Also, from the product page the manual
https://mthtrains.com/sites/de...ction/30dl16171i.pdf
**** After you replace that 20 year old white battery**********************
Proto-Sound® is equipped with a microprocessor, that, depending on the
amount of memory it is allotted, allows the user to utilize several remotely
activated functions. In the simplest terms, Proto-Sound® has its own
“Computer" controlling these functions. In order to access many of these
remotely controlled functions, the user must be in the RESET state to do so.
RESET is entered anytime power to the locomotive has been off for more
than 3 to 5 seconds. When the engine first enters RESET, the
microprocessor initiates a system check to determine if the system,
transformer and engine are operating correctly. This takes approximately 5
seconds during which you will hear the engine’s startup sounds begin. In
order for Proto-Sound® to properly initiate the system check, do not
advance the transform er throttle past 10 volts when you first enter RESET,
wait for the diesel startup sounds to begin and then slowly turn the
transformer throttle to the off position and then back on again to enter the
forward phase. Interrupting the power too quickly may cause the system to
re-enter RESET (signaled by two dings of the bell). Should this happen,
wait longer before interrupting the power to enter the Forward phase.
