# Anyone here changed their G201/G214 brake pressure sensors?



## silverbug (Jan 1, 2020)

So it looks as if my brake pressure sensor(s) on the master cylinder are playing up.
The ESP light came on last week and after scanning it with VCDS the code P01435 Brake Pressure sensor 1 (G201) Intermittent electrical fault was found.
Having checked the measuring blocks for the G201 switch the pressures were bouncing around with the brake pedal depressed so I'm fairly certain the switch is faulty, it seems to be in the early stages of failure though as turning off the ignition and re-starting clears the ESP light.
This brings me to my question , the plan is to DIY replace both switches with Genuine items and to carry out a full brake bleed, so how much of a pig is this job?
I know all the reservoirs for coolant , PAS and other stuff in that area need to be drained or at least moved out of the way , but have just read an old thread on here about removing the engine mount and jacking up the engine just to get access?
Having done all that on a recent cam belt change I don't really want to go through all that again .
I'd appreciate any pointers from someone who has done this themselves .
Thanks!


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## PlasticMac (Apr 25, 2017)

My local indie did both of mine last year. He rated it as a PIA, and his workshop is very well equipped. Cost was £482, inc parts and vat.
Mac.


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## silverbug (Jan 1, 2020)

PlasticMac said:


> My local indie did both of mine last year. He rated it as a PIA, and his workshop is very well equipped. Cost was £482, inc parts and vat.
> Mac.


Thanks for the info ....
Genuine sensors are £80 each so it'd cost me £160 plus the cost of brake fluid and my time.
I hate paying anyone to do work that I can do myself, it's just I'd like to really know if it's a nightmare job before I attempt it.
I felt the same way before doing the cam belt and water pump , and that worked out fine.


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## BrianB (Apr 15, 2016)

I believe DC240S replaced these on page 40 of his build thread, worth a look.


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## silverbug (Jan 1, 2020)

BrianB said:


> I believe DC240S replaced these on page 40 of his build thread, worth a look.


Thanks , came across it earlier whilst searching for info and it does make it look very doable.....


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## John949 (Apr 12, 2017)

I did it on a friend's car and I'd rate it about a 7 (out of 10). You have to remove the plastic shroud round the fuel / evaporative emission pipes (don't get them mixed up) and then it's not too bad. His car wasn't a 225 though so it may not be quite the same - the charge pipe will have to come off for starters.


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## DC240S (Sep 24, 2014)

I was quoted approx £500 to change both sensors at an Indi - DIY cost me nothing - in fact I made a profit with the sale of surplus OE sensors (bought 4x genuine for £10 ea. from a VAG dealership).

Entirely possible as a DIY job - buy the parts/tools you'l need in advance and recommend a pressure bleeder like the SEALEY one I used.

Buy a replacement securing bolt for the reservoir as engaging that in the thread is perhaps the fiddliest job and its likely you'l drop it - think mine fell into the hole in the chassis box section! - I had to then wait a week for a replacement!

https://www.ttforum.co.uk/forum/viewtop ... &start=675


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## silverbug (Jan 1, 2020)

John949 said:


> I did it on a friend's car and I'd rate it about a 7 (out of 10). You have to remove the plastic shroud round the fuel / evaporative emission pipes (don't get them mixed up) and then it's not too bad. His car wasn't a 225 though so it may not be quite the same - the charge pipe will have to come off for starters.


Thanks , that reassures me , certainly seems within my capabilities  .



DC240S said:


> I was quoted approx £500 to change both sensors at an Indi - DIY cost me nothing - in fact I made a profit with the sale of surplus OE sensors (bought 4x genuine for £10 ea.).
> 
> Entirely possible as a DIY job - buy the parts/tools you'l need in advance and recommend a pressure bleeder like the SEALEY one I used.
> 
> ...


Thanks, you did well to get those sensors for a mere tenner , the cheapest Genuine I could find were £80 each  .
No way am I going to fit repros off eBay as they all seem the same items from China , just at different prices.
Sadly the reservoir securing bolt appears to be NLA.
I see from your thread that you only bled the master cylinder , front calipers and clutch?
Did you not do the ABS pump bleed?
That looks a worse job than the sensors :lol: .
Lastly, Bentley says the torque for the sensors is 10ft/lbs , is there space to get a socket/torque wrench in there or do you have to guesstimate and did the new sensors need calibrating with VCDS once fitted?
Thanks .


