Code 24 - VSS Circuit: Notes

The ECM provides battery voltage to the Vehicle Speed Sensor (VSS), located behind instrument panel. The VSS alternately grounds circuit No. 437, which toggles the voltage high and low. This pulsed signal is used by the ECM to determine vehicle speed.

NOTE: Test numbers refer to test numbers on diagnostic chart.

Code 24 sets if vehicle speed equals 0 MPH when:
- Engine speed is between 1500-4400 RPM.
- TPS is at zero percent (closed throttle).
- MAP reads low voltage with high vacuum (low load condition).
- Transaxle not in Park or Neutral.
- Speed sensor indicates speeds less than 5 MPH.
- All conditions are met for 3 seconds.
These conditions are met during a road load deceleration. Disregard Code 24 that sets when drive wheels are not operating.