Aux Heater

[smitch]

It's that time of year and yes my 05 TDI aux heater is not working. Had a look under the car after the wife complained that the car was cold when it was 1c the other morning and I saw that the last part of the heater exhaust was missing. This is the bit from the little box on the exhaust. Took it to Frauds today for a diagnostic and they told me that it was working fine apart from the little bit of exhaust missing. I asked about error codes as i'm convinced it doesn't fire up and was told that it didn't generate any. There is definately no jet engine noise from the heater on cold mornings and hasn't been since the weather has turned. i also asked about a possible temperature sensor fault as i presumed they bridged the sensor to start the heater but was told everything was ok. Does anyone have any suggestions as it's not the quietest bit of kit when it works and i'm sure even with the bit of exhaust missing i would have seen/heard something to suggest it was coming on.

 

It would seem strange that if the dealer could have palmed a new heater off on me they would've so it's difficult to dispute what they are saying. Any advice gratefully received

[sotal]

Dealer probably didn't even know what it was,

 

You should hear the unit run, but I've had it where you can't really hear it over the radio/fans on full blast etc. Put your hand near the unit, they get very hot so you will feel the heat off the unit if it is running.

 

Don't think the exhaust will affect things.

 

Have you got access to VCDS to scan for faults yourself? If not it would be a good place to start, VCDS Lite is free and you just need a

[chrispb123456]

It's that time of year and yes my 05 TDI aux heater is not working. Had a look under the car after the wife complained that the car was cold when it was 1c the other morning and I saw that the last part of the heater exhaust was missing. This is the bit from the little box on the exhaust. Took it to Frauds today for a diagnostic and they told me that it was working fine apart from the little bit of exhaust missing. I asked about error codes as i'm convinced it doesn't fire up and was told that it didn't generate any. There is definately no jet engine noise from the heater on cold mornings and hasn't been since the weather has turned. i also asked about a possible temperature sensor fault as i presumed they bridged the sensor to start the heater but was told everything was ok. Does anyone have any suggestions as it's not the quietest bit of kit when it works and i'm sure even with the bit of exhaust missing i would have seen/heard something to suggest it was coming on.

 

It would seem strange that if the dealer could have palmed a new heater off on me they would've so it's difficult to dispute what they are saying. Any advice gratefully received

Hi there

The outside air temperature sensor which allows the starting of the heater is a simple make & break switch at 10 deg approx, if they did just bridge the terminals on the plug to the sensor and the heater worked OK, it may just be a simple job of changing the sensor.

Try bridging the sensor yourself (located on wiper linkage) remove plug from sensor then bridge the too wires in the plug, the heater should start a few seconds after starting engine if there are no other problems.

If it doesn't start you will need the assistance of a Vag-Com lead and laptop to interrogate the controller.

[smitch]

Thanks for the replies. Surely the dealer would have checked the sensor and does it generate a fault code if it malfunctions.i'm convinced it's not firing when it should as everytime i've used the car this week the temperature has been below 10c on the gauge

[chrispb123456]

Thanks for the replies. Surely the dealer would have checked the sensor and does it generate a fault code if it malfunctions.i'm convinced it's not firing when it should as everytime i've used the car this week the temperature has been below 10c on the gauge

Hi there

Don't beleive everything the dealers tell you, this is a simple task to bridge the sensor.

If then the heater doesn't fire for what ever reason that will generate a fault code.

 

Im not aware of the sensor leaving a fault code, if it is open curcuit the heater will still think it's summer time.

 

And definatly doesn't leave one if permanantly bridged.

[smitch]

I'll speak to the dealer when goes back on Monday for the exhaust to be changed. I don't doubt that the heater works, i suspect that for whatever reason it is not being told to fire. THe dealer actually said that the missing piece of exhaust might actually be making it work less efficiently. i would assume it would just be louder??

