The speedo on your Mazda 3 is not working you have checked the fuses and had the PCM checked?

If the speedometer on your Mazda 3 is not working after checking the fuses and the PCM, the issue may be with the vehicle speed sensor (VSS), which sends speed information to the speedometer. Additionally, check the wiring and connectors leading to the sensor for damage or corrosion. If those components are functioning properly, it may be necessary to inspect the instrument cluster itself for faults. Consider consulting a professional mechanic for further diagnosis.