I have a Cadillac sts 2007 the door chime the blinker noise and the seat belt chimes all stopped working along with the two front speakers. I do have Bose sound system. The rest radio works fine.

There is no dinger as the other guy suggests . sound comes from the driver door speaker .
The audible warnings alert the driver of a system concern or a critical vehicle condition. The radio generates the audible warnings through the left front speaker. The radio receives audible warning requests via the class 2 serial data line. If the radio receives multiple audible warning requests, the warning with the highest priority sounds first. On vehicles with an audio amplifier, the amplifier instead of the radio generates the audible warnings and receives audible warnings requests via the class 2 serial data line. Either the radio or the audio amplifier is the chime producer. The following lists the audible warning priority and the pulse rate:
Fast rate chime (150 pulses per min)
Medium rate chime (100 pulses per min)
Slow rate chime (50 pulses per min)
Turn signal reminder (will pulse at turn signal flasher rate)

Your best bet ,wear your seatbelt . so the sound goes off . If you do wear the seat belt and the chime sounds ,have a qualified repair shop check it .

spontaneously alerts ??? Warning chimes Warning Devices The warning device system consists of the following:

• Key-in-ignition warning switch
• Door ajar switch
• Driver and passenger safety belt minder switch (integral to the safety belt buckle)
• Vehicle security module

The instrument cluster and the restraints control module (RCM) control the following chimes:

• Safety belt warning (repetitive chime)
• Key-in-ignition warning (repetitive chime)
• Headlamps on warning (repetitive chime)
• Door ajar warning (single tone)
• Air bag warning (repetitive chime) The following 5 distinct chime rates are used to indicate warning:
  
  • safety belt warning is 1 chime per second
  • key-in-ignition warning is 2 chimes per second
  • headlamps on warning is 4 chimes per second
  • door ajar warning is a single chime
  • air bag warning is 5 chimes per second
  • now which of these is your vehicle doing ?

dealer is correct its a known problem for cobalt can check online their are multi cobalt forums and repair sites about the problem

The chime system is a class 2 databus. The chime is actually created by the factory radio and plays thru the left front speaker. If the radio is non factory and the appropriate kit was not used ( which has a speaker for the chine) or the front left speaker is blown then you won't have a chime. If you do have a factory radio and the speaker plays the music fine then the problem lies in either the data circuit or the radio. If you have an aftermarket radio and the correct wiring kit was used then either there is a bad connection, blown chime speaker or defective kit.

you more than likely have bad radio speakers I have changed many of these on gm vehicles around your model year

it looks like a long relay with a speaker grill on the front of it and its in the fuse box drivers side

Check the radio fuse. As unusual as it seems, GM has started having the radio (even though not turned on) generate the chimes and turn signal sounds. If the radio fails, all the chimes fail too.

This applies to other vehicles besides the HHR. My 2003 Silverado had the door chimes fade down so I could barely hear them. The fix was to replace the radio (under warranty, fortunately...).

Here are the warnings:

The generic electronic module (GEM) controls the following warnings and chimes:

• Driver safety belt not fastened (warning lamp and repetitive chime).
• Key-in-ignition (repetitive chime).
• Headlamp-on warning (repetitive chime).
• Door ajar (warning lamp and single tone).

The following four distinct chime rates are used to indicate warning:

• Seat belt warning chime is one chime per second.
• Key-in-ignition warning is two chimes per second.
• Headlamp-on warning is four chimes per second.
• Door ajar warning is a single chime.

please rate as solved if this is what you needed.

Section 13-09: Gauges, Warning Devices — Chime System 1996 Windstar Workshop Manual
DESCRIPTION AND OPERATION Warning Chime Systems Three distinct sounds are used to indicate the area of concern. Seat belt warning generates 1 chime per second
key-in-ignition generates 2 chimes per second
headlight on generates 4 chimes per second.
Key-In-Ignition Warning The key-in-ignition warning will sound when the driver's front door (20125) is opened with the key in the ignition switch. It will continue to sound until the key is removed, the front door is closed, the ignition switch is turned to START or the vehicle speed is over 24 kmh (15 mph).

Safety Belt Warning When the ignition switch is turned to RUN or START from OFF or ACC, the chime will sound for six seconds or until the safety belt is buckled.

• The safety belt warning indicator lamp (10C859) will activate for 60 seconds or until the driver's safety belt is fastened. Both the chime and lamp activate at the same time.

Anytime the ignition switch is released from START and returns to RUN while the safety belt lamp or chime is activated, the safety belt warning lamp or chime will remain activated until either the timing sequence has been executed, or the safety belt is buckled.

Headlamp Switch On Warning The chime will be activated if the headlamps or parking lamps are ON, the key is not in the ignition and the driver's door is opened. The chime will sound at a rate of four per second.

HI.
ON Ford cars and Suv's,
Some times the sound chime after the seat belt buklet.
Is like a open door.
The problem on this car is that the the DOOR AJAR SWITCH. come danaged. and the Body cumputer don't recievethe door close signal.
But is intermitent.
The door ajar switch is on the door lacth.
You only can get front the dealer.
OK. I hope this information can be useful for you.

Thank you.