2000 V70 XC AWD love this car, 115000 miles great shape
this is the first and only ever volvo, ... just got it, .... never touched one before
Total newby to volvo so please tolerate newby questions

got a P1618 code, check engine and flashing up arrow
I installed new Pnp swich from Volvo didn't correct P1618
ATF filler tube was left out during pnp switch replacement, lost 4 quarts of atf, so low it would not drive at all, topped it up with 2 quarts non 3309 (Philips 66 atf) plus 2 qts CAstrol synthetic all vehicle that meets 3309 spec

Question: Am i on thin ice to drive it around like this? Two questions:

with:
1- The mixed ATF is one of two possible problems.
or
2- Driving with the flashing arrow is another.

I've read a lot of kind of vague information on the boards about these Volvo transmissions from catastrophy stories about the wrong atf to other stories ...

3309 spec ATF seems easy to find now Castrol synthetic multi vehicle is less than $8

Thanks in advance.