Operation CHARM: Car repair manuals for everyone.
Manuals through 2025 now available!

Our trusted friends have launched a new website named LEMON, which has newer manuals. It also contains all the CHARM manuals.

LEMON is the spiritual successor to CHARM, I recommend you try it!

Link: lemon-manuals.la or lemon-manuals.org.ua

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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.