[smitch]

Quick update, had the scuttle plate out this morning and put a bag of frozen peas on the temperature sensor. Aux heater fired up with no excess smoke. Felt exhaust where piece was missing but couldn't feel a huge amount of hot air. The heater is definately getting hot but i suspect the missing exhaust(some of it's there,the last part isn't) is affecting the noise and flow. Interior warmed up when just sat at idle. I will see what happens when the new exhaust gets fitted tomorrow and what happens over the next few cold mornings. Is it worth me changing the sensor and are they expensive??

[chrispb123456]

Quick update, had the scuttle plate out this morning and put a bag of frozen peas on the temperature sensor. Aux heater fired up with no excess smoke. Felt exhaust where piece was missing but couldn't feel a huge amount of hot air. The heater is definately getting hot but i suspect the missing exhaust(some of it's there,the last part isn't) is affecting the noise and flow. Interior warmed up when just sat at idle. I will see what happens when the new exhaust gets fitted tomorrow and what happens over the next few cold mornings. Is it worth me changing the sensor and are they expensive??

Hi again

Interesting did you put the sensor in the bag of frozen peas or just on the outside :18: joking aside there is no link between the auxiliary heater air temperature sensor and the outside air temperature for the display on the dash this is located behind the lower edge of front bumper so allowances must be made when using the dash gauge as a reference for the heater sensor.

 

Also a point to note is that after a run when everything has fully warmed up if the car is switched off then restarted say 20 minutes later the heater will not fire straight away because the heat from the stationary engine has heated the area where the sensor's located (wiper linkage) even when temperature's around freezing, it will need a good blast of cold air around the sensor before it fires up again :)

 

PS, how much dealers rushing you for the exhaust?

[smitch]

Thanks for the reply, Frauds are stinging me for

[smitch]

Well picked car up today with it's new exhaust on the heater and despite me telling Frauds that I still don't think the heater's working sespite my last post and test of the sensor. They insisted it was. I drove it home with the coolant gauge at the bottom and the air temp gauge reading 7c and when I got home and felt the exhaust on the heater, it was cold. I phoned the stealer back and spoke to the Service Manager to complain. My overiding impression is that they haven't got a clue regarding these heaters. Below are the various statements made by the service manager and the technician I spoke to;

 

"They only come on when it's below freezing!" - service manager

"It's below 3c when they come on" - technician

"It should be below 10c" - me

"but it hasn't been that cold" - service manager

"When it was tested it was warm" - technician

"Did it have any fault codes?" - me

"Our diagnosis stuff doesn't really talk to them.It's VW stuff" - technician

"Well it will be warm because of the glowplug and coolant running through it. What about the exhaust was that hot?" me

"Well.....you probably need a new unit then" - technician

 

I can't see how they tested it as the scuttle plate clearly had not been removed for some time when I took it out so they clearly had not bridged the sensor and I suspect that they are not looking in the right place for the codes.

 

I despair, you take it to the people who should allegedly know and they are obviously completely clueless!! I have phoned another manager to complain and had a real go at the chap as all I want is a solution to the problem. The car is going back yet again tomorrow. This is their last chance, the so called three strikes and you're out!

 

The only difference is can find from when it was working last to now is that there is not a clicking from the front passenger footwell area when I start the car on cold mornings. Is this the dosing pump or a relay that I would've heard clicking?? The run on pump is definately working as i can hear it humming behind the dash.

[sotal]

The clicking noise is the dosing pump, don't go just on that though as you can't always hear it, I believe there was even a Technical Service Bulletin issued on how to fix the clicking noise, something to do with th eway the pipe is mounted

[Mirez]

The rapid tick-tick noise is the dosing pump, its controlled by the heater itself though so a lack of noise won't necessarily indicate the pumps dead but it does mean that, as suspected, the heaters not firing.

