Fabia evap temp sensor - how to (with pics)

[jonboyuk]

Bugger! I do have a VAGCOM but it's a bit iffy on Windows 7 :(

[jonboyuk]

Okay I've done it! Won't know if it works until we get another 25degs day! Anyway, for those who haven't done it, taking it apart is EASY. Putting it back together is a nightmare!!! Trying to find the small hole to stick the sensor in was hard.

Anyway, it was requested a while back that someone takes a picture of the back of the ECU so others can understand how to take it off. As someone else described, just push a flat-headed screwdriver down along the middle and it will loosen the catch. Then push the whole unit up! Needless to say I didn't so much as snap a single lug in the process, so without further ado, here is the photo. Hope it helps someone anyway. I'll let you know this fixes my car.

Cheers, Jon

Edited 3 June, 2009 by jonboyuk

[Candanga]

Okay I've done it! Won't know if it works until we get another 25degs day! Anyway, for those who haven't done it, taking it apart is EASY. Putting it back together is a nightmare!!! Trying to find the small hole to stick the sensor in was hard.

Anyway, it was requested a while back that someone takes a picture of the back of the ECU so others can understand how to take it off. As someone else described, just push a flat-headed screwdriver down along the middle and it will loosen the catch. Then push the whole unit up! Needless to say I didn't so much as snap a single lug in the process, so without further ado, here is the photo. Hope it helps someone anyway. I'll let you know this fixes my car.

Cheers, Jon

Lol +1 :P

Replaced my sensor yesterday. Broke only one pin of the ECU holder (shown up). Had to struggle A LOT trying to unplug the sensor (not yo remove it from the invisible hole). The same connector has a strange mechanism which requires at least 2 fingers in order to remove it.

My advise is to study the connector "mechanism" of another plug, like the ones the light system have (previously removed, near the can-cooler tube), and check how it works.

Space is very limited up there and I could only used half of the fingers of one hand. lol. I drive a left-side wheel, prolly is the same, prolly not. As for trying to find the hole wasnt that hard, use your finger as a guide (yeah.. sounds kinky but it works), and when u feel a little "rectangular" notch, blindly insert the sensor carefully in that area.

just my 2 cents.

Cheers!

[skomaz]

Just thought I'd post to say a massive thanks to Ap0gee for the guide - finally did mine today in an hour and it works a treat!

My only addition would be to make sure you unplug the correct thing (I tried unplugging the dash dials instead as I was looking too high up!)

The wires on the plug leading to my evap sensor were bright green so easy to see (once you know what you are looking for.

Also the plug was easy to undo - simply pinch the two tiny tabs, top and bottom, on the back of the plug.

And finally - if you struggle withone hand to get at things try the other - I found some bits were easier to reach and take out/put back left handed and some right handed.

[jonboyuk]

I completely forgot to update - but the new sensor fixed the AirCon perfectly! Good times

[fabia_owner_2004]

Replaced the sensor and problem cured! Many thanks.

A hint about removing the central locking ECU and bracket:

The bracket has 2 L - shaped lugs on the back that locate in 2 triangular holes in the metalwork. Hold a broad bladed screwdriver against the narrow end of the bracket nearest you where it meets the metalwork and gently tap the bracket upwards - the bracket should then slide out of the holes. Once you have freed the bracket, the ECU just slides out.

The sensor is then seen lurking above where the ECU was - look for a pair of green wires. And yes - it is a total pain getting the plug off the sensor!

[mark.r.cullen]

Thank you for the excellent guide. Briskoda is a great place! Parents air con stopped working so have just now replaced this sensor. £19 odd from the dealer (with a tiny 5% discount as I am a regular heh).

Removing the bracket was pretty easy, a flat head screw driver wedged in the middle did the trick, then just push up.

