DTC 24

DTC 24 - Vehicle Speed Sensor (VSS) Circuit:

Vehicle Speed Sensor (VSS) Wiring Circuit:

Circuit Description:

Vehicle speed information is provided to the PCM by the vehicle speed sensor, in the transaxle. The voltage level and the number of pulses increases with vehicle speed. The PCM converts the pulsing voltage to mph, and the mph can be displayed with a Tech 1.

The function of the VSS buffer, used in past model years, has been incorporated into the PCM. The PCM supplies the necessary signal for the instrument panel (4004 pulses per mile) for operating the speedometer and the odometer.

DTC 24 will set if vehicle speed signal equals less than 3 mph when:
^ Engine is running.
^ No DTC 31.
^ Transmission is out of Park or Neutral (P/N) for more than 4 seconds.
^ Engine speed is greater than 3000 RPM.
^ All conditions met for 2 seconds.
OR
^ Vehicle speed goes from greater than 18 to 0 mph in less than 2 seconds, brake not applied.

NOTICE: If DTC 24 is set, the PCM will allow 2nd or 3rd gear only.

Test Description: Number(s) below refer to circled number(s) on the diagnostic chart.
1. The VSS signal generator only produces a signal if drive wheels are turning greater then 3 mph.
2. Before replacing the PCM, check the PROM for correct application.

Diagnostic Aids:

Tech 1 should indicate a vehicle speed whenever the drive wheels are turning greater than 3 mph.

Check CKTs 400 and 401 for proper connections to be sure they are clean and tight and the harness is routed correctly. - Intermittent Malfunctions