 

The problem with taking it to a Ford dealer is that as I've mentioned on other threads, the heater speaks VW and not Ford, so they can't communicate with it. That not only makes diagnostics much harder but also means they can't clear a lockout error (multiple re-occurrences of the same fault which shuts the heater off and won't reset when the faults corrected)

 

To half defend Ford - with regard the sensor bridging, they would more likely have fed a direct 12V feed into the connector down at the heater itself - it would be much easier then shorting out the sensor itself. The cost of the exhaust cost is also extremely steep but again you've not gone direct - Eberspacher (the manufacturer) will add their mark-up then sell the part to the VW group, who will have added their mark-up and then sold it to Ford, who will have added their mark-up and sold it to you and hence the cost.

 

Personally I wouldn't bother taking it back again, they are far too limited by communications and parts availability to fix it without ordering it as an assembly. A VW, Audi or Seat dealer would be a much better bet or any independent VAG specialist. Given the fact you've taken the scuttle panel off and got involved, I think you would be better advised to tackle the fault yourself - find someone local who had VAG-Com and can read the fault for you and clear any lingering errors - its one of the easier parts to get out and fiddle with :P

Edited November 22, 2010 by Mirez

[smitch]

Mirez, as usual, you are a goldmine of information.

 

I will speak to the garage in the morning and suggest that unless they have access to a VAG-Com, that I take it somewhere else. I am concerned that they will try and push the complete unit replacement front.

[gregers]

i would personally go down the route of saying to them THAT YOU WANT A REFUND on any money you have paid to them in diagnosing the fault/s obviousley your stumped with the cost of the exhaust THINK you will have to put that 1 down to experiance im afraid,

dunno how much it has cost you so far,but would think under the Supply of Goods and Services Act 1982 then they havnt actually found the fault.now there telling you you might need a new heater and thats after saying to you on 2 occassions EVERYTHING is working ok,clearly you have now found out the hard way that fords dont have a clue what there doing on these cars,hence why forums like this 1 was set up,there have been endless posts/threads on the subject of dealers chasing a problem for it to end up costing the owner a bloody fortune for it to turn out to be something that ended up being a simple fix.

good luck.

 

ive been down this route myself when i bought my car,posted all about it,and i had some dealings with my local fords,

i told them to get the parts from the vw garage opposite,we cant do that sir they wont be gaurenteed,WTF.

[smitch]

Gregers, thanks for the reply.

 

I intend to take the car back to Ford in the morning, see what they come up with and argue about money already paid. If they want to replace anything or do anything that doesn't involve properly reading any fault codes first, I won't let them and check it first myself by buying a Vag Com lead from Ebay and with advice from on here. I think I'll probably get the lead anyway as it seems a good investment for the future.

 

Rather naively, I expected Ford as a reputable company to have the correct diagnostic equipment to check the cars they produce.Still as you say, you live and learn. The exhaust for the heater was

[chrispb123456]

Hi Smitch

Sorry to say I told you so regarding dealers, very few have a clue on these vehicles.

You said in an earlier post that you thought the heater had fired after freezing the sensor with the peas, but only minimal heat from exhaust.

That would say to me the glow plug is getting hot but no fuel being pumped but not necessarily the fault of the pump itself as its controlled from the heater control unit which is part of the heater, there's been a few cases lately where the control units failed on the later MK2 heaters.

 

As Mirez said you really need Vag-Com on there and see what thats showing up.

You could check it yourself by getting a Vag-Com lead (ebay) and free software + laptop, or ask someone local, or if your really desperate you could pop down to Kent and I'll check it for you. :P

[sotal]

Gregers, thanks for the reply.

 

I intend to take the car back to Ford in the morning, see what they come up with and argue about money already paid. If they want to replace anything or do anything that doesn't involve properly reading any fault codes first, I won't let them and check it first myself by buying a Vag Com lead from Ebay and with advice from on here. I think I'll probably get the lead anyway as it seems a good investment for the future.

 

Rather naively, I expected Ford as a reputable company to have the correct diagnostic equipment to check the cars they produce.Still as you say, you live and learn. The exhaust for the heater was

[chrispb123456]

The rapid tick-tick noise is the dosing pump, its controlled by the heater itself though so a lack of noise won't necessarily indicate the pumps dead but it does mean that, as suspected, the heaters not firing.