Found that removing the plugs from the back of the central locking unit was the most difficult part to be honest. Helps to tilt the seat right back and lay under there, or even take the seat out perhaps. There's 3 plugs on the back and on one side there's the little release clip. Ended up getting a screw driver to release the clip and pulling at the plug.

Air con now seems to work again. Only now I find out it's never worked in fan position 1. Seems fine in 2, 3 and 4. Might have to replace the control unit as per http://briskoda.net/forums/topic/112621-fabia-heater-air-con-control-panel-replacement-how-to-with-pics/page__view__findpost__p__1411327__hl__air+con+fan__fromsearch__1 perhaps? Though I am not sure they're overly bothered...

Again, many thanks!

[citroenzx]

Thank you for the excellent guide. Briskoda is a great place! Parents air con stopped working so have just now replaced this sensor. £19 odd from the dealer (with a tiny 5% discount as I am a regular heh).

Removing the bracket was pretty easy, a flat head screw driver wedged in the middle did the trick, then just push up.

Found that removing the plugs from the back of the central locking unit was the most difficult part to be honest. Helps to tilt the seat right back and lay under there, or even take the seat out perhaps. There's 3 plugs on the back and on one side there's the little release clip. Ended up getting a screw driver to release the clip and pulling at the plug.

Air con now seems to work again. Only now I find out it's never worked in fan position 1. Seems fine in 2, 3 and 4. Might have to replace the control unit as per http://briskoda.net/forums/topic/112621-fabia-heater-air-con-control-panel-replacement-how-to-with-pics/page__view__findpost__p__1411327__hl__air+con+fan__fromsearch__1 perhaps? Though I am not sure they're overly bothered...

Again, many thanks!

[citroenzx]

As everyone has said - an excellent guide. A few notes from me to anyone thinking of doing the work:

As suggested by someone earlier - take out the driver's seat - 4 bolts 4 minutes - this allows you to lie on your back on the car floor and look up under the steering column.

Get a head mounted LED torch - allows you to see what you are doing whilst using your hands.

Unclipping the central locking ECU carrier is easy if you reach up behind it through the hole in the mounting and push the locking tab towards the ECU with a finger whilst pushing the carrier towards the front of the car, and upwards to unclip it.

Take the ECU out of its carrier but do not unplug it. I found unplugging impossible but then discovered that I could get at the sensor by just moving the ECU out of the way. Two bright green wires, so you can't miss it. Unplug it before pulling it out - you can't unplug it when it is not captive.

I measured the resistances of the new sensor before putting it in place. For those who can solder, who are into electronics, and like to save cash, here are the readings: 4.5 centigrade 7.2k ohms, 4.8 centrigrade 6.67k ohms, 20.5 centrigrade 3.33k ohms. This looks like the RS code 697-4566 at a cost of £1.85 or the Farnell code 1888077 at £1.45. The cost of my new sensor from the VAG parts shop was £22.

Including vacuuming the floor under the seat where you can't normally reach the whole job took less than 2 hours. Best of Luck

[garethw]

Thanks for an excellent guide, managed to fix the sensor on my dad's car in about an hour and a half.

[DaKKs_152]

Jesus! You lot totally had me confused for a while there. I disassembled the dash, and there was nothing there. I really have to start keeping track of which of my cars are left and which are right hand drive. This is getting bloody ridiculous. Of course, I didn't read the entire thread either. Worst thing is that I can't even blame alcohol for this...

Edited 31 March, 2012 by DaKKs_152

[VWSverige]

HI Gents,great info and tips. I mean, this is either getting many bad machanics out of a job or realising that they have to get their act together! LOL. In Sweden it would basically take you maybe months looking for a correct diagnose of the problem still not fixing it. These Forums are worth GOLD! Green gold for this matter. I have spent many hours reading this and solved many issues and planned even more adaptations on my simple Kombi or Station as you might call it. The future is limitless! Ans on a budget aswell! YES!

