Speedometer Head: Description and Operation
SPEEDOMETER1. DESCRIPTION
- The speedometer system is an electrical type that uses electric signals from the speed sensor in the MT model or the transmission control module (TCM) in the AT model.
- The vehicle speed sensor is installed on the manual transmission.
- Since the system does not use mechanical components such as rotating cable, there are no opportunities of occurring such problems as meter needle vibration and cable disconnection. Also, it does not constitute any means of mechanical noise transmission.
- The odometer and tripmeter readings appear on a liquid crystal display (LCD).
2. OPERATION
M/T model: The vehicle speed sensor sends vehicle speed signals (4 pulses per rotation of speed sensor's driven shaft) to the speedometer drive circuit and odometer/tripmeter drive circuit in the speedometer.
A/T model: The TCM sends vehicle speed signals (4 pulses per rotation of output shaft) to the speedometer drive circuit and odometer/tripmeter drive circuit in the speedometer.
NOTE: Signals from the speed sensor or TCM are also used by the engine control module, automatic transmission control module, etc.
System Diagram:
3. SYSTEM DIAGRAM