When I bought my 00 trans am I had the SES light on, car runs fine other than my feeling that it runs rich, may be o2 sensors (I get about 250miles to a tank). Only mod is a magnaflow cat back. Anyway, I decided to get the PCM read and upon plug in the machine just shuts off, will not read. I checked all fuses and not one is blown. I'm pretty stumped on this one, any input will be appreciated.

 

Is the OBDII port powering up whatever you're plugging into it?

 

The OBDII just powers down won't read at all...they plug it in, it powers on for a second then powers off, did it to 2 already.