Sierra 1500 4WD V8-5.3L VIN Z Flex Fuel (2005)
Speedometer Module: Description and Operation
SPEEDOMETER
The instrument panel cluster (IPC) displays the vehicle speed on the analog speedometer based on the vehicle speed signal from the powertrain control
module (PCM). The PCM converts the data from the vehicle speed sensor to a 4,000 pulses/mile signal. The IPC uses the vehicle speed signal circuit
from the PCM in order to calculate the vehicle speed.
The speedometer defaults to 0 km/h (0 mph) if a malfunction in the vehicle speed signal circuit exists.
