DTC P024: Vehicle Speed Sensor (VSS) Circuit Problem: Action

1. PCM turns on the "SERVICE ENGINE SOON" MIL.
2. Cruise control is disabled for the entire ignition cycle.
3. Torque converter clutch is disabled.
4. The PCM will substitute a calculated vehicle speed based on the transaxle input speed and the current gear commanded (gear ratio).
5. PCM freezes transaxle in current gear.
6. Torque management is disabled.

NOTE: Numbers in list refer to circled numbers in diagnostic flow chart, see Fig 1. For circuit identification see Fig 2.

1. If Code P025 is current, the fault is present and can be diagnosed directly. If P025 is stored as history, use P075 to diagnose because fault is intermittent.
2. The vehicle speed sensor will generate a frequency of greater than 0 Hertz when spun by hand. If it does, the PCM is at fault. If it does not, check wires/sensor for opens and shorts.

Fig 1: DTC P024: Vehicle Speed Sensor Circuit Problem Flow Chart

Courtesy of GENERAL MOTORS CORP.

Fig 2: DTC P024: Vehicle Speed Sensor Circuit Problem Flow Chart Circuit

Courtesy of GENERAL MOTORS CORP.