No Vehicle Speed Sensor Signal

WHEN MONITORED
With engine running longer than 31 seconds
Engine temperature greater than 120°F
Transmission not in park or neutral
Brakes not applied
Engine speed greater than 1800 RPM
And MAP vacuum less than 11"

SET CONDITION
No signal from the vehicle speed sensor for more than 11 seconds.

THEORY OF OPERATION
The vehicle speed sensor is a hall-effect type sensor used to detect the vehicle speed. The VSS signal is created when the sensor alternates the 5.0 volt pull up from high to low.

- The PCM calculates the vehicle speed based on the VSS signal.

PCM CONNECTIONS
- 8 volt supply to power up the sensor - PCM cavity 7.

- 5.0 volt pull up voltage - PCM cavity 47.

- Sensor ground - PCM cavity 4.

PROBABLE CAUSES
- Open or shorted signal circuit
- Speedometer pinion damaged
- Open 8-volt supply circuit
- Open sensor ground circuit
- Failed vehicle speed sensor
- Failed PCM