摘要：Penelitian bertujuan untuk: (1) meningkatan keaktifan belajar siswa; dan (2) meningkatkan hasil belajar kelistrikan kendaraan ringan siswa kelas XI TKR. Penelitian ini merupakan Penelitian Tindakan Kelas yang terdiri dari 3 siklus, masing-masing siklus terdiri dari empat tahapan yaitu: (1) Perencanaan tindakan; (2) Pelaksanaan tindakan; (3) Observasi; dan (4) Refleksi. Subjek penelitian adalah siswa kelas XI TKR 1 SMK Giripuro Sumpiuh yang berjumlah 42 siswa, objek penelitian adalah keaktifan dan hasil belajar sistem kelistrikan kendaraan ringan. Teknik analisis data menggunakan analisis kuantitatif. Hasil penelitian menunjukan bahwa penerapan model pembelajaran discovery learning dapat meningkatkan keaktifan dan hasil belajar kelistrikan kendaraan ringan siswa kelas XI TKR 1 SMK Giripuro Sumpiuh. Peningkatan keaktifan belajar dapat dilihat dari nilai rata-rata keaktifan siklus I sebesar 52,38%, siklus II sebesar 64,29%, dan 74,79% pada siklus 3, persentase keaktifan siklus I ke siklus II meningkat sebesar 11,19%, dan siklus II ke siklus III meningkat sebesar 10,50%. Peningkatan hasil belajar dilihat dari nilai ratarata siklus I sebesar 47,62%, siklus II sebesar 64,29%, dan 88,10% pada siklus III, persentase peningkatan hasil belajar siswa dari siklus I ke siklus II sebesar 16,67%, dan siklus II ke siklus III meningkat sebesar 23,81%. This study aims to: (1) improve the students’ learning activeness; and (2) increase the students’ learning outcomes of light vehicles electricity system of grade XI students of Light Vehicle Engineering. This study is a Classroom Action Research/Penelitian Tindakan Kelas consisting of 3 cycles in which each cycle comprises four stages: (1) Action planning; (2) Implementation of action; (3) Observation; and (4) Reflection. The subjects of the study were 42 students of grade XI of Light Vehicle Engineering (TKR) 1 class in Giripuro Sumpiuh Vocational High School. Meanwhile, the research object was the students’ activeness and learning outcomes of the light vehicles electrical system. Data analysis technique used was quantitative analysis. The result shows that the application of discovery learning model can improve the students’ activeness and learning outcomes of light vehicles electrical system of grade XI students of Light Vehicle Engineering (TKR) 1 class in Giripuro Sumpiuh Vocational High School. The improvement of the learning activeness can be seen from the average of the activeness of cycle I of 52.38%, cycle II of 64.29%, and cycle III of 74.79%, with the percentage of activeness in cycle I to cycle II increases by 11.19% and in cycle II to cycle III increases by 10.50%. The increase of learning outcomes is seen from the average score of cycle I of 47.62%, cycle II of 64.29%, and cycle III of 88.10%, with the percentage of the increase in students’ learning outcomes from cycle I to cycle II increases by 16.67%, and cycle II to cycle III increased by 23.81%.
