Likely PASSLOCK issue
Visiting my mom, her 2008 Chevy Colorado 4x4, I5, auto is having intermittent no crank, no start issues with the "security" light flashing. I believe this indicates a problem with the truck's Passlock system. This is the version that apparently has the security mechanism inside the ignition switch, not the little resistor in the key like the older PASSKEY/VATS systems.
I have bypassed the older VATS before by splicing in a resistor equivalent to the one on the key but that method does not appear to be viable for this PASSLOCK system. I did find some information about people claiming to bypass one version of PASSLOCK by measuring the resistance in the cylinder but those threads referred to wire bundles and colors (3-wire bundle from sensor with red/wh, black, and yellow, like I saw with the older VATS) that are not available in our truck, so I don't think the technique applies. I also saw some posts about cutting the blue/white wire but I am not willing to go that way.
So I am thinking that the only alternative is to replace the ignition switch and do a security relearn.
Anyway, since it took several days for the mod to get my account here activated I have made some progress. I removed the ignition switch last evening and will pick up a new one today at the local Chevy dealer and post back the results.
Last edited by raylo32; 07-14-2016 at 07:40 AM.