Envoy 2WD V8-5.3L VIN P (2004)
Amplifier: Description and Operation
AMPLIFIER
The amplifier in early build vehicles is a class 2 device that communicates with the scan tool on the Class 2 bus. The Class 2 amplifier will set a U100 in
the radio if there is a communication problem. The late build vehicles have a NON-Class 2 amplifier that does not communicate over the Class 2 bus and
therefore the NON-Class 2 amplifier will not set codes. Both amplifiers have similar operating characteristics, therefore, there are not separate
diagnostics for the NON-Class 2amplifier.