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## davebowk (Aug 16, 2019)

This looks genuine £39 message them to check https://www.ebay.co.uk/itm/FOR-VW-AUDI- ... Sw3-Be-OFq
Another one same price https://www.ebay.co.uk/itm/VW-AUDI-SEAT ... Swc5Jd07Yo


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## DC240S (Sep 24, 2014)

silverbug said:


> Thanks, you did well to get those sensors for a mere tenner , the cheapest Genuine I could find were £80 each  .
> No way am I going to fit repros off eBay as they all seem the same items from China , just at different prices.
> Sadly the reservoir securing bolt appears to be NLA.
> I see from your thread that you only bled the master cylinder , front calipers and clutch?
> ...


Use genuine sensors supplied from TPS or VAG dealership or other confirmed VAG source - there are some convincing chines copies on eBay.
Strange on the bolt - have you tried Coverdale parts?
No need to bleed the ABS pump - there was a reason as I remember - perhaps because the system is bled before and the unit isn't cycled through the process?
Torque was indeed approximate - no access for the torque wrench I have.
No VCDS calibration required - just a code scan and clear down.

DC


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## silverbug (Jan 1, 2020)

davebowk said:


> This looks genuine £39 message them to check https://www.ebay.co.uk/itm/FOR-VW-AUDI- ... Sw3-Be-OFq
> Another one same price https://www.ebay.co.uk/itm/VW-AUDI-SEAT ... Swc5Jd07Yo


Thanks, I saw those but I *think* they're Chinese, having seen them for £13 on AliExpress I'm of the opinion that all the cheap ones on eBay are Chinese.
I've gone for 2 from Stafford Audi , via eBay again but at £80 each by far the best price I could find , for Genuine Audi/ATE at least .



DC240S said:


> Use genuine sensors supplied from TPS or VAG dealership or other confirmed VAG source - there are some convincing chines copies on eBay.
> Strange on the bolt - have you tried Coverdale parts?
> No need to bleed the ABS pump - there was a reason as I remember - perhaps because the system is bled before and the unit isn't cycled through the process?
> Torque was indeed approximate - no access for the torque wrench I have.
> ...


Thanks that's really useful info , I'm going to get one of those Sealey gizmos you mention , I do have an Ezibleed but the Sealey looks much better.
It is odd about the reservoir bolt (1J2 611 353) , I was given a price this morning at my local VW main dealer so I ordered it, but they rang me soon after to say it was no longer available.
I have found it on the internet in Lithuania & Slovakia but with carriage included it would cost £20-25 which is insane for a single bolt.
I've just bought a cheap s/h master cylinder and reservoir off eBay with the bolt included for well under that, so it's sorted :mrgreen: .
Am feeling a lot more confident now about doing the job , thanks again  .


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## DC240S (Sep 24, 2014)

silverbug said:


> Thanks that's really useful info , I'm going to get one of those Sealey gizmos you mention , I do have an Ezibleed but the Sealey looks much better.
> It is odd about the reservoir bolt (1J2 611 353) , I was given a price this morning at my local VW main dealer so I ordered it, but they rang me soon after to say it was no longer available.
> I have found it on the internet in Lithuania & Slovakia but with carriage included it would cost £20-25 which is insane for a single bolt.
> I've just bought a cheap s/h master cylinder and reservoir off eBay with the bolt included for well under that, so it's sorted :mrgreen: .
> Am feeling a lot more confident now about doing the job , thanks again  .


As I mentioned in my thread when removing the reservoir try to avoid accidentally pulling the rubber clutch fluid supply hose away from the bulkhead hard pipe - its well hidden behind the aluminium heat shield which needs to come off to re-attach/clip - that's a real faff!

DC


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## silverbug (Jan 1, 2020)

DC240S said:


> As I mentioned in my thread when removing the reservoir try to avoid accidentally pulling the rubber clutch fluid supply hose away from the bulkhead hard pipe - its well hidden behind the aluminium heat shield which needs to come off to re-attach/clip - that's a real faff!
> 
> DC


I shall definitely take great care , thanks!


