Hello I recently acquired a 2010 Chevy Silverado 2500HD

When I got the truck it had the steering column apart with the ignition switch hanging out.
It will not start but the lights will come on. When I first tried to start it, I thought I might have had a non-transponder key as it wouldn't even try to turn over. Tested the starter and jumped the relay and it all works but I can not get the engine to turn over.
When I got a new transponder key cut but not programmed, it doesn't see it as a bad key. The passlock light comes on with the initial light test across the dash then goes out. As I have never worked with a passlock system before I am at a loss to what could be causing this.

Any advice on where to search or what to test next would be greatly appreciated. I am thinking it might be the passlock sensor or the ignition switch might be bad.

 

If the passlock light doesn’t flash when attempting to start the truck, it’s not likely to be a key issue. Check to see if the light occasionally flashes with the key off and the doors locked - I’d have to verify but I think it should flash about once per minute after initial key off. If it does, this indicates the security system is functional.

If the ignition switch and key cylinder were separated when you bought the truck, it’s possible they weren’t correctly aligned when reassembled.

The ignition switch and key cylinder both need to be in the ON/RUN position for correct installation.

Beyond that, the key and switch are just inputs to the BCM which then communicates with the PCM that engine start is being requested and that the correct key is present.

If the PCM isn’t receiving the start request or there is a key related problem, the PCM should store corresponding codes, even if the CEL isn’t lit.

Security codes are P16xx.

If there’s a loss of communication, codes will be U10xx.

The last 2 digits will be specific to the problem.

If the code reader doesn’t power up, check the underhood fuses for the cigarette/cigar lighter (also sometimes labeled accessory power).

 

I am not getting any trouble codes from that.

Should I not get any form of fault or notification when an unprogrammed key is attempting to start the vehicle?


Update. Problem solved. Since I never had it started since I bought it I played with the ignition switch and it was simply out of place of the lock cylinder. The one thing I hadn't checked before.