How to replace idle air control valve?

TONYLSF

MEMBER
2017 TOYOTA HIGHLANDER
3.5L
V6
2WD
AUTOMATIC
96,000 MILES

Car isn't turning on, when car was on the idle when high passed 1. Battery is brand new. After checking code, I got error code P0505 idle control system P0174 system too lean bank 2 cleaned with carburetor with throttle cleaner and cleaned master flow with master flow cleaner. Problem temporarily fixed, but issued retuned next day.

1 Reply

KEN L

MASTER CERTIFIED MECHANIC
48,363 POSTS

There is no idle air control valve on this truck. There is a problem with the truck holding the idle speed, this is why you get this code and with the lean code it sounds like you have a vacuum leak.

Code P0505: Idle Control System Malfunction

Code P0174: System Too Lean (Bank 2)

Here is a guide to help you find the leak, use it when the engine is cold only:

https://www.2carpros.com/articles/how-to-use-an-engine-vacuum-gauge

Here is the lean mixture guide to help understand that problem as well:

https://www.2carpros.com/articles/repair-lean-mixture-codes-p0171-or-p0174-on-some-manufacturers

Please go over these guides and get back to us.