Dead leon 1.8t help?!

leon_cupra_666

Guest
Hi guys replaced my faulty 02 sensor on saturday cleared the eml light with vag com and drove the car about 30 mile round trip did the trick....... went out in the car today and it was fine then all of a sudden traction control light came on and eml then car just died......now there is no EML light at all when you switch the igntion on and car wont start at all, AA been out say its the Relay 409 (Fuel Pump) but i can no longer communicate with the ECU so could be relay or maybe dead ECU?!

if its the worst case and i need a new ECU how do you code it into the car or are they plug and play?

thanks in advance for you help gutted love the Leon but dont need the agro this time of year :
 

carlossus

Active Member
Nov 13, 2010
153
0
Bournemouth
You didn't clamp through lambda probe wires, shorting them together / to chassis or twist them severely did you? That *will* pop the ECU if you're unlucky - fuse if you're lucky.

The ECU isn't plug n play as it's matched to the immobiliser in the cluster. But, it can be cloned easily (not by Vagcom).

If the ECU is fried, I can help.
 
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leon_cupra_666

Guest
Na defo didn't twist or clamp the 02 sensor's was an easy swap and the car drove spot on after....really hoping its only the relay but strange i can no longer communicate with the ECU via vag-com so maybe the ECU needs replacing.....thanks for your help mate absolutely gutted!!
 

LEE69

Stage 2 Revo'd
Dec 10, 2004
21,262
74
C\UK\Devon\Torquay
You need the skc code vag tacho can pull it from the ecu, but, if your ecu is dead, i'm not sure if it will work.

Fuse 43 is engine control, see if that fuse as blown.
 

carlossus

Active Member
Nov 13, 2010
153
0
Bournemouth
You need the skc code vag tacho can pull it from the ecu, but, if your ecu is dead, i'm not sure if it will work.

Fuse 43 is engine control, see if that fuse as blown.

You also need the SKC of the donor ECU which you can't get unless it's paired with it's immo in the car, which is very unlikely.

We'll all cross our fingers for a naughty fuse.
 

leon_cupra_666

Guest
Mr AA checked all the fuses vut even there kit couldnt communicate with the ECU hope its the relay 409....is there an ECU relay?

other thing is when you put the key in the ignition and turn the key to position 1 the eml light does not come on at all like it used to for few seconds and go off etc

i have vag tacho but im guessing if the ECU is dead i could be knackered....whats the easiest way to sort replacement ecu, speedo and transponder from a doner vehicle?!
 

leon_cupra_666

Guest
cool thanks all for your help will check all the fuses....just to check if it is worse case!!

will ecu, cluster and key transponder from a donor vehicle be all i need to get it running again? rather than trying to code just the donor ecu etc?

cheers all
 

seatcupramad23

kc4even23
Sep 7, 2009
3,239
2
birmingham
That's all unreal same thing happen to last lc , sadly mine turned out to be fried ecu , 3 one now with exactly same symptoms I taught this was rare occurance
 

carlossus

Active Member
Nov 13, 2010
153
0
Bournemouth
....whats the easiest way to sort replacement ecu, speedo and transponder from a doner vehicle?!

Easiest & fastest: Buy a second hand ECU that has the immobiliser deactivated. Then it *is* plug and play, but you obviously have no immo.

Or have your ECU immo identity cloned to a donor ECU by someone. Then it's exactly as it should be.

What year is your LC? I assume it's an AUQ?
 

leon_cupra_666

Guest
yep 2001 AUQ haven't got a clue of anyone local that can clone the ecu for me though, just moved to the bedford area if anyone can recommend anyone that could help locally....if not i guess cluster, ecu and key transponder from a breaking cupra will be my next try!!

what a day just what i needed sob :(
 

carlossus

Active Member
Nov 13, 2010
153
0
Bournemouth
yep 2001 AUQ haven't got a clue of anyone local that can clone the ecu for me though, just moved to the bedford area if anyone can recommend anyone that could help locally....if not i guess cluster, ecu and key transponder from a breaking cupra will be my next try!!

what a day just what i needed sob :(

You have my Email. Shoot me a message if it turns out to be your ECU, I have a spare that I could sort for you if you can't find anyone local.
 

leon_cupra_666

Guest
ok bit of an update, replaced the 409 Relay today didnt change a thing still wont start.

removed the ECU too see if there was any obvious wiring issues but all seemed fine, re-connected everything heard the fuel pump prime but still wont start.

Vag com still wont communicate with the ECU did notice the TCS light flash twice when trying to start, on ABS module vag com comes up with steering wheel position sensor fault but surely this wouldn't stop the car starting have had this one on the leon before and usually goes off after a while?!

running out of ideas any other ideas guys?!

seen other bits on google about MAF and TCS or cam shaft sensor?!
 

leon_cupra_666

Guest
Bloody hope so mate managed to get a replacement ECU, Cluster and key transponder of a VAG specialist on eBay for £130 so should be plug and play (keep your fingers crossed)
 

leon_cupra_666

Guest
Right fitted the replacement ECU, CLUSTER and NEW KEY TRANSPONDER and its still the same.....gutted what else can i do next.....cam position sensor? MAF? im running out of ideas anyone out there got any other ideas cant even get the car to a dealers/garage as it just wont start at all?!?!
 
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