P1791
Vehicle Speed Sensor Range/Performance Problem
Severity
⚠️ MediumCan you drive?
Limited driving only, diagnose soon
Approx. repair cost
$6–33 (est.)
Symptoms
- Incorrect speedometer readings
- Gear shifting problems
- Cruise control not working
- Check Engine Light Illuminates
- Increased fuel consumption
Causes
- Speed sensor (VSS) malfunction
- Open or short circuit in the sensor circuit
- Poor contact in the sensor connector
- Damage to the sensor drive mechanism
- Problems with the ECU
How to Fix
- Check the integrity of the sensor wiring and connectors
- Test the speed sensor with a multimeter
- Check the sensor drive mechanism for damage
- Replace faulty speed sensor
- If necessary, diagnose the ECU