Hi, 2003 Covertible , BOSE getting ripped out and hard wiring a whole new stereo system in. The chimes run through the stereo system from what can see in the wiring schematics. Attached. When tracing everything out, all the signals look like they rudn through data lines. On the radio schematic there is a DK GRN #15 (E&C Data) and a ORG #16 (Serial Data) wires. Does anyone know if either of these is just a chime signal sound wire? I was hoping they run the tone through one of these so I could run it to my amp to keep the chimes. You would think it would be that simple but knowing GM and not wanting to toast my amp or the vehicles data system, GM probably made some type of overly complicated circuit board in the radio to make the chime sounds when it sees the data signal. Any help is greatly appreciated.

 

There was a thread on the door/key chime a year or 2 ago. It caught my attention because mine stopped working a while ago. I think the conclusion from that thread was that the sound comes from a small speaker like part of the instrument cluster.

 

I confess that I haven't looked into how the chime works. But, the likelihood that there is a "chime wire" is exceedingly slim. The C5 has a multiplexed architecture. What does this mean? It means that instead of individual wires for every conceivable signal, there is instead a communications bus, much like the Ethernet computer network that links the PCs in your home, work, or school. All of the control units that need to exchange data can communicate and exchange data over this bus. For example, the instrument cluster needs to know the road speed, but there is no "road speed signal wire" from the ABS ECU to the instrument cluster. Instead, the ABS ECU broadcasts the road speed data over the communication bus and the instrument cluster monitors the bus and drives the speedometer display accordingly. Similarly, the radio also monitors the road speed data from the ABS ECU, so that it can automatically increase the volume, in order to compensate for road noise at high speeds.

Without performing any research, my first impression would be that the logic for when the chime needs to be enabled is probably located in the body control module and when the specified conditions are met, the body control module likely sends a message to the instrument cluster requesting it to enable the chime. Once again, this is only a guess. There may be some clues in the workshop manual, or the electrical diagram, but as a rule, this sort of data is not generally provided to the dealer techs, unless they have a specific problem and they contact the manufacturer about it, directly.

Per ​​​​@bookyoh 's suggestion, you might search through the archives of this site to see if anyone has turned up any specifics on the chime function.

 

Bookyoh is correct. It comes from a small speaker on the back of the IPC

 

Yes all chimes are played through the IPC. None go through the factory radio for the C5.

For the C6, the chimes go through the factory sound system.

Gary

 

Removing the stock radio has absolutely no effect on the chime system. You will get a no com message on the IPC when you scan the codes from the DIC.

 

Appreciate the information. Thanks to all who chimmed it! LOL had to use the pun...