1997 E420, 55K miles. Using the original master key (switch blade style, with central locking system IR transmitter), starter engages and spins motor readily but ignition system apparently disabled and engine fails to start.

Using a spare master (blade only, no transmitter or battery; obtained from M-B) motor starts readily.

Will renewing the battery in the original master key remedy this problem or is this related to a fault in the key's security chip. requiring renewal of the master key?