Hi Guys,

I started my 05 sti the other day when it didnt seem to be running properly. The revs were surging from 1200-2000rpm.
The engine management light then came on so had it plugged into a diagnostic machine that gave the code P0519 Idle Control System malfunction failsafe.
Can I assume that this is the problem or could it still be something else other than the idle air control valve? Air leak, MAF, etc?
The car is only a few months out of warranty and a new IACV is £375!

Has anyone experienced this before?

Cheers

 

had the same problem with mine turned out to be the idle control valve,i had mine swapped for another and all was fine after that.i have heard that some people get away with taking them off and cleaning them,so might be worth trying that first.

 

i have to clean mine about once a year as it sticks. Take it off(2 screws on top of throttle body) unplug the wiring and soak it in wd40. Its likley the flap inside is gunged up