Leon Cupra TDI limp mode

[johnbowdengti]

Hi all,

New to the forum but done a lot of searching to try and find the cheapest way to solve my problem with a 2004 Cupra TDI (ARL).

Common problem from what I read but not so simple to resolve:

Limp mode most days but hit and miss as to when it happens.
Used VAGCOM and got faults relating to open / short to ground on both N75 and fuel pump relay as well as the 18080 fault code for the cooling fan.
Have noticed that the coolant temp sensor shows some problem as gauge sometimes drops to 70 and then climbs to 90 again?
Checked the earths at the ECU and plan to try a new N75 and temp sensor but where else should I be looking?

All help very much appreciated

Not getting overboost so reckon VNT is fine?

Cheers

 

[adam cupra 20vt]

Temp problem sounds like thermostat to me but easier to change sensor first.

 

[johnbowdengti]

I believe that VAGCOM suggested intermittent temp sensor so I will replace and see how it goes but its the N75, fuel pump relay and colling fan issues which worry me?
All open or short to ground so could do with a wiring diagram to see if they are a common ground point as wiring around then looks okay?
Bought it like this so not complaining but dont want to replace each part for nothing!!
Cheers for reply mate

 

[adam cupra 20vt]

Does it go from 90 to 70 when you go up and down hills or brake and accelerate hard?

If so I'd say thermostat if not I'd say sensor.

I don't know about the others, have you cleared them to see if they come back? they could have been on there years.

 

[johnbowdengti]

Yeah cleared them and they come back - sometimes instantly, other times they take a while. Coolant temp is really random and not often so less concerned.
I will try replacing main battery ground and N75 unit and see if that has an affect

All good fun.........