This study aims to design and evaluate the performance of a motorcycle security system based on an Arduino Uno, using an R503 fingerprint sensor as the primary authentication method and a personal identification number (PIN) code as a backup mechanism. The hardware consisted of an Arduino Uno, R503 fingerprint sensor, keypad, relays, DFPlayer Mini, buzzer, speaker, and LM2596 step-down converter. The system performance was evaluated through component and functional testing of the fingerprint sensor under four finger-surface conditions (dry, oily, wet, and dusty), with four trials per condition. Contaminants were applied to the sensor surface using cooking oil (oily), water (wet), and household dust (dusty), which were evenly applied to the fingertip surface of the sensor. The performance was measured based on the recognition success rate and average response time, with a scan considered successful if the sensor returned a positive fingerprint match within the detection time-out. The results show that registered fingerprints were successfully recognized under dry, oily, and dusty conditions with an average recognition success rate of 100% and an average response time of 1.03–1.39 s (dry: 1.03 ± 0.10 s; oily: 1.39 ± 0.14 s; dusty: 1.29 ± 0.08 s), whereas the wet condition significantly reduced the recognition performance to 0% with a response time of 2.43 ± 0.10 s. When fingerprint authentication failed, the PIN successfully activated the manual-ignition function. These findings indicate that the combination of fingerprint and PIN authentication functions reliably as an alternative access mechanism under most tested conditions, although this study is limited to functional prototype testing and does not evaluate the resistance to real security attacks or the actual reduction in motorcycle theft incidents.