Impreza L Sport Wagon F4-2.2L SOHC (1999)
Speedometer Head: Description and Operation
1. DESCRIPTION
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The speedometer system is an electric type; it uses electrical wire and drives the speedometer according to electrical signals from speed sensor
2 (MT model) or TCM (AT model).
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The speed sensor 2 is installed on the manual transmission.
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For this reason, meter trouble (meter hand vibration, cable disconnection, etc.) is eliminated and transmission mechanical noise is decreased.
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The odometer and trip meter are displayed by LCD (Liquid crystal display).
2. OPERATION
MT model: The speed sensor 2 sends the vehicle speed signal (4 pulses per one turn of speed sensor driven shaft) to the speedometer drive circuit
and odometer/trip meter drive circuit in the speedometer.
AT model: The TCM sends the vehicle speed signal (4 pulses) to the speedometer drive circuit and odometer/trip meter drive circuit in the
speedometer.
NOTE: The output signal from speed detection circuit is also used in engine control module, automatic transmission control module, etc.
3. SYSTEM DIAGRAM