2009 Toyota Camry - AC causes rough idle

when first turning on ac it idles rough for about 5seconds. Only notice it when car is in park. Never stalls out.

If the belt that drives the compressor is loose, it can vibrate a lot when first under load. There may also be a problem with the compressor or its clutch that means there’s too much resistance to turning when it first starts.

The engine is supposed to compensate for the additional load of the AC compressor but it sounds like yours isn’t. Try cleaning the throttle body and see if that helps. A faulty idle air control valve could also be responsible.


For years (like 30) i drove my Toyota Celica without the idle-up vacuum switching valve (speeds up engine with A/C on).
At the time, I ordered my car with A/C. When it arrived at the dealer to pick it up, they were installing the A/C unit in the parking lot. Car came off the boat from Japan sans A/C.
The A/C came in a kit, from Toyota. The techs simply forgot or neglected to install the vacuum valve. When I got into maintaining cars, I had looked for the valve, but no longer made. I took a chance and got one from a 1984 Tacoma. Even the electrical connector fit. Engine speeds up with A/C on now.

There was also supposed to be an “undertray” as Toyota calls it, below the glove compartment. Missing.

This car is newer than that . . . it has an electronic throttle body

It appears to have both an idle air control valve and a throttle body: https://www.toyotanation.com/threads/cleaning-2009-camry-gen-6-throttle-body-and-iac-valve.1186649/

A 2009 Camry doesn’t have an idle air control valve

If you want to prove me wrong, post a picture of an idle air control valve for a 2009 Camry

I’ll give you a gold star for the day if you do so :smiley:

I read a little bit of that discussion in the link . . . and those guys also state a 2009 Camry has an electronic throttle body without an iac

Well, rats. I can post a picture of an idle control valve for a 2005. Does that count? :smile: I know a faulty IAC valve can cause the problems the OP is having and when I saw the ToyotaNation reference to cleaning it I figured the car had one. I mean, why clean it otherwise? Thanks on behalf of the OP for setting us both straight.

1 Like