Operation CHARM: Car repair manuals for everyone.

Speedometer

The speedometer is a road speed indicator. All Instrument Clusters are equipped with both a trip odometer and a season odometer. A Vehicle Speed Sensor (VSS) (permanent magnet generator) located on the transaxle inputs to the Powertrain Control Module (PCM) whenever the trans axle differential carrier turns. The PCM then buffers the VSS signal and transmits it to the IPC, the Electronic Brake Control Module (EBCM), and the Sensing Diagnostic Module (SDM) at 4000 pulses/mile via a hardwired connection (CKT 817).