Apple is looking to expand its CarPlay interface reach within cars. The company is working on technology that would access functions like the climate-control system, speedometer, radio and seats, according to people with knowledge of the effort. The initiative, known as “IronHeart” internally, is still in its early stages and would require the cooperation of automakers. The iPhone-based system could access a range of controls, sensors and settings. That includes: inside and outside temperature and humidity readings; Temperature zones, fans and the defroster systems; Settings for adjusting surround-sound speakers, equalizers, tweeters, subwoofers, and the fade and balance; Seats and armrests; The speedometer, tachometer and fuel instrument clusters. By gaining access to controls and instruments, Apple could turn CarPlay into an interface that could span nearly the entire car. The data also could be used by Apple or third parties to create new kinds of apps or add features to existing functions. Some Apple users have complained about the need to jump between CarPlay and a car’s built-in system to manage key controls. This initiative would alleviate that friction.