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Vehicle speed output

ABS/TCS HU/CM terminal: V(+) - AC (-)
Oscilloscope setting: 1 V/DIV (Y), 5 ms/DIV (X), DC range
Vehicle condition: Driving 30 km/h (18.6 mph)
NOTE:
- As vehicle speed increases, the wave period shortens.
Fig 1: Identifying Vehicle Speed Output Oscilloscope Pattern
Courtesy of MAZDA MOTORS CORP.