the tdi turned up on here for spares and I bought it. (Look up journey of Chad for a reminder)
I decided I preferred Chad to my tidy but poverty spec silver tdi, and Sold it to my brother. Chad was given a new personality with the spare ECU and all was well.
This car has been brilliant, but the webasto never worked, and this is why I started this thread as it drives me mad that it will only fire on VCDS!
The previous owner told me that everything worked as I passed over the £380.. air con, OSS roof (ish), webasto.
After posting this thread it occurred to me that it might be worth plugging in the original ECU, so a rummage in the garage, plug it in…AND THE WEBASTO WORKS!!!!!😀😀😀😀😀😀😀😀
I swap them back, no webasto!
A long conversation with Paul last night and I carried out a test this evening and changed the code from 00005 to 00002 on ‘1’ an the webasto now fires, so it definitely down to the coding of the ECU that gives the instructions to the webasto
😀😀
 

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depronman said:
Ok so the combined knowledge of this great community and some reasoning and experimenting appears to have arrived at a conclusion

There are a number of parameters which must be met for the webesto to kick in
Engine coolant temp below 6 deg C as seen by the webasto (not the engine ecu) and not greater than 80C (again as seen by the webasto)
Engine revs above 600rpm (never an issue on the tdi as the ecu keeps it at 925 give or take)
Control panel not set to econ

There is however another (as far as I’m aware not documented) criteria. The engine ECU must be on coding 00002
I’ve no idea why this is the case but changing nothing else except the coding from 00002 to 00005 stops the webasto firing up
Change the coding back to 00002 and the webasto fires up

All 1.4TDI’s A2’s came out of the factory with the engine ecu coding set to 00002
As such the webasto is able to operate when the above criteria are met.
The problem comes, if for any reason eg a remap, the coding is changed to 00005
This was unknown to myself until earlier today

I can’t prove this on my own car as some investigation with vcds yesterday evening revelled the webasto is faulty in that the temperature reading is constantly on 112 deg C which it definitely wasn’t last night and this must be lower than 6 and less than 80

Thanks to all who have contributed to the above thread

Paul


Sent from my iPhone using Tapatalk
Click to expand...
Good team work! I absolutely love this community on here, so much information and so much help shared with everyone.
 
datsundrew said:
Good team work! I absolutely love this community on here, so much information and so much help shared with everyone.
Click to expand...

Absolutely agree
Could I suggest that you post another picture in the above post with the correct 00002 engine ecu coding. Someone may well pick up this thread in years to come and it would be slightly confusion that the words and pictures do not align

Cheers. Paul


Sent from my iPhone using Tapatalk
 
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