Panasonic KX-TD500 System Reference Manual page 1453

3.32 TSW additional OHCA failure
Error Code
Possible cause of
the malfunction
Countermeasures
Note
D 000
1) "TSW additional OHCA" is assigned to "Yes" in the System Assignment, but
TSW additional OHCA card is not installed.
No
Change the assignment
None
15-E-35
Do you use "OHCA" ?
Yes
Is the TSW additional card
installed ?
Yes
Replace the TSW card
End
No
Install the TSW additional card