Several factors could lead to a Canon printer halting black ink output. Firstly, ensure the black ink cartridge isn't empty or improperly installed. Blocked printhead nozzles due to dried ink can hinder printing. Incorrect printer settings might also be a culprit, so verify settings like grayscale mode. Additionally, outdated printer drivers or firmware can cause issues. Faulty hardware components, like printheads or ink delivery systems, could also be to blame. Regular maintenance, such as printhead cleaning and firmware updates, can mitigate these issues, ensuring consistent black ink printing performance from your Canon printer.