There are a few possibilities.

One is that this is not the programming sequence for this truck but I have verified your wiring diagram, your pins are correct and #8 is the key programming pin and most GM jumpers to activate things are to ground.

Up next is the DLC ground. Pins 4 and 5 are joined together to the same frame ground point. Check the resistance from 4 to battery negative.

Up next is the blk/wht wire from #8 on the DLC to the remote keyless entry module near the lower left side of the I/P. If you can get to that wire and connector you can check the wire continuity or back probe and ground that pin at the module. It's C1 H, but I bet its the only wire of that color code at that module

Then it would be that module

Then its everything that talks to and its wiring such as the BCM.


George

 

Scratch that last comment, the Remote Keyless Entry Module controls all the door locks directly.


George

 

I probably won't be able to test this until the weekend but I will definitely check out the resistance for pin #4. If I get any updates I will post them when I can. Thanks so much for your help!

 

As the years marched on the programming sequence changed and moved to opening doors, turning ignition keys and pressing buttons. It might also be worth a try to test these in case you got the newer system in your truck or both methods can work in a transition year.

 

I remember reading about those too so I'll give those a try just in case. I can't remember if the key fob changed for those years or stayed the same square design and hardware?

 

Some examples:

Hold down unlock on the door.
Cycle key on, off, on, off. Doors should lock and unlock.
Hold down unlock and lock on key fob until locks cycle again.

Programming keyfob for my 99 s10 blazer is pretty straight forward. All I have done is open passenger door. Then press and hold both lock and unlock on keyfob for about 7 - 10 seconds. Vehicle will lock then unlock. Repeat with additional keyfobs.

There may be more,

George

 

Thanks again I'll update when I get a chance to try it out!

 

One more for now, my 2002:




George