# Successful EGT sensor repair saving £200



## milanonick (Sep 15, 2013)

Since buying our TT we have had the error 17863 - Exhaust Gas Temp Sensor 1 (G235): Implausible Signal displayed when checking for fault codes. Despite clearing the fault it would soon reappear.

I checked the physical connection to the sensor itself under the inlet manifold and confirmed it was secure and there were no signs of corrosion, so my next step was to replace the sensor. A quick call to my local Audi dealer got me price of £230 for a new one which is a bit steep in my opinion.

With a desire to keep my cash in my pocket I had a nosey around and came across this link to this forum which showed details on a fix for EGT by replacing the controller board inside it http://forums.fourtitude.com/showthread ... p=82539201

Mentioned in the thread is this company http://sidmotorsport.pl/pl/ who supply the replacement controller boards which come in at a little over £30 shipped to the UK. They do a couple of variants one for the S3/TT and the S4. After a few emails to the guys there my PCB arrived around three days after paying via Paypal.

Following the guide I opened my sensor up and removed the original PCB by de-soldering the posts at either end, two for the sensor probe and three for the connector. This left me with this.










The new board comes supplied with wires soldered on as opposed to sitting the board on the posts in the PCB housing box. Also the TT PCB housing is smaller than the one pictured in the forum link above.










I decided to cut down the three wires for the connector and leave the two sensor wires at the same length and soldered them to the appropriate posts. To avoid any shorts to the board I wrapped it in insulating tape which doesn't look the prettiest but does the job.










I then sat the board on the existing silicon that was in the recess and clipped the lid back on before refitting to the inlet manifold.

A few days on I have kept an eye out on faults being logged and am pleased to report that none have been logged. I have also checked the readings from the EGT in VCDS and they appear to be reported in an appropriate way.

Thought I would share this just in case anyone else has a similar fault and fancies trying a DIY fix. I appreciate that it won't cure EGT faults if there is an issue at the sensor end though.


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## Skeee (Jun 9, 2009)

Excellent work, well done.

Thirty quid _(plus postage and a bit of effort)_ against two hundred and thirty, is really a no brainer. 

You should link this thread from the How To list. viewtopic.php?f=56&t=172191


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## milanonick (Sep 15, 2013)

Skeee said:


> Excellent work, well done.
> 
> Thirty quid _(plus postage and a bit of effort)_ against two hundred and thirty, is really a no brainer.
> 
> You should link this thread from the How To list. viewtopic.php?f=56&t=172191


Thanks. I have added it as suggested


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## jamman (May 6, 2002)

Great work 

You can get OEM EGT sensors from ECP for less than £100 these days


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## Skeee (Jun 9, 2009)

jamman said:


> Great work
> 
> You can get OEM EGT sensors from ECP for less than £100 these days


 Now you tell him! Bit late James. :roll:


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## jamman (May 6, 2002)

Skeee said:


> jamman said:
> 
> 
> > Great work
> ...


I know mate but just shows what a bunch of robbing twats AUDI can be.

Still great work by the OP and quite satisfying I would think.


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## milanonick (Sep 15, 2013)

Skeee said:


> jamman said:
> 
> 
> > Great work
> ...


I didn't realise that ECP did them. Handy to know if the sensor side goes down on this one. It is nice a satisfying feeling to beat the system with this fix though :lol:


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## jamman (May 6, 2002)

milanonick said:


> Skeee said:
> 
> 
> > jamman said:
> ...


Too true mate and please don't think my post was belittling your effort in anyway because it wasn't meant that way at all.


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## milanonick (Sep 15, 2013)

jamman said:


> Too true mate and please don't think my post was belittling your effort in anyway because it wasn't meant that way at all.


Don't worry I didn't. I'm grateful to you for making me and others aware of the ECP alternative as if this one fully fails in the future I would rather pay their prices than the dealers.


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## sallyday10 (May 22, 2012)

Great piece of work!

Congratulations of your efforts.

Mike


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## emeye (Jan 18, 2010)

Thanks for this thread.

I am getting this error and can't decide which approach to take.

I can get a secondhand one for £50, or try this repair, but can anyone point me in the direction of a brand new one for £100 please?

