I dont have a manual for D80s-5 but for a D70-5 the faults are as follows.

D4 5820 3 HIGH VOLTAGE AT
BATTERY
measured voltage at
power supply is higher
than 18 V (12V device)
higher than 32.5 V (24V
device)
shift to neutral
OP-Mode:
TCU shutdown
z check power supply
battery
z check cables from
batteries to TCU
z check connectors
from batteries to
TCU
D5 5830 2 ERROR AT VALVE
POWER SUPPLY VPS1
TCU switched on VPS1
and measured VPS1 is
off or TCU switched off
VPS1 and measured
VPS1 is still on
cable or connectors are
defect and are contacted
to battery voltage
cable or connectors are
defect and are contacted
to vehicle ground
permanent power supply
KL30 missing
TCU has an internal defect
shift to neutral
OP-Mode:
TCU shutdown
z check fuse
z check cables from
gearbox to TCU
z check connectors
from gearbox to
TCU
z replace TCU
D6 5840 2 ERROR AT VALVE
POWER SUPPLY VPS2
TCU switched on VPS2
and measured VPS2 is off
or TCU switched off VPS2
and measured VPS2 is still
on
z cable or connectors are
defect and are contacted
to battery voltage
z cable or connectors are
defect and are contacted
to vehicle ground
z permanent power supply
KL30 missing
z TCU has an internal
defect
shift to neutral
OP-Mode:
TCU shutdown
z check fuse
z check cables from
gearbox to TCU
z check connectors
from gearbox to
TCU
z replace TCU