MFTS function and substitution

[Rusty]

As I understand it, the MFTS provides 2 functions: the first is to supply the cluster with a temperature and the second is to provide an over-temperature cutoff when coolant temps exceed 120degC.

Are there any more functions?

I've had a bit of a thought about ditching the extortionately priced item and replacing it with either just a temperature sender and thus sacking off the water temperature boost cut function that any driver who looks occasionally at the gauge could do themselves, or with the addition of a secondary warning light / thermo switch to do the job.

So, is there a temperature sender that has the same resistance profile as the MFTS?

[_ShurikeN]

I use 049 919 501 instead of 034 919 369 C as a sender for the cluster. In my case it is mounted on the cylinder head directly, but It can be installed to a proper place, If needed and If there is some spare time.

[Rusty]

Any more details on that one? Picture? Cheers

[_ShurikeN]

Can't take detailed pictures now, lots of images if googling "049919501".





It is used on old engines KV/MC etc., It has M10x1 thread, on my NG it is screwed into a blank casting with thread with a very slight modification of harness (an extra wire from a proper contact of 4-contact 034 919 369 C).

Did not find out about how this ''spike" would affect an A/C or climate, if there is one.

[Rusty]

Thanks

Just need Dave to link to an info thread...

[Rusty]

Managed to find a link

http://forums.quattroworld.com/s4s6/msgs/22584.phtml

I think getting the above temp sender makes a lot of sense for anyone who can read a temp gauge.

[UrS4boy]

Managed to find a link http://forums.quattroworld.com/s4s6/msgs/22584.phtml
I think getting the above temp sender makes a lot of sense for anyone who can read a temp gauge.

I would have given you the link about 45 min ago but the website where key photos and diagrams used in the F76 MFTS post is down/malfunctioning. The owner of the server has been alerted and is attending to the issue.

While I am here I will state that avoiding the proper MFTS is less than smart. It does have multifunctions that the Audi engineers spent sometime thinking about and implementing. If they thought at simple single pole temp sender was enough, that's all they would have given us. Deleting the MFTS to save a few bob is dumb. (IMO).

[Rikki Kitto]

It's just really upsetting when a modern car MFTS costs £30 and ours costs £120

[Rusty]

Diplomatic as ever

What does it do though? On an ABY, the above link states that it has 2 functions, one of which is pretty much redundant on a car with coolant in it in a temperate climate. Equally, on a car with no AC, it has almost no function either.

It's hardly dumb to replace something that's known as a problematic item, even when new with some items(!), with something that will not malfunction. It also removes the equally problematic 4 pin plug, again, something that could cause mis-reading on the temperature gauge, which is 1001 times more important than an over-temp boost cut that occurs at almost unobtainable coolant temperatures.

[Rusty]

From what I can see, the thread on the MFTS is M14x1.5, so an adaptor would be required but that's hardly an issue.

What other MFTSs are there? what about using one of those instead and retaining the almost redundant safety features?

[Rusty]

Custom Auto Craft do them for 32 euros...

[Rusty]

M10x1 to M14x1.5 adaptor on ebay for £6 - http://www.ebay.co.uk/itm/OIL-TEMP-S...-/130564308937

[UrS4boy]

Diplomatic as ever

I said "IMO" (in *my* opinion). As a engineer, I tend to have at least some confidence that the engineers involved with the development of the AAN, ABY and ADU thought certain safety features should and could be built into the MFTS and its signal to the ECU, etc. If you think you are smarter than those engineers and don't need those safety features, then go ahead with the single pole sender.

[andy10v]

Is the signal the dash the same as the signal to the ecu?

[Error404]

I said "IMO" (in *my* opinion). As a engineer, I tend to have at least some confidence that the engineers involved with the development of the AAN, ABY and ADU thought certain safety features should and could be built into the MFTS and its signal to the ECU, etc. If you think you are smarter than those engineers and don't need those safety features, then go ahead with the single pole sender.

Sure but don't forget the car was built for many, many markets and has to function in every climate and all conditions and they must consider every eventuality - i.e. Complete retard giving it full death in 35deg heat with the coolant temp warning lamp flashing at them. Consequently in some geographical locations not all features are really that relevant for us seasoned and careful owners, this high temp boost cut being on of them (IMHO)