Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
Code 24 Vehicle Speed Sensor (VSS) - 2.0L & 2.5L TBI: Notes
Vehicle speed information is provided to the ECM by the vehicle speed sensor. which is a permanent magnet (PM) generator, and is mounted in the transaxle. The PM generator produces a pulsing voltage, whenever vehicle speed is over about 3 MPH. The AC voltage level and the number of pulses increases with vehicle speed. The ECM then converts the pulsing voltage to MPH, which is used for calculations, and the MPH can be displayed with a SCAN tool.
The function of VSS buffer used in past model years has been incorporated into the ECM. The ECM then supplies the necessary signal for the instrument panel (4000 pulses per mile) for operating speedometer and odometer. If vehicle is equipped with cruise control, ECM also provides a signal (2000 pulses per mile) to cruise control module.
- Code 24 will set it vehicle speed equals 0 MPH when engine speed is between 1400 and 3500 RPM, TPS is less than 2%, low load condition (low MAP voltage, high manifold vacuum), not in park or neutral, all conditions met for 5 seconds. These conditions are met during a road load deceleration. Disregard Code 24 that sets when drive wheels are not turning. The PM generator only produces a signal if drive wheels are turning greater than 3 MPH.
- Check Mem-Cal for proper application before replacing ECM.
NO RELATED
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
Affiliate disclosure: We may earn a commission at no extra cost to you.
When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.