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View Full Version : Sporadic Hazzard lights !!! Help



welshdave
09-04-2009, 09:09 PM
:mad: Can anyone help ? I have a 2002 tt 225 coupe, over last few months have had a number of niggly problems but the one that doesn't seem to go away is the random flashing of the hazzards - with no alarm sound?

one company maintained it was the convenience unit and replaced this - only to find the problem came back - recently been into Audi who maintained it was the alarm siren and a defunct back up battery - replaced with new - problem came back, more recently i have now replaced the Hazzard dash swithc and relay - thnking after getting some advice that this would kill it ! oh no ! after seven precious care free dravng days - the problem is back !! i am now at the end of my tether as Audi have said they can put it on a diagnostic programme but not sure this will find the fault? any help or advice would be very welcome as i am sick of spending out !!

a8 tech
09-04-2009, 09:15 PM
ok first start to bypass the bonnet switch and the ultrasonics then also there can sometimes be a crash signal sent from the airbag control unit which triggers the hazards so check the airbag control unit connection and any faults relating to crash signal in central locking or airbag.Post a fault code log for further help

welshdave
09-04-2009, 09:26 PM
Hi A8 Tech, thanks - funnily enough it was put on a diagnostics by Audi when they replaced the Alarm siren and it came up with a sporadic crash signal? - this is also what the previous company also reported and had suggested to replace the air bag control unit after they established it wasn't the convenience unit - is this necessary given it hasn't had any impact? dont have a fault code as results not given to me by Audi !

a8 tech
09-04-2009, 09:34 PM
Great,ok condensation builds up on the Airbag mulitplug which causes corrosion of the terminals which then creates a resistive circuit and sends the crash signal so you need to inspect the connection and depin (remove the crash signal wire) to the hazard switch to confirm this is the cause,simples

welshdave
09-04-2009, 09:41 PM
Sounds promising - but haven't got a clue how to locate the areas you mention or what to do ? can you be any more specific? give me some direction here - i.e. where to find the airbag multi plug or the crash signal wire to the hazzard switch ? any clues ? sorry for sounding vacant ? is this something i can do myself ?

a8 tech
09-04-2009, 09:48 PM
Its hidden under the center console so i would suggest the dealer or local indi,i would post the correct wire to remove but i no longer have the info on this lap top.The easiest way would be to remove the hazard switch and remove the crash signal wire there first but i can't tell you the wire at this time.

welshdave
09-04-2009, 09:53 PM
Cool, thanks for this advice, I will seek out somewhere open perhaps tomorrow or Satruday but gven its Easter don't hold out much hope ! but your advice is great - if you get information on the crash signal wire that would be great

Have a good Easter ! fingers crossed ! ;)

a8 tech
09-04-2009, 10:00 PM
im off work for a week so i cant get to my Elsa.
Happy easter to you to,im going fishing and no cars to fix for 10 days,love it

welshdave
09-04-2009, 10:03 PM
Enjoy! will let you know if get it sorted , but am now alot more hopeful - thanks again -

welshdave
17-04-2009, 10:22 PM
Hi A8 Tech - picked my TT up earlier from the dealer and guess what !!

following an arduous process of diagnostics they finally got round to checking the multi plug as you had suggested - basically no signs of corrosion or condensation but the clip that secures it in place was broken (presumably by the independent who looked at the ar bag control unit in Feb- and who wanted to replace it !!) audi resured the multi plug and using their wisdom rather than charging me for a new plug and labour - secured it with electical tape - this then resulted in all the faults being removed and some switches which i hadn't realised were playing up - i.e. the internal sensor switch in console worked again- following further diagnositics all faults disappeared!!! although am a little peeved at being £150 out of pocket - your advice at this time - crossing all fingers and toes saved me possibly a further cost of several hundred pounds - and no new air bag control unit required !!! whoopee and i can't thank you enough - although still cant believe they didn't thnk of this themselves - hey ho they not as ingenius as you - thanks again - ps hope you had a great holiday ! :biglaugh:;)

a8 tech
17-04-2009, 10:26 PM
no problem and i have had a great week of with my son and a bit of fishing

welshdave
24-04-2009, 08:02 AM
:aargh4: Disappointingly - within 12 hours the problems returned and since has happened quite a few times. In fact a few days ago they started going off when i was actually driving! its back with audi ! I have told them that don't intend to pay for duplicated labour and also that my expectation is that they will resolve this problems once and for all !

Thewy were receptive to the advice that you gave me which I passed on and I almost got a sense of embarrassment that a customer had had the inclination to seek advice from a third party?

I guess will have to wait and see but one other thing that has happened is the interior sensor swithc for the alarm in the centre console stopped lighting up as well and ironically when they reftted the multiplug it started working again - since the problem has come back its not working again. any ideas would this be connected ?

a8 tech
24-04-2009, 08:37 PM
Strange,the airbag crash signal can be easily bypassed to confirm its involvement but your fault looks like possible central locking control unit issue also.Again can't help any further with out a diagnostic log.I would say both issues are linked.Regards A8

welshdave
27-04-2009, 01:21 PM
Thanks, its been with Audi all weekend so I am awaiting to hear if they have figured out the problem yet.

Will come back to you -apologies but been away for weekend.