Okay so hopefully someone can figure this out I've done research and can't find a solution or anyone else that has had this problem. Sometimes all the door controls do not work on my driver side door in my 1999 c5 and sometimes they do, my tuner has told me for some reason my car isn't able to accept any tunes unless the driver door is closed. Also my key fob has stopped working and I've tried reprogramming it with no luck but it does accept the fob and the fob is connected to the car after programming but won't lock or unlock the power locks?

 

 

https://itstillruns.com/program-c5-c...b-6934869.html

 

Check the wiring harness that goes between the body and door. There are known issues with the contacts in the connectors in this area, bent or corroded pins etc. There can even be a damaged wire, insulation compromised.
Gary

 

I agree. The first thing I would do is use the DIC to see what codes have been set on the car. The car's On Board Diagnostic system can read all of the codes while OBD II scanners are limited to codes generated by the power train. They can't see the other 45% of the codes that can be generated by the car. Codes don't necessarily tell you what to fix but they do tell you where to start looking for a problem. Once you get them you could post the list in this forum to see if you can get added help.

After that the next thing I would do is check the wiring inside the bellows that goes between the body of the car and the door. There is a long history on the C5 of those wires being damaged over time. The combination of codes you see may point to the wiring as an area to look at.

The key fob communicates with the Remote Control Door Lock Receiver which then communicates with the door control module trough the serial data link that connects all of the modules on the car. The RCDLM is located on the LH side of the rear compartment, behind the side trim panel. A branch of the data link goes through the door bellows and if it is shorting out to either a ground or voltage that would explain why the tuner is having issues tuning the ECM since the ECM is connected to the data link. If the connection was just open the ECM wouldn't be affected. I suspect you will see codes related to door voltages and the data link when you check the codes.

Bill