Circuit Description
Vehicle speed values are provided by the vehicle speed sensor (VSS). The sensor
is a permanent magnet variable reluctance sensor (VRS) mounted on the differential
area of the transaxle housing. The PM generator produces a pulsing voltage whenever
vehicle speed is above 5 km/h (3 mph). These pulses occur 16 times
per each revolution of the differential housing and are translated to provide vehicle
speed in miles per hour.
Conditions for Setting the DTC
Important: The VSS signal is continuously checked once
the following conditions are met. If the VSS signal is missing, the speedometer will
be inoperative.
DTC P0500 will set if there is no VSS signal when:
| • | The engine speed is between 1,400-4,000 RPM. The MAP sensor
indication is less than 0.5 volts, or less than 23 kPa (3 psi),
for greater than 5 seconds. |
| • | The vehicle is not in park/neutral for an automatic transaxle. |
Diagnostic Aids
| • | The speedometer will not work if the VSS subsystem has failed. |
| • | If the VSS reading is accurate and the speedometer is incorrect, refer
to the Audio System or Instrument Panel, Gages, and Console sections. |
| • | The VSS resistance is 800-1,600 ohms. |
| • | If the problem is intermittent, wiggle the wires while monitoring the
VSS signal on the scan tool and watch for the signal to jump for a loss of signal. |
| • | The PCM will calculate VSS based on RPM and the TP sensor signal if DTC P0500
is set, but the speedometer will remain inoperative. |
