Hello, new owner to the Vette world and I am having big issues with mine. Started after I bought it 6 months ago, it has an ABS light on so the traction control is not working as well. I drove it like this for a while. Shortly after this I would get a reduce engine power warning and the car would not allow me to go pass a certain speed limit. This would come and go from time to time. About a month after all this the gauges and dash acted as if it had lost power, acting crazy. So living in the north east I put the car in storage for the winter and parked it. the weather has been awesome lately so I tried to Start it up. The battery was trash and I replaced it with a new one. Now the car will not start but will crank. the gauges will sweep with the key on and then go away then sweep again. gauges act crazy. when the gauges come on it says reduce engine power on the messages. Can not read any codes because all the modules say NO COMM, the ECM, BCM every single one. So I can not get any codes at all. I did learn that my Dad had attempted to jump start it on the old battery. I know this is a bad idea but he was trying to help when I wasn't around. also when the key is on the start replay under the hood in fuse box will buzz. I have swapped it with another one and same problem. I am fairly mechanically inclined. however being so new to this cars and don't really know where to start. any help would be much appreciated before I send it to a shop thanks.

 

Ignition starter switch might be a good place to start looking.

 

Your car has problems with it's serial highway, on the C5 all the various modules are connected by a wire that links all the modules together, your car has a bad module or wiring problem that is causing the no comms message. I am sure somebody will post on how to troubleshoot this issue, if not do a search on C5 serial highway, hope this helps, and good luck.

 

You may have problem with your serial databus wire connecting all the modules .
Your first step can be to verify if your problems is caused by the serial line to your door and seat modules .
On the left side of the body control module in passenger footwell there is two starconnectors .
Disconnect the connector of the star connector with FOUR wires and try to start the car and see if it make any difference .
(This will isolate the two doormodules and seat module from the serial databus line )

 

YES !!...all “no comms” most likely point to a serial data bus issue !!...I’ve put into some previous threads how to tackle this issue with just a volt meter...don’t have time right now explain everything in detail...search this Forum for “serial data bus” !!