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## silverbug (Jan 1, 2020)

Well can't fault Stafford Audi , ordered sensors very late on Monday night and they arrived this morning 8) .
Nice fresh stock too, these ATE sensors are a dark gun-metal colour, nothing like the silver-coloured supposedly OEM ones on eBay......
Just need to find time to do them now ......


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## DC240S (Sep 24, 2014)

Nice! Will be very satisfying when completed


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## silverbug (Jan 1, 2020)

DC240S said:


> Nice! Will be very satisfying when completed


Definitely, I think the fault has been there ever since I purchased the car in February as VCDS threw up a faulty brake light switch code (since replaced) which I now think was a manifestation of the pressure sensors beginning to play up.
There doesn't seem to be any logic to when the ESP light will come on now , it did appear to get worse on really hot days but now it seems random.
The sensor(s) gave wild pressure readings the first time I checked measuring block 5 with VCDS but after a long journey yesterday with an extremely hot engine bay (and no ESP light) the sensors tested fine :roll: .
Time will tell if this really sorts out the ESP light issue but I'm quite confident it will as at least one of the current brake pressure sensors is dodgy.


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## silverbug (Jan 1, 2020)

I've got all the parts and tools required now to do the job, plan is to change the sensors early next week.
Seeing as how access is so tight in there, I plan on removing the reservoir as per DC240S's thread.....

DC240S; can I pick your brains with regard to the hydraulics please?
Did you just whip off the old sensors and screw the new ones in, or did you try and fill the new sensors with a drop of brake fluid prior to putting them in (there seems to be enough room to get fluid in there..)?
When it comes to bleeding what order did you do it in?
I'm guessing :
Master cylinder bleed nipples 
Front left calliper 
Right front caliper
Clutch

Lastly , I gather from your thread that you didn't need to do an ABS pump bleed?
I'm really hoping that I don't either!

Thanks!


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## DC240S (Sep 24, 2014)

silverbug said:


> I've got all the parts and tools required now to do the job, plan is to change the sensors early next week.
> Seeing as how access is so tight in there, I plan on removing the reservoir as per DC240S's thread.....
> 
> DC240S; can I pick your brains with regard to the hydraulics please?
> ...


After syringing as much fluid from the master cylinder as possible (with workshop tissue underneath for spillage/dripping), I just removed old sensors and replaced with new. 
Yes - bled master cylinder first - then clutch IIRC then callipers. Didn't need to bleed ABS as this remained a closed circuit during process. To 100% remove old fluid and any air suspected in the system - yes bleed the ABS.

Thats as I understand/did - I may be corrected.


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## silverbug (Jan 1, 2020)

DC240S said:


> After syringing as much fluid from the master cylinder as possible (with workshop tissue underneath for spillage/dripping), I just removed old sensors and replaced with new.
> Yes - bled master cylinder first - then clutch IIRC then callipers. Didn't need to bleed ABS as this remained a closed circuit during process. To 100% remove old fluid and any air suspected in the system - yes bleed the ABS.
> 
> Thats as I understand/did - I may be corrected.


Great stuff , thanks for the extra details !  .


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## silverbug (Jan 1, 2020)

Well I've come to an impasse  .
I just can't remove this cradle thing to get at the sensors , I've managed to wiggle it free of a stud so it moves side to side an inch or two but there's no way I can get my hands or any tools in there as it is  .
The screw holding the reservoir on is on this side too so until this cradle is out of the way I'm stuck.
I did manage to half unclip the lid on this thing then decided that it didn't serve any purpose and so replaced it, fearful of breaking those pipes I've downed my tools  .
Does it undo from below?
I haven't removed the engine under tray because I was hoping not to have to go to all the faff .


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## silverbug (Jan 1, 2020)

I should have Googled it first  .
Just found a video explaining Golf master cylinder removal which shows it , around the 2 mins 50 secs mark.....


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## DC240S (Sep 24, 2014)

silverbug said:


> I should have Googled it first  .
> Just found a video explaining Golf master cylinder removal which shows it , around the 2 mins 50 secs mark.....


Yep - it all unclips - patience is key - go slowly.


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## silverbug (Jan 1, 2020)

Thanks DC240S.
Once you know how, that cradle thing does come apart quite easily.... that video was so useful.
New sensors installed but alas my crows foot wrench won't fit in there so I had to guesstimate how tight to do them up.
I actually chickened-out and chose to leave the reservoir in place.
Just putting things back together now and then to bleed everything.....


