Well I have been having problems with my truck for the past year and no shop has been able to identify the source. Yesterday it went into a shop to have the ECM flashed and this did not correct the problems. I was told that I need a new ECM. Where is the ECM located in a 2009 Colorado? I have found them for sale on-line, but where on the truck is it located. Thank you for taking the time to answer my question. Hopefully a new ECM will correct my problems.