# Aux heater locked / Not working



## Elliot-Lowndes (Sep 6, 2015)

Hi everyone.

I've had VCDS for a while now but only just started using it for anything other than checking DTC's.

Ever since I've owned it I've had a fault on there of Aux heater locked - I always just naively assumed this was a spurious fault since everything worked as it should and I was under the impression I didn't have an Aux heater (I only found out recently that all diesels do have the heater installed).

I came to the car today to enable the auxiliary heater as per entwisi's instructions. After clicking security code I entered 22106 which was accepted, changed channel 09 from 1 to 2 and changed channel 04 from 1 to 0. All good, I now have the aux heater screen available to me and can set the timer. However I cannot select 'heating' with the softkey and the heater does not come on with the timer (This was when the penny dropped about the Aux Heater locked DTC. :facepalm: Better late than never!) Now I may be miles off the mark here but I'm under the impression that the heater locked fault is due to an incorrectly entered security code at some point in the cars life, so I was expecting me entering the correct security code to solve it. Or is the heater locked due to the coolant temperature fault? Having had a quick search through the forum it appears that the G241 sensor is buried in the Webasto itself and needs to be replaced and may be more hassle / cost than it's worth to try and rectify! Although contrary to that, Self Study Programme 280 says that it can be unlocked again. Sorry for the somewhat rambling questions, I'm still trying to get my head around understanding VCDS / doing adaptations. Attached is the VCDS scan for this controller.

Thanks in advance,

Elliot.



Address 18: Aux. Heat Labels: None
Control Module Part Number: 3D0 815 005 AG
Component and/or Version: Standheizung 2426
Software Coding: 
Work Shop Code: WSC 01065 000 00000
VCID: 629C5830A85CEBF71E1-5160
2 Faults Found:

02251 - Heater Unit Locked 
000 - - 
01488 - Sensor for Coolant Temperature; Aux. Heating (G241) 
001 - Upper Limit Exceeded


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## n968412L (Apr 23, 2009)

Hi - might be worth trying to clear the faults - I think to do this you have to put "1" in Channel 3, and then clear the fault codes.

I've certainly done this in the past and it worked... but that was I think I'd forgotten to put the zero in channel 4. It's so long ago I can't quite remember the exact sequence... but this is all the info I had and I managed it.

If there is a genuine hardware fault, it won't help. But if it's a spurious error... well it's worth a try.

Good luck.

M


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## Elliot-Lowndes (Sep 6, 2015)

n968412L said:


> Hi - might be worth trying to clear the faults - I think to do this you have to put "1" in Channel 3, and then clear the fault codes.
> 
> I've certainly done this in the past and it worked... but that was I think I'd forgotten to put the zero in channel 4. It's so long ago I can't quite remember the exact sequence... but this is all the info I had and I managed it.
> 
> ...


Perfect thanks. Certainly worth a try, it’s not working ah the minute anyway so can’t make it any worse! Will give it a try and report back. 

Elliot.


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## robbie-rocket-pants (Mar 25, 2012)

This is the sequence I use:

Using a VCDS cable the access code for the webasto parking heater, module 18 , is 22106.

Adapt channel 09 to value 2
Adapt channel 04 to value 0
If the heater locks up (after too many start-failure attempts) adapt channel 03 to value 1 then clear the fault codes


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## Elliot-Lowndes (Sep 6, 2015)

Thanks gents, adapting channel 03 to a 1 unlocked the heater unit but the temperature sensor fault wouldn’t clear. Tried running it a few times and it started whirring away. A hand under the exhaust showed it was just blowing cold air and it locked up again as expected after a few minutes. 

Elliot.


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## PhaetonGP1 (Jun 16, 2019)

Hi, I'm in exactly the same boat here. 2008 Phaeton 3.0 tdi webasto aux heater locked. Last temp was 300°f I clear codes but this one is still there. Cant reset the locked heater. I'm using an Autel MD808 pro all system full diagnostic machine. I'm presuming I can do the 1 to 3 code changing on here but have no idea what you are referring to or on about when you say it. Please elaborate a bit further what I should do? Into auxialiry heater, Live data, then I choose channel 1-500 odd I press on for 1. It takes me to all this info but I cant change or click anything from here. Do I need actual VCDS? Would a normal (decent obd2 tool not work? thanks in advance.


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## robbie-rocket-pants (Mar 25, 2012)

Suggest you get a VCDS. Then you will know what we're talking about 🙂


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