 

The problem with taking it to a Ford dealer is that as I've mentioned on other threads, the heater speaks VW and not Ford, so they can't communicate with it. That not only makes diagnostics much harder but also means they can't clear a lockout error (multiple re-occurrences of the same fault which shuts the heater off and won't reset when the faults corrected)

 

To half defend Ford - with regard the sensor bridging, they would more likely have fed a direct 12V feed into the connector down at the heater itself - it would be much easier then shorting out the sensor itself. The cost of the exhaust cost is also extremely steep but again you've not gone direct - Eberspacher (the manufacturer) will add their mark-up then sell the part to the VW group, who will have added their mark-up and then sold it to Ford, who will have added their mark-up and sold it to you and hence the cost.

 

Personally I wouldn't bother taking it back again, they are far too limited by communications and parts availability to fix it without ordering it as an assembly. A VW, Audi or Seat dealer would be a much better bet or any independent VAG specialist. Given the fact you've taken the scuttle panel off and got involved, I think you would be better advised to tackle the fault yourself - find someone local who had VAG-Com and can read the fault for you and clear any lingering errors - its one of the easier parts to get out and fiddle with :P

Goodness Mark how big are your hands I have a job getting one hand in that gap by the heater!! :P by the way I did send you my email address have you received it?

[smitch]

The other bit on the bill for for the diagnosis and the fitting.

 

As expected, Ford did the whole "you need to replace the unit" at

[davewill]

The other bit on the bill for for the diagnosis and the fitting.

 

As expected, Ford did the whole "you need to replace the unit" at

[smitch]

The other bit on the bill for for the diagnosis and the fitting.

 

As expected, Ford did the whole "you need to replace the unit" at

[smitch]

Davewill,

 

Had an independant electro-diesel specialist recommended to me in Reading near where I live. They specialise in Erbarspascher and are having a look at the car this afternoon. I'll let you know what the score is. They can read about 95% of vehicles and won't charge if they can't. I'm hoping for a decent opinion on the issue.

[smitch]

Went to the specialist in Reading. He plugged in an Erbaspascher diagnostic machine straight into the heater and it wouldn't read any of the data on it. He then tried to access it via the VAG-com port under the dash and all it would register is a general fault with the ECU. He thinks that the ECU is completely corrupted. He checked the dosing pump by wiring it to a feed and it clicked away happily. His suggestion was to either replace the controller/ECU for about

[gregers]

SHOT IN THE DARK HERE,but does the run on pump work?

i know when mine failed the heater was spooling up and then cutting out,and it wasnt getting hot.

im probably clutching at straws here but have the codes actually been read and cleared?

ive gone over the thread again and cannot see any reference that they have,im just wondering whether

its had the 5 flame out errors and all thats needed is a reset.

still as youve got a lead on order then you an check yourself.

[davewill]

SHOT IN THE DARK HERE,but does the run on pump work?

i know when mine failed the heater was spooling up and then cutting out,and it wasnt getting hot.

im probably clutching at straws here but have the codes actually been read and cleared?

ive gone over the thread again and cannot see any reference that they have,im just wondering whether

its had the 5 flame out errors and all thats needed is a reset.

still as youve got a lead on order then you an check yourself.

 

 

Smitch / Gregers thanks for your help

 

Interesting one Gregers about the run on pump, as i am not sure if mine is working

When i switch off the car i hear a loud ticking sound from under the bonnet that lasts about 90 seconds. If i turn on the ignition there is no audible sound for the pump working

When i ran Vag Com and got the memory module controller error code, i cleared the 5 instances logged. Switched the ignition off, then started up the engine again. Checked vag com staright away and the error code was back

So, could it be the run on pump that has caused the failure of the Aux heater??

 

Smitch, i am in Reading on business about twice a month, so if you could post contact details for the Company you used, i will see if they can help me

 

Thanks again, Dave