By ECP do you mean eurocarparts.com? I couldn't find the egt sensor on there! I did get my MAF from them which worked out half the price of Audi!

Cheers.


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## emeye (Jan 18, 2010)

Well, to update, eurocarparts didn't have any, and the cheapest new one was just over £200!

Got a secondhand one off eBay for £30. Looks well used though. Not sure whether to swap out for the original or maybe open both up and swap electronic boards.


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## milanonick (Sep 15, 2013)

Seems that ECP don't have them available.

The fix I did is still going strong and I highly recommend it if it is something you are happy to tackle.


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## emeye (Jan 18, 2010)

Another update, hopefully to help anyone with a similar issue. I replaced mine with the secondhand one and all is now good and working.

If you have small-medium hands and arms, you can get your arm around the back of the engine from the right and use an open ended 17mm spanner to free the nut of the sensor and then loosen the nut fully off by hand.

I might be lucky, but my arms were long enough so I could see down the gap between the ARB to where the sensor goes while tightening it up. Had to cut the silver cable to get the old one out but just threaded the new one a slightly different way.

Got the lid off the old sensor electronics box lid easily enough, but removing the silicon was painful, especially trying to avoid damaging the circuit board and components.

If I had not already bought my secondhand sensor I might have considered replacing the board as the OP did, but while the box was still in the car.


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## manikm (Feb 17, 2014)

ok,

i need to fix my egt sensor issue (inplausible signal \ open short or something), s'been ongoing for ages.

ive managed to get hold of a 2nd hand EGT sensor (apparently without error codes) for £40 - i forgot about the polish place which does the replacement PCB for £30 ...so missed the boat there (OP first post).

but i was thinking, assuming that my problem isnt at the turbo end and its just a failed sensor PCB - if i could unbolt the sensor, i could de-solder the board from the one on my car, AND the 2nd hand one, and transfer the 2nd ones board into mine and solder it up.

my question is how do i unbolt the sensor? (pointed at here middle arrow)
http://www.wak-tt.com/mods/gauges/DSCN0056.JPG

also, a sub question, would i be able to feel \ trace the braided end going in to the turbo by hand \ eye to see if it has come loose - from the top of the engine, easily, without removing too much?

Thanks


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## asahartz (May 24, 2014)

The actual sensor is difficult to access, being on the exhaust behind the engine - the circuitry is in the box behind that plug arrowed in the centre.
Unbolting the sensor box is fairly straightforward - the black plate in that picture is attached by two bolts, roughly where the two outer arrows are in that image. be careful though, because that plate supports the dipstick tube which is notoriously fragile (mine came off OK though). The sensor box is bolted to the underside of the inlet manifold IIRC so is accessible once the plate is removed. You should be able to unsolder the wires to swap over the circuit board quite easily.

I'm assuming that's the only fault code you have - I had the same codes but there were others too which all turned out to be related. Fixing the root cause (a fuse!) saved me having to replace the EGT sensor.


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## manikm (Feb 17, 2014)

OMG!!! How hard is it to get the lid of the EGT sensor!! GRRRRRR!!!!

Still going....fighting it....


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## manikm (Feb 17, 2014)

i gave up in the end, these lids DO NOT COME OFF (easily)


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## fire88 (Jul 15, 2021)

I don't think mine has this EGT sensor in APX 2000.


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## David C (Apr 15, 2013)

fire88 said:


> I don't think mine has this EGT sensor in APX 2000.


Old post, but I think it is just the BAM 225 that has EGT.


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## fire88 (Jul 15, 2021)

Trying to learn from different people mate


Sent from my IN2020 using Tapatalk


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## Ascenity (7 mo ago)

Partially resurecting this thread to say that, 9 years later, Andrzej (sidmotorsport) still stocks these but they aren't listed on his website so you have to email him directly ([email protected]). I paid ~£38 (€36+€6 postage) for the EGT PCB & it arrived in just under 2 weeks.

I haven't actually soldered my board in yet as I managed to fix my OEM EGT board by removing the solder from the power/data pins either end of the board & flowing some new solder in place but if I see the "P1453 (P1455 now?) 17863" error code starts to appear again, I'll be sure to replace it with Andrzej board.


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