if im correct and this is a GE EV100 or a GE SX (the motor control system in the back) then a -16 error means "battery volts too high"
you may have inadvertently reset the control card

if its a diff system im wrong and dont listen to me lol but im pretty sure those clarks with self diagnostics use GE control systems
write down the proper model and serial # and post it 2morrow after work

if im right youll need to have some1 with a handset come out and reset it (function 15)