Code 24 (MFI CALIF. & New YORK) - Vehicle Speed Sensor: Notes

ECM provides 5 volts to Vehicle Speed Sensor (VSS). While vehicle is moving, a reed switch inside VSS will open and close, toggling voltage signal high and low. ECM then converts this toggled high/low voltage into vehicle speed that is displayed as MPH/KPH. Code 24 will set if no VSS signal even though fuel has been cut for more than 5 seconds.

1. Checks if problem is intermittent.
2. If VSS is not receiving 5 volts from ECM, Code 24 will set. Checks for open or short to B+ in Yellow wire, or a faulty ECM.
3. Checks for a poor ground connection, an open in Black/Yellow wire or a faulty VSS.