OK, working on a new project. Here is my problem: 1995 3.4L automatic recently the idle has been running around 1200-1300 rpms. Pulled the IAC cleaned it off, checked it with the meter. Manual says terminal A to B and C to D should read 40-80 ohms. Both readings are exactly 40. After the car idles for a few minutes, rpm increases to 1500 and SES light comes on. Go to hook up my OBDII code reader and get an error message. I am sure the reader works fine, but this is the first time I have used it on this car. I am getting power to the unit, but it will not read the cars PCM. So, I need help determining if there is something else causing my idle increase and why I can't read codes.