The infotainment screen that includes the rear backup camera stopped working intermittently and then completely. The dealer's service department identified that the APIM, a module involved in operating the screen had failed. The backup camera is a significant and necessary safety feature for such a large vehicle. The dealer ordered the new part and replaced it at significant expense. There was no warning of this issue, and the only symptom was the intermittent delay of the infotainment system turning on upon startup of the vehicle.