Webasto Coolant Heater - Resetting Lockout

[Mark Rowland]

Just recently had trouble with the Eberspacher auxillary heater. It was trying to start but only delivered cold air. Long story short, it turned out that a mouse (or similar) had got on top of the fuel tank and chewed through the heater fuel line. So both heater pumps have only been drawing air and not diesel. Managed to fix the fuel line and the Eberspacher is now working fine. We couldn't test the Webasto as the air temp was above 5 deg C. Tested it this morning (+2 deg C & full fuel tank) and the Webasto coolant heater is not even trying to start and appears to be locked out. As it shares a common fuel line with the Eberspacher it has had more than 3 unsuccessful start attemps and I believe from reading other posts in this forum, that this can lock the Webasto out. Does anyone know how to reset this i.e. could I use a Carist OBD device to change the “flag” in the ECU, or will have to endure a trip to the VW dealer to get them to reset it?

Also big shoutout to the guys at P F Jones Stoke-on-Trent:

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For sorting out my original problem. Very knowledgable staff, superb service and excellent workshop. A great alternative to VW dealer for camper van issues.

 

[mrcheesbrough]

First thing - are you sure the coolant heater worked prior to the mouse incident?

I’m don’t think these heaters have a permanent lockout but perform a system check each time they attempt to start. If a fault occurs they will lock out until the next time the vehicle is restarted.

For testing purposes you can force it to start by bypassing the external temperature sensor. This is usually behind the front bumper. Not sure exactly where though as I don’t know what model you drive.

It maybe there is an airlock in the fuel line to the heater. Bypassing the temp sensor to force a start regardless may eventually clear this. Or you may even be able to check the pump is dosing by disconnecting the feed at the pump and forcing a startup.

Having written this it all sounds quite a faff and a quick (if costly) visit to your dealer to read the fault memory might reveal the repeated fault causing it not to start. Maybe worth a quick chat with them first to find out if they are even able to read the heater for faults as they usually have an onboard ECU.


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[Mark Rowland]

Thanks for you comments mrcheesbrough. I have a 2016 T6 Ocean with the factory Eberspacher cabin heater and Webasto coolant heater.

The Webasto heater was definately running the day before I resolved the fuel line issue. But when I say working, it was attempting to pump fuel and was running the turbine but not heating, the exhaust was only blowing out cold air. So this might have been its 3rd and final attempt to run.

I managed to get a Carista ODB reader and now get the following codes for the Auxilliary heater.

Auxiliary heater
Part #: 7E0963273A
Component: STH-T5GP2
Coding: 4101 (hex)
Fault codes:
00056 Blower engine for temperature sensors inside (V210)
00002 Transmission Control Unit
00057 Actuator shut-off valve b-column and floor space, right (V211)
00135 Left Front Wheel Acceleration Sensor (G337)

I think that the fault code descriptions may be wrong, especially the 00002 & 00135 as the Aux heater module can’t have anything to do with the transmission and the left front wheel acceleration sensor. But these codes could be something to do with my Webasto heater lockout issue. The Carista won’t clear these codes, so a dealer visit is looking more likely, unless I can find someone local with a VAG-COM which should be able to clear them.

 

[tdjrt]

Hi, I've just had this problem on my T6. It wasn't as straight forward as I hoped but managed to unlock it via VCDS. Where in the world are you? Near South Wales? I could help.

 

[flying banana]

heres a thought.try and start the heater. but not the engine. then remove its supply within 12 seconds. ie disconnect the battery. then retry it. sounds daft but this is how we reset locked out coolant heaters on trains ?

 

[Mark Rowland]

I managed to get the Webasto issue sorted a few weeks ago. After a lot of failed attempts with the VCDS and pulling fuses I decided to take my van to the main dealer as it had the Adblu recall outstanding. I asked them to reset it whilst they were updating the software. All sorted now.