fault code 17705 mk4 golf gti petrol aum

[gticraig]

has anyone any idea what this fault is or how to cure it ? i have a golf 02 plate gti petrol,the car has this code stored n basically doesnt tick over very well if at all,read various posts on various forums but not getting no proper answers apart from people just replacing everything then calling that a diagnosis if it works.any help much appriciated

[chris.fulton]

The code indicates a pressure drop between the turbo and throttle valve. Never had this problem myself but I would start with looking for a boost or vacuum leak. Check all the turbo and vacuum hoses for any splits or if they are loose and listen out for a louder than normal whistling noise under the bonnet, this would indicate a boost leak.

Other possible suggestions would be a faulty bypass/diverter valve or carbon buildup in the throttle contol module, around throttle blade (which is not uncommon apparently)