2003 Envoy - CEL - Cannot Read Codes - HELP PLEASE !!!!
PLEASE READ THROUGH THIS CAREFULLY - I believe I have explained it well.
2003 Envoy .....
Check Engine list came on.
Connected Code Reader and NOTHING
Connected Code Reader to another vehicle to verify it works and code reader works fine.
Vehicle starts and runs fine.
WHAT HAPPENS WHEN CODE READER IS CONNECTED????????
#1 Nothing on the code read AT ALL. When I turn on the code reader and power it on with internal battery and go to run diagnostics it tells me " must be connected to vehicle "
ON THE DASH -
With code reader disconnected everything comes up and looks fine. Start the vehicle and the lights come on and go off as expected ( expect " Service Engine Soon "
With the code reader connected the following lights come on after starting ....
Clearly connecting the reader to the port has some effect.
Believing I am looking at an electrical problem and not wanting to run it to a shop just yet ........
What am I looking at ?????
Where do I start ?????
NOTE: Battery was recently replaced as old one had a physical failure - unable to tighten ground cable.
ALL HELP IS APPRECIATED ----- THANKS