Car stops boosting at 2500 rpm. Have codes!

[Dan_Cupra]

hi iv had my cupra for 24 hours ! it stops boosting at 2500 rpm (never did it b4) you hear it spool up and hits 2500 and stop and jus sluggish as hell. checked for boost leak, intercooler normal little checks you can do.

its completely standard 36,000 miles fsh.

had it on snap on diagnostics and its came up with following codes;

17794 ECU Defect
17733 Knock control cylinder 1 and also 3, 4 and 2 on different codes
18010 power supply terminal 30 low
17963 p1555 max boost exceeded

any help be muchly appreciated Dan.

 

[DPJ]

Faulty N75, I would say.

17794 code is strange........

 

[cus]

18010 power supply terminal 30 low

think that code means that the battery has been disconnected recently.. someone will correct me if i'mwrong though!

could be the n75 valve, as its overboosting. make sure that valve is clamped down nice and tight. that was my problem.

 

[cus]

oh, and check to make sure no water has got on the ECU. its underthe scuttle panel, on the driver side.

 

[Dan_Cupra]

cheers ppl, wheres the n75?

 

[DPJ]

The N75 is on your Turbo inlet pipe. It has an electrical connector and two vac pipes running from it.

 

[cus]

its the valve near the MAF sensor which is just after the air box. you'll see 3 pipes going into it, and a cable as well.

sits on the side of the turbo intake pipe (TIP)

 

[Dan_Cupra]

ill go try it now =)

 

[cus]

DPJ - its three, one to the intercooler pipe, turbo and TIP hasn't it?

 

[Dan_Cupra]

actually ill wait till morning lol but thanks for the help il let you know if it works.. should i worry about any of the other codes?

 

[DPJ]

DPJ - its three, one to the intercooler pipe, turbo and TIP hasn't it?

How many vac pipes?

 

[cus]

How many vac pipes?

so only has two??

i'm sure it has three..?

 

[Dan_Cupra]

all hoses are attached =( does that mean my N75 valved F**kkkd ?

 

[cus]

it 'could' mean that. are the pipes clamped down? when igot my car, they weren't, and that caused it to overboost. - it could still mean the N75 is faulty though

also, have you checked the ECU for water damage?

 

[Dan_Cupra]

what happened was i tried it in 1st hit about 5000 rpm then boost stopped completely like a major overboost. it now and again boosts and pulls hard still cuttin out tho at high rev , most the time theres nothin at all, unfortunately i havent got a boost guage yet so i cant see if its still boostin but id guess its in limp mode so a low psi which feels like nothing. all hoses to n75 are on n tight by them special clamps. ill check the ecu for water damage in the morning, however wasnt raining when happened. Is the N75 dealer only? i no you can get them off ebay but i dont want to wait around tbh for delivery.

 

[cus]

i think eurocarparts do them. but i'd go to the dealer and just get the standard n75 valve.

18010 power supply terminal 30 low - i'm pretty sure this code is because the battery has been reset, so if you haven't done this, then the owner before has.
possibly because he knew about the codes, and was trying to hide them from you?

 

[DPJ]

so only has two??

i'm sure it has three..?

As I said, it is mounted on the tip - with two small vac lines on it. = 3 connections.

 

[cus]

i get you now.. oops!