No Vehicle Speed Sensor Signal

Name of Code:
No Vehicle Speed Sensor Signal

When Monitored:
With the engine running more than 31 seconds, engine temperature greater than 120°F, transmission not in park or neutral brakes not applied. engine rpm greater then 1,800, and MAP vacuum less than 10".

Set Condition:
No signal from the vehicle speed sensor (TCM) is present for more than 6 seconds.

Theory of Operation:
The vehicle speed sensor signal is provided to the PCM by the Transmission control Module (TCM). The signal is calculated by the TCM based on the output speed sensor signal and the speedometer pinion factor. The PCM provides a 5-volt pull-up signal from cavity 86 to TOM cavity 58. The sensor signal is created by the TCM alternating the signal from 5V to 0.3V.

Possible Causes:
- Open or shorted signal circuit
- Speedometer pinion factor not programmed
- Output speed sensor circuit problem
- Failed PCM
- Failed TCM