For 3YC1DG6T7FY565964 the sum is 458, modulo is 4. for 5HVA1C6ZXPA702445 the modulo is 7. You should revise your code.

First example: translated "38314763768565964" =>

3 * 8 = 24

8 * 7 = 56

3 * 6 = 18

1 * 5 = 5

4 * 4 = 16

7 * 3 = 21

6 * 2 = 12

3 * 10 = 30

7 * 0 = 0

6 * 9 = 54

8 * 8 = 64

5 * 7 = 35

6 * 6 = 36

5 * 5 = 25

9 * 4 = 36

6 * 3 = 18

4 * 2 = 8

24+56+18+5+16+21+12+30+0+54+64+35+36+25+36+18+8 = 458

Can you post the VIN number? Did it happen on the Random Tests or Fixed Tests?