Braking by itself!!

[jribeiro]

Hi
my Audi has started playing up recently! I'm driving roughly 15-20mph and the car will heavy brake by it self which causes it to skid. Luckily I'm going slow because if it happened whilst on the motorway could lead to a huge accident!!
has any one come across this fault?

any help is appreciated!!

 

[<tuffty/>]

Get the car scanned for fault cdes using VCDS... this should give clues as to whas happening but they only thing that could possibly affect the brakes this way is the ABS unit and this suggests faulty sensors or sensor wiring.. have seen simialer effects when a sensor wire was damaged and the ABS unit randomly kicking in...

A scan should indicate which sensor is affected

<tuffty/>

 

[colicabcadam]

seems very odd to me - servo seems to be acivating its self - i would not drive it anymore until fixed - any lights on the dash while it is happening ?

 

[jojo]

Wrong master cylinder? Didn't Welly have a problem with self braking on his S3 which destroyed a set of his brakes?

 

[Sevv]

mine did that until i changed my lateral and longitudenal sensor... i think the code is G202 not either 400 pounds cost me

 

[jribeiro]

No lights on dash or nothing. Will get car scanned today with a scanner fingers crossed its nothing bad!! Only had car a week!!

 

[George The Diesel Head]

I had a similar problem, turned out the ABS sensor wire had come off and fouled on the wheel. Get it scanned, pull the ABS fuse out in the meantime and just drive carefully!

 

[jribeiro]

Just got the car plugged in. I got 2 codes which were wheel angle sensor g202 and sensor for lateral acc g200. The g202 cleared but g200 didn't. Can anyone guide me in the right direction as to what the fault is and where the sensors are?
Thanks

 

[Sevv]

Just got the car plugged in. I got 2 codes which were wheel angle sensor g202 and sensor for lateral acc g200. The g202 cleared but g200 didn't. Can anyone guide me in the right direction as to what the fault is and where the sensors are?
Thanks

well mate as i told you, you need a new sensor as the one i bought that G202 sensor can come on at ANY time and that wierd braking will happen (if it does happen just control the steering wheel and put your foot on that clutch DONT accelerate and DONT brake either)

 

[jribeiro]

where is this sensor located? the code for the g202 clears but the g200 code doesnt clear so shouldnt that be the fault?

 

[hades-]

whats the codes ?

 

[jribeiro]

wheel angle sensor g202 and sensor for lateral acc g200

 

[hades-]

you already posted that
i asked for the codes ?

 

[jribeiro]

i got 01542 and 01423. not sure if these are the codes that you asked for. i used a autodiagnos machine my mate has

 

[jribeiro]

i have also noticed that if i press the esp button on my centre console nothing comes up on my dash as it should and also if it helps or makes a difference my steering wheel is completely out so if i straghten the steering wheel my car goes to the left.

 

[Sevv]

well it depends i was unlucky and my lateral and longitude sensor were 2 in 1 (AMK engine 2001) located i think near the steering column , you will also need to reset the vaules on a FLAT surface iirc to 0 on VCDS... however on the other hand if your luck i think 1 of them is behind your glove box and the other is around the steering column and that would come to a cheaper affair. not 400 pounds from the stealers

 

[jribeiro]

could the steering wheel being completely out have anything to do with it? Also like I said before when I switch ignition on no eps light comes on and if I press the button nothing happens?

 

[<tuffty/>]

could the steering wheel being completely out have anything to do with it? Also like I said before when I switch ignition on no eps light comes on and if I press the button nothing happens?

....and there it is....! so what you are saying is that when you are driving straight the steering wheel is not straight?... if this is the case then yes... this could most likely be the issue as the ESP system relies on several sensors one of which is steering angle...

Quite an important bit of info that

<tuffty/>

 

[Sevv]

as Tuffty said

 

[jribeiro]

Ok can I adjust the steering and will it be ok? Still need investigate as to why the ESP doesn't come on on the dash when I turn ignition on or press the button

 

[jribeiro]

hi folks
i have checked the car today and there is a connection to the esp button and the fuse is ok but the light does not come on on the speedo when you turn ignition on or when you press the button....
any ideas???

 

[<tuffty/>]

Ok can I adjust the steering and will it be ok? Still need investigate as to why the ESP doesn't come on on the dash when I turn ignition on or press the button

Wheel alignment will sort that issue out... the column isn't splined so no fine adjustment available... only way to do it is laser alignment..

hi folks
i have checked the car today and there is a connection to the esp button and the fuse is ok but the light does not come on on the speedo when you turn ignition on or when you press the button....
any ideas???

Just checked your fault codes (sorry, didn't notice them before...)

01423 - Lateral Acceleration Sensor (G200): No or Incorrect Basic Setting / Adaptation
01423 - Ross-Tech Wiki

01542 - Yaw Rate Sensor (G202): Electrical Fault in Circuit
01542 - Ross-Tech Wiki

Get the tracking sorted so that the steering wheel is pointing the right way first... clear the codes and see what comes back...

I'll say it again... get the wheel straight 'first'!!

<tuffty/>

 

[jribeiro]

Thanks mate appreciate your help. Will look into doing that ASAP. Will let you know of the outcome. With the ESP not coming on on the speedo with ignition turning on what could it be?

 

[<tuffty/>]

Thanks mate appreciate your help. Will look into doing that ASAP. Will let you know of the outcome. With the ESP not coming on on the speedo with ignition turning on what could it be?

As said mate... its all interlinked... the steering position sensor will be out of calibration due to the steering wheel being off centre.. thats tied to the ESP system and the ABS system... fix the steering wheel problem, clear the codes and drive it a while so the system can recalibrate itself then see if the fault persists... it takes a little while for the system to recalibrate itself and you may well find it will all start working again...

If you still have problems then rescan for fault codes and we can go from there but its pointless suggesting anything until you know you have the system configured as it should be

<tuffty/>

 

[jribeiro]

Ok thanks. Reason I ask about the ESP is because even when I press the button nothing appears on the dash? Is it normal for it not to work if the wheel is not straight? Or could it be a separate fault.