Q: module or unit?

Hi there. From the description you have provided, your vehicle Check Engine Light on with lots of warnings and exterior lighting acting weird, sounds like there may be a charging system related problem. I would recommend not driving your vehicle until, the problem is resolved. Given all of the symptoms, it could be, the alternator is overcharging. The higher voltage could cause multiple component failures. Left undiagnosed and repaired could result in expensive repairs. I recommend having your vehicle’s Check Engine Light be diagnosed and repaired by a certified technician, such as one from YourMechanic.