Passive Haptic Learning (PHL) describes the learning of a motion, sequence or pattern without voluntary involvement of attention, focus or motivation through a haptic interface. In previous PHL studies about teaching Morse code, we suspect that active learning processes were at least partially involved in causing extraordinarily high learning rates. Therefore we conduct a similar, 50-participant user study to investigate whether PHL is able to teach Morse code without active attention. Our study design differs from previous studies by preventing active learning explicitly (no feedback given) and implicitly (non-Morse patterns, tests prevent learning by rule of elimination) for three groups. Two other groups get the same feedback as was present in other studies. Our results show much lower learning rates when there is no active learning possible. Including active learning, we replicate the same learning results as have been reported. This suggests that our suspicion was correct and that PHL of Morse Code is possible, but greatly limited. Further studies about PHL must pay attention to whether their study design allows participants to learn actively - even small amounts of information that is actively learned may have a great impact on learning performance.