Diagnostic Trouble codes

In response to a private request -

http://www.autotap.com/codes.asp

Generic DTCs list -
http://www.autotap.com/generic_trouble_codes.html

Enhanced data parameters (not available on inexpensive scanners)
http://www.autotap.com/enhanced_parameters_gm.asp

Some tools (the professional one I borrowed for example) allow a
troubleshooting mode that reads the actual sensor values (in addition to
reading the trouble codes).

Hope this helps,
Oppie

 

Should have also added this link explaining the codes.
http://www.flatratetech.com/pub34.htm