My engine idles around 600 rpm. It has been like this from the factory since day 1. Yesterday, I noticed that my idle speed was around 900-1000 rpm. It did go back down to normal only twice yesterday but otherwise stayed high. It was a warm day here yesterday and so I don't think a prolonged engine warmup was the case. I don't have any engine mods. It is completely stock. All maintenace is up to date as well. I currently have 33k miles on it. Any ideas what is causing this?

 

did you have the a/c on? the ECU will bump up the idle when the compressor is on

 

I forgot to mention that I did not have the A/C on. I am aware that this does kick up the idle speed. I drove it all day today and still it was high. Looks like I will have to take it in. Great!