The reason I react on the specific forum is that I would like to know which part number does the Evab sensor have? Without this I will never get a proper part as the whole issue is not known to the local and nearest to the local dealer! Maybe they want to ignore and prefer tochange my newly refilled and exchanged compressor! It works fine, my AC but sometimes it goes bannas for about 5 to 10 minutes going from a 18 degrees to maybe 35 in a matter of seconds! Seems like a typical EVAP issue. So please help and post the part number needed.

Cheers for this a future posts!

[Tech1e]

Sounds more like a temp flap motor to me.

The evap sensor is only there as a safety measure, it monitors the temp of the evaporator so if it gets to cold it can shut the AC off to prevent it freezing.

[VWSverige]

Techie, I connected a OLD freware version of VAG Ross Tech and indeed i fished out something like a valve not properly closing in one of the AC modules. Is this a direct swap? Do you happen to have any part number?

Appreciate your imput!

And Again, GREAT INFO IN THIS SITE!

Ha det bra! (meaning : have a good one!)

[thrope]

Just another thanks... Succesfully followed the guide this afternoon. I'm usualy rubbish at car stuff, especially when there is trim involved, but managed to complete this without too much trouble and everything went back together perfectly!

 

Trickiest parts for me were the general awkwardness of lying under the steering wheel, reattaching the can cooler pipe but mainly actually getting the new part in - I got the old one out pretty easily with a bit of wiggling but completely lost track of where the hole was or which direction the twist should be, so to get it back in I had to get a torch and a small mirror - even then it was pretty hard. But once it went it was fine.

 

AC working perfectly. For reference I need a T15 and a T20 (first two screws are T20)

 

Thanks again

[carlos777uk]

Really looking forward to trying this as I'm sure this is my problem too.  I just had my aircon regassed and the garage claimed it worked perfectly when they did the work - in the morning.  The only other time it's worked is - in the morning!  I.e. when it's cold.  

 

One thing though, I can't find this part?!  Eurocarparts don't have it and eBay is drawing an odd blank right now.  Anyone suggest somewhere please?

 

EDIT: Found it on eBay by searching "EVAPORTATOR HEATER SENSOR 6Q0907543D"

Edited 17 July, 2013 by carlos777uk

[carlos777uk]

Ap0gee you Sir are a legend for making this guide.  My aircon now works perfectly and I certainly would simply have gone without (rather than pay garage fees) otherwise.  In return I'd like to offer a photo that may helps others in knowing where the temp sensor is.  You might like to include this in your pdf?  Up to you

 

I'm on my back here looking up and, as you can see, I didn't remove the central locking unit as I simply couldn't get the cable header out.  My version had a sliding mechanism rather than lugs.

 

I broke the old sensor in removing it as it was just far too difficult to remove the wires in something that's held in by friction only.  A very frustrating part of the process - be prepared to come away with scratches all over your wrists here!!  My big tip for the whole job is how you put the new sensor back in.  Position the whole thing past the hole and then come back down... don't try to insert it from the driver footwell area!  Also, it goes in with the point of the bend towards the sky if that makes sense.  I did it the wrong way around at first and very nearly got it stuck and broken trying to remove!

 

I'd absolutely endorse removing the car seat too.  4 x M10 splines, 5 minute job.

 

 

[Breezy_Pete]

Because it's so hard to get a view of what you're doing down there, I found it took me a while to find the hole that the sensor came out of, when I went to fit the new one.

 

Hopefully this photo of the right hand side of the heater box assembly might help:

 

 

 

And here's one with the sensor half way out of its location to show the hole you're looking/feeling for when replacing.

Edited 29 June, 2018 by Wino
pic fix

[MiroslavYordanov]

Hello,

 

Yesterday i used service to diagnose the problem. And should be the evap temp sensor. In Sunday (for a first time) i will try to do it on my own way, because in the services they ask me around 150 euros for this. 

Hope to fix the problem soon and will reply :).

Hope this thread will help me..now is 39 degrees =)

[tigerbiker]