C 2500 Suburban 2WD V8-454 7.4L VIN J SFI (1998)
Audible Warning Device: Initial Inspection and Diagnostic Overview
The Overspeed Warning Alarm is sounded when the vehicle exceeds 120 km/h. This speed is not adjustable, and it is based on a frequency signal sent
from the vehicle control module on DK GRN (389). This signal is also sent to the Instrument Cluster for the speedometer/odometer function.