Acura Integra 1998 Service Manual page 1452

- How the Circuit Works
With the ignition switch in ON (ll) or START (lll),
battery voltage is supplied through fuse 15 and the
BLK//EL wire to the vehicle speed sensor (VSS).
The sensor is grounded by the BLK wire to G101.
The speedometer and other control units in the
circuit supply about 5 volts to the ORN wire. The
vehicle speed sensor (VSS) intermittently
grounds
the ORN wire which generates a pulsed signal in it.
The number of pulses per minute increases/
decreases with the speed of the car
Refer to the Service Manual (Section 23, Electrical)
for specific tests or troubleshooting
procedures.
33-1