Some 2020 Mustang vehicles may exhibit a concern of the decklid not opening when it is attempted to be open when a valid key is within range of the vehicle. There may also be a concern where the horn gives a double chirp noise when locking the vehicle. This may be due to a fault with the body control module (BCM) software. Reprogram the BCM to correct this condition. Refer to Workshop Manual (WSM), Section 419-10. For claiming, use causal part 15604 and any applicable labor operations in Section 10 of the Service Labor Time Standards (SLTS) Manual.