@amandaj35820 this is usually battery related. The contacts for the battery temperature sensor are near the top of the charger. Try to attach the wireless charger to the phone. Once it is connected try to turn the phone on. If your wireless charging pad has failed, you an also get the same message. In your case, I'd start with a new battery.
+
@amandaj35820 this is usually battery related. The contacts for the battery temperature sensor are near the top of the charger. Try to attach the wireless charger to the phone. Once it is connected try to turn the phone on. If your wireless charging pad has failed, you an also get the same message. In your case, I'd start with a new battery. Use these guides https://www.ifixit.com/Device/Samsung_Galaxy_S8_Plus to work on your phone.
@amandaj35820 this is usually battery related. The contacts for the battery temperature sensor are near the top of the charger. Try to attach the wireless charger to the phone. Once it is connected try to turn the phone on. If your wireless charging pad has failed, you an also get the same message. In your case, I'd start with a new battery.