Vehicle speed output

WARNING: This page is about a different car, the 2005 Mazda 6. However, it is still accessible from the selected car via links, so may be relevant.

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
Courtesy of MAZDA MOTORS CORP.