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
(Some people have issue connecting. LEMON is investigating. For now, use Firefox or change your DNS server)
Or, hide this message:
temporarily or
permanently
Vehicle Speed Sensor: Description and Operation
Vehicle Speed Sensor Circuit:
PURPOSE The engine control module
(ECM) uses this signal to determine idle speed control, etc..
OPERATION The
vehicle speed sensor is a magnetic reed type switch.
-
As the speedometer cable turns, the switch turns ON and OFF (opening and closing the circuit) generating a pulsed a signal to be interpreted by the ECM as vehicle speed.
