TrailBlazer 2WD L6-4.2L VIN S (2003)
Amplifier: Description and Operation
AUDIO AMPLIFIER
The audio amplifier is standard on some vehicle lines but is optional on most. The radio supplies low level audio signals to the audio amplifier in order
to boost the signal sent to the speakers. The class 2 signal circuit allows the radio to recognize that an amplifier is present. Once the radio detects an
audio amplifier, it will output low level audio signals. The audio amplifier is turned on when it receives a message via the class 2 serial data circuit
indicating that the radio is on.
