Code 24: Vehicle Speed Sensor (VSS): Notes

The Vehicle Speed Sensor (VSS) is a PM generator type located in the transmission or transaxle. As the vehicle moves, the generator creates AC voltage signal which is routed to the buffer inside the ECM. In the buffer, the AC signal is changed from a "sine wave" to a "square wave" and amplified. The "square wave" is an on/off signal. The length of time between pulses determines vehicle speed.

1. Code 24 will set if vehicle speed equals less than 3 MPH when the following conditions occur:
   • Engine is running.
   • Vehicle is in high gear.
   • No Code 29 or 31 is present.
   • All conditions met for 40 seconds.
2. Before replacing ECM, check MEMCAL for proper application.