Getting close... only got a single bit of error in the final checksum, but can't see how this is being caused.
The issue that the error is the same for all failing tests is a big clue. But why '00 00 00 00 00 00' works yet '00 00 00 00 00 80' doesn't, and then '00 01 30 00 2a 00' passes but '00 01 30 00 13 00' doesn't, but both with the same error perplexes me.
All test vectors supplied so far (sorted and de-duplicated) and my results....
Raw => Goes into CRC16 => Checksum
00 00 00 00 00 00 => 00 00 00 00 00 00 => b5 5f
00 00 00 00 00 01 => 00 00 00 00 00 01 => 94 4f
00 00 00 00 00 80 => 00 00 00 00 00 80 => 3d ce should be 3d cf, error 00 01
00 01 00 00 00 00 => 00 01 00 00 00 00 => e4 f5
00 01 30 00 13 00 => 00 01 30 00 13 00 => 2d 8f should be 2d 8e, error 00 01
00 01 30 00 2a 00 => 00 01 30 00 2a 01 => 01 20
00 01 30 00 41 00 => 00 01 30 00 41 00 => f0 e7
00 01 30 00 58 00 => 00 01 30 00 58 01 => 3a 4e should be 3a 4f, error 00 01
00 01 60 00 7e 00 => 00 01 60 00 7f 00 => 51 b4
00 01 60 00 80 00 => 00 01 60 00 81 00 => 9f 84 should be 9f 85, error 00 01
00 01 60 00 d7 01 => 00 01 60 00 d6 01 => 96 03
00 01 60 00 f3 01 => 00 01 60 00 f2 01 => b4 c9
00 01 70 01 22 01 => 00 01 70 01 23 00 => 14 d3
00 01 b0 00 20 00 => 00 01 b0 01 21 01 => f3 16
00 01 b0 01 20 00 => 00 01 b0 00 21 01 => c3 21
00 01 b0 02 53 00 => 00 01 b0 03 52 01 => 99 25 should be 99 24, error 00 01
00 01 b0 03 65 00 => 00 01 b0 02 64 01 => 9a bd should be 9a bc, error 00 01
00 01 b0 04 71 00 => 00 01 b0 05 70 01 => bd f7 should be bd f6, error 00 01
00 01 b0 05 75 00 => 00 01 b0 04 74 01 => 49 0c should be 49 0d, error 00 01
00 01 b0 06 65 00 => 00 01 b0 07 64 01 => 6a 56 should be 6a 57, error 00 01
00 01 b0 07 6e 00 => 00 01 b0 06 6f 00 => 81 ad
00 01 b0 08 63 00 => 00 01 b0 09 63 00 => dd c4 should be dd c5, error 00 01
00 01 b0 09 65 00 => 00 01 b0 08 65 00 => 4b 59 should be 4b 58, error 00 01
00 01 b0 0a 72 00 => 00 01 b0 0b 72 00 => ff 9a should be ff 9b, error 00 01
00 01 b0 0b 20 00 => 00 01 b0 0a 20 00 => 12 c5
00 01 b0 0c 36 00 => 00 01 b0 0d 36 00 => 57 e9
00 01 b0 0d 34 00 => 00 01 b0 0c 34 00 => 05 b8
00 01 b0 0e 20 00 => 00 01 b0 0f 20 00 => e2 2e
00 01 b0 0f 20 00 => 00 01 b0 0e 20 00 => d2 19
01 00 00 00 00 00 => 01 00 00 00 00 00 => 15 1a
01 00 20 01 01 01 => 01 00 20 01 01 01 => 7b 39 should be 7b 38, error 00 01
01 00 20 02 02 02 => 01 00 20 02 02 02 => 1b 05 should be 1b 04, error 00 01
01 00 20 03 03 03 => 01 00 20 03 03 03 => 3b 11 should be 3b 10, error 00 01
01 00 20 04 04 04 => 01 00 20 04 04 04 => db 7d should be db 7c, error 00 01
01 00 20 05 05 05 => 01 00 20 05 05 05 => fb 69 should be fb 68, error 00 01
01 00 20 06 06 06 => 01 00 20 06 06 06 => 9b 55 should be 9b 54, error 00 01
01 00 20 07 07 07 => 01 00 20 07 07 07 => bb 41 should be bb 40, error 00 01
01 00 20 08 08 08 => 01 00 20 08 09 08 => 6a bf should be 6a be, error 00 01
01 00 20 09 09 09 => 01 00 20 09 08 09 => 4a ab should be 4a aa, error 00 01
01 00 20 0a 0a 0a => 01 00 20 0a 0b 0a => 2a 97 should be 2a 96, error 00 01
01 00 20 0b 0b 0b => 01 00 20 0b 0a 0b => 0a 83 should be 0a 82, error 00 01
01 00 20 0c 0c 0c => 01 00 20 0c 0d 0c => ea ef should be ea ee, error 00 01
01 00 20 0d 0d 0d => 01 00 20 0d 0c 0d => ca fb should be ca fa, error 00 01
01 00 20 0e 0e 0e => 01 00 20 0e 0f 0e => aa c7 should be aa c6, error 00 01
01 00 20 0f 0f 0f => 01 00 20 0f 0e 0f => 8a d3 should be 8a d2, error 00 01
80 00 00 00 00 00 => 80 01 01 01 01 00 => 71 53