intermittent power loss - a right pain!

[Foz550]

Hi, I posted this in the TDI section but have had no repies so I hope people dont mind me putting it in here as well!!!

Am having big issues with my leon FR TDI (55 plate, 52k), it keeps intermittently losing power (feels like the turbo goes) which if I turn the engine on and off again stops the problem and all is well again.

VAG said it was the fuel pump relay, so had that changed & still same issue & I have now had the fuel pump changed as well and I still seem to be losing power intermittently.

When I had the fuel pump changed my mechanic did a lot of VAG tests etc & it came up with the following code/problem:

17957 - Boost Pressure Regulation Valve (N75): Open or Short to Ground

P1549 - 35-10 - - - Intermittent

Anyone got any ideas on what my problem could be? Is it likely to be this N75 valve?

Ive also had the following code come up a few times, do you guys think I need to change the fan system? my mechanic says this wont fix itself and will slowly get worse & pack up, apparently quite common?

18080 - Coolant Fan Control 1: Open or Short to Ground

P1672 - 35-10 - - - Intermittent

Thanks in advance!?
Dave

 

[sssstew]

no response in the TDI section... odd. sorry about that.

Anyway, i would certainly try swapping the N18 EGR control valve and the N75 Boost control valve on the back firewall and see how it goes, this should help you identify if the N75 is faulty, then you can get a new one and swap out, easy part to replace.

 

[johnbowdengti]

Got the same problems with my Leon Cupra TDI - N75 open short to ground as well as the same for the cooling fan and fuel pump relay. tried earth points at ECU and going to swap N75 but think it must be a larger earth problem so thinking of replacing main battery earth strap.
have you had any success or advice?

I will keep you posted

 

[phatchoonz1]

Got the same problems with my Leon Cupra TDI - N75 open short to ground as well as the same for the cooling fan and fuel pump relay. tried earth points at ECU and going to swap N75 but think it must be a larger earth problem so thinking of replacing main battery earth strap.
have you had any success or advice?

I will keep you posted

Any success with a fix for this?

Got exactly the same issue with a cupra tdi myself now.
Got Codes for N75 short
Cooling fan 1
and
Fuel pump relay

 

[supersyz]

I'm having just the same problem with my 1.8t cupra, sometimes i start her up and she has less power and i dont hear the turbo as much or the dump valve, soon as i turn it off and on it fine again. I just noticed today that even when it starts with full power after a cpl of mins it goes to low power again.

Thnx in advance, Sy