mk1 leon immobiliser issues

[pugparcels]

hi guys, rare i need to post on here as there is so much info available. but this is stumping me now, our mk1 leon cupra 74000 miles has never really let us down but yesterday the wife called to advise me the car would not start and the car with the little key in it logo on the dash was flashing.

i came home about an hour later to try it and it all worked. the wife went to go out this morning and again the immobiliser light on the dash flashed after the key was put in again turn the engine over, within two seconds the immobiliser had shut the engine off.

i have a hand held tool that lets me read the error codes and i am getting 17978, which seems to relate to according to the site 'control module locked' is this part of the immobiliser issues that i have seen involving the dash being removed and soldered or is this something else?

i am a bit more stumped now as i disconnected the battery earlier and connected the positive and negative terminals together as i read for 30 seconds but did not seem to make a difference. i have now been back out tried the car again, started first time with no warning light. tried it a good few times and then the light started flashing, but i still tried to turn here over and she fired and ran?

im now really stumped, where should i start looking? any help would be really helpful.

cheers
chris

 

[mty12345]

hi mate, full info on that code here http://wiki.ross-tech.com/wiki/index.php/17978/P1570/005488
As mentioned in that document the immobiliser fault codes are stored as part of the instruments module not the engine module. Not sure if your code reader can read instrument faults? if not you might need to get it on vagcom

 

[pugparcels]

thanks for that, with out sounding too daft what does it mean in english? is that relating back to the dash being suspect? or something. if it likely to be the dash i would rather whip it out myself rather take it to a dealer.

i cant see it being the keys as they didnt work yesterday evening but then worked late last night. i leaning more towards either something in barrel area or the dash. im going to strip of the cowl around the wheel this morning check for anything loose / broke and then if no joy there move on to the dash to have a look at the green plug connection there etc.

 

[pugparcels]

ok i have had the clocks out and all looks good there, the solder on all connections look really good. the pick up / reader coil looks ok, but i have checked all connections on the pick up and clocks and cleaned them up with contact cleaner. re-connected the battery and tried her again, all worked fine, no signs of the immobiliser light on the dash.

if this is an intermitant fault does this lead more back to the pick coil rather than the clocks?

cheers again

 

[pugparcels]

right just been down the local vw / seat / audi specialist ( not main dealer ) and after explaining the issues, as the car has now decided it does not want to work again. he believes it maybe cold be the pick up coil on the barrel.

he has also said the new coil will need coding to the car, is this right? as i was told this morning by another garage it will not need coding.

 

[mty12345]

Hi buddy, yh i'm 99% sure it will need coding to match your key if a new coil is fitted. What i meant about the instruments, is that when you look for fault codes with vagcom/vcds/ another fault scanner etc. I'm pretty sure that any immobiliser faults are stored on the "instruments" control module, as opposed to the engine module or abs module for example. Anyway with the fault being intermittent it does sound likely that the coil or the wiring to it is the issue, having a new one fitted is probably your best bet i would have thought

 

[pugparcels]

thanks fella, how easy to get the part number for the coil? couldnt see anything on the existing one except for a small number '50 00f' i think it read.

didnt look like a vag part number to me

 

[Muttley]

As far as I know the only items that need "adaption" i.e. recoding if replaced are the ECU, the immobiliser control unit (part of the dash panel circuit board) and the keys. I don't see how the reading coil could require coding, it's a passive component, literally just a wire coil.

Are your problems confined to just one key, the one your wife uses?

 

[pugparcels]

its happening to both keys, there is no pattern to how often it is happening to one key. think i might try known working coil from a breaker , will be cheap test rather then taking it straight to the garage. see how that goes

 

[pugparcels]

ok been a long time since i posted to this thread but now things are getting interesting. after the car went into the garage i was quoted about £1100 for the parts, labour and coding.

the parts consisted of a new set of clocks, reader coil, barrell & keys. after a couple of days waiting to hear from my garage who were waiting on seat they advised me the clocks for our car are obsolete and they could not get any.

they then suggested trying things a different way....the short version was to tell the ecu there is no imobilisor on the car meaning all original parts could stay and the bill would be pence in comparision. along with this they would map her for me at the same time. ( 180 up to 225 approx )

this was successful for about 2 days, then the same fault occured, they now believe the ecu could be at fault or was possible at fault from the start. now none of this is costing me anymore money so i dont mind them trying what ever needs to be done to resolve the problem.

HOWEVER...they have now been able to get an ecu for our mk1 cupra, they have advised me they have a cupra r ecu, which i understand starts life at 225bhp and can be mapped to around 250bhp?

my concern is can the standard part of my mk1 cope with the cupra r ecu, if so, can it then cope with a mapp of around 250bhp?

the car is totally standard except for a k&n panel filter. any thoughts would really be appreciated, they are vag group specialists but just a little concerned if a different ecu could cause more issues.

 

[pugparcels]

to update the info a bit more from yesterday the ecu is a 210bhp version not the 225. which has made me feel a little better as from all of the threads i have seen, the 225 ecu is not at all compatible.

however not anywhere have i seen any discussions about a 210 ecu being fitted to a 180. does anyone know if this has been tried before?

 

[Muttley]

Both 210 and 225 BHp engines have a number of differences to the 180 BHp engine. I would have said that neither was compatible. The sensor fit is different.

 

[LEE69]

No get a 180 ecu (i have one here ) the later ones are different

 

[ozaudio]

i had this problem, i took £100 and my ecu to here

http://www.vagtronics.co.uk/

10 minutes later i was on my way home with a car that would now work

 

[pugparcels]

thanks for the reply guys, as the garage was ready to go with this and i'd had no reply by this point ( no offence implied ) i decided to let them try it to see whether it works.

so the faulty ecu was removed ( 180 bhp ) and all information cloned on to the new ecu ( 210 bhp ) the old was installed back on the car and it still would not start, the cloned ecu was installed and it worked first time.

they were then swapped a couple of times back again and the same happened again old would not work, new did.

so now the car was startig and running, because we were still unsure if the clocks / imobilisor were faulty / failing we continued to have the imobilisor 'removed' from the car by 'telling' it there was no imobilisor.

to test this had been correctly, they proceeded to remove the clocks from the dash and the chips out of the keys, so there was just a hole in front of the steering wheel and nothing in the keys for the reader coil to pick up ...they then started the car and drove it from our home to the garage with no clocks in place.

this to me, proves the car believes there is no imobilisor attached to the car. we have been using the car for three days now with no starting issues what so ever.

the gear ratio's do seem different and 3rd / 4th seem to have more pull in them than before so the car is going back in about a week or so to be setup / mapped properly with the new ecu.

but so far all looks promising, whether it makes a difference i call our car a mk1 it is a Y reg but very late Y as in 3 weeks before the 51 plate came in, is this still a mk1 or would it be classed as a later model? would that make a difference to the above working?