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## silverbug (Jan 1, 2020)

All finished and I think successful 8) .
Tested the new sensors with VCDS and the pressure readings from both new sensors are near identical  .
Time will tell if it has really fixed my ESP light problem but the omens are good that it has  .
Thanks to everybody who's helped me on this thread and especially DC240S!


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## DC240S (Sep 24, 2014)

Glad I could help! It's what the community's for.


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## silverbug (Jan 1, 2020)

Thought I'd post an update in case anyone else has to do this job in the future .
All totally DIY-able with only basic tools.
TBH having done it , I don't really get the "pig of a job" label :? .
The trickiest part of the whole job for me was screwing in the new sensors ( taking great care not to cross-thread them!) but nothing was really difficult at all?
It took me an entire working day to do (8.30am -5pm) but that included lots of down-time when I couldn't figure out how to remove the fuel pipe assmbly/cover and general faffing around on my part  .
I reckon I could do it again in 3-4 hrs or less .
Have done almost 300 miles in the car now since doing the job and no ESP lights have come on, just did another VCDS scan and there's still no fault code in the ABS system so I'm very confident that it is fixed.
I wouldn't have been able to do it without DC240S's excellent guide but I did deviate slightly ....
Even though I did buy the master cylinder bung seals to allow removal of the master cylinder reservoir because DC240S had issues with pulling off the clutch line accidentally I decided in the end to leave the reservoir in place .
I used a large syringe to remove as much brake fluid as possible from the reservoir and once the coolant tank had been removed it created a lot more space to work in .
The PAS fluid reservoir was just moved out of the way with a few cable ties , nothing needed to be disconnected .
Once the space around the master cylinder had been created it was simply a case of undoing the brake pressure sensors (easy to undo as they really are not tight) and then allowing the brake fluid remaining to drip out .
I stuffed the best part of 2 x toilet rolls down underneath the master cylinder and this mass soaked up all the remaining fluid ( I wasn't in any rush) and once there were no drips I replaced both sensors .
I had purchased a crows foot spanner (27mm) to enable me to torque up the new sensors but with reservoir in place there was no way I could get it in there , I'm not 100% sure even with reservoir removed the crows foot spanner would have fitted ...
So I had to estimate the 10lbs/ft tightening torque using a ring spanner, it's not a high figure by any means.
Once the sensors were tightened up and the electrical plugs re-connected it was a simple case of just putting everything back together and bleeding the master cylinder , clutch and front calipers.
Using a pressure bleeder this was done very easily and I was rewarded with a nice clutch pedal and firm brake pedal at the first test drive out of the garage .
I'd definitely do this job again and wouldn't think twice about recommending others to do it themselves , the fact that I saved a few hundred £ is an even greater bonus  .


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## Lomondbob72 (May 29, 2018)

My local VCDS expert confirms that ESP light on because one of the brake pressure sensors has failed. I plan to replace both with new Audi items (£120 each!). I have cleared all the pipes etc which gives me access to the sensors but removing is a challenge. I reckon I need a 28mm ratchet spanner which has a canted end in order to gain access. Does anyone know if this is a good solution? If so then I'll need to ask my local garage if they can lend me one. Thanks Bob Sharp.


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## silverbug (Jan 1, 2020)

Removal of the old sensors when I did the job was easy , they really are not installed very tight&#8230;.
Can't remember now exactly what tool I used , whether it was a ring or open-ended wrench , but it was one of the two.
I mentioned 27mm as being the size of the sensor, am sure that is correct&#8230;..?


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## EddieMunster321 (Jan 14, 2016)

Lomondbob72 said:


> I reckon I need a 28mm ratchet spanner which has a canted end in order to gain access


That's how I did it; it's a twat of a job, that I did 3 times because I was stupid enough to ignore my own advice and not fit a genuine Audi sensor. When/if you use VCDS to recalibrate/bleed, remember that it can take 2-3 attempts to get it to work perfectly, particularly if you've changed the fluid (which you should really be doing) and wrestled with the cylinder and introduced air into the system.


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## fire88 (Jul 15, 2021)

Thank you so much for the information, it's time to get mine faulty Sensor replaced. 

Sent from my GM1900 using Tapatalk


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