This study used the ARCS approach to investigate the effects of university students' motivation, including attention, relevance, confidence, and satisfaction, to use the Programming Teaching Assistant (PTA) on their Programming Problem-Solving Skills (PPSS). Previous studies have shown that PTA features enhance learners' programming performance, but relevant studies have not empirically evaluated the factors influencing learners' problem-solving skills in PTA-based programming language practice. Thus, the current study used the ARCS model to investigate the effects of its core factors, Attention (A), Relevance (R), Confidence (C), and Satisfaction (S), on the learners' PPSS. A total of 99 students major in computer science and engineering (CSE) participated in this study. Multiple linear regression analysis was conducted and the results indicated that these motivational factors influenced learners' PPSS in PTA-based programming language practice. The PTA has proven to be a motivating platform for programming language practice. Finally, relevant implications are offered.