# PO 505: Idle Control System Malfunction.



## shibapj (Dec 3, 2003)

Folks,

My Sentra GXE (96 make) threw up a 'Check Engine' dashboard warning symbol suddenly. The diagnostic says 'PO 505: Idle Control System Malfunction'. One kind soul told me it is the 'Idle Air Control Valve' which needs to be repaired/ replaced. Any idea/ suggestions? Would appreciate your help.

Thanks.


----------



## dfalcon02 (Apr 9, 2003)

the exact same thing happened to me. you will probably have to replace the valve. it shouldnt cost more than $200 dollars. im sure the valve has gone bad, as this has happened with many people with 1995-1998 sentras, particularly the ones built in mexico. most nissan dealers should have the part.


----------



## sfhellwig (Feb 4, 2003)

The same problem has come up on alot of cars but I haven't seen alot of people replace them. Try cleaning with TB cleaaner first, then replace. Awfully expensive part to find out that wasn't it.


----------



## shibapj (Dec 3, 2003)

Thanks for your replies. It was quite an eye-opener. What is the TB Cleaner and how do I clean the valve with this? I fully agree the valve cld be too expensive.. Wld the engine or any system get damaged for a faulty valve?


----------



## sfhellwig (Feb 4, 2003)

The engine wouldn't be damaged by this particular valve, it would just cause the car to run poorly. It usually shows up as a lumpy idle. Odd that it throws a code and the car isn't running funny. TB stands for Throttle Body and you can get the cleaner at most auto stores. I just removed the valve, sprayed it with the cleaner, and wiped it down with Q-tips very gently. This turned out to not be my problem so I don't know what a malfunctioning valve would act like.


----------

