vtec spool error

[NaturalSt8]

i have a 93 del sol with a b16a swap, p28ecu with hondata s300 v1. drivng my car i get no cel but definitely something going on with vtec. when i test output for vtec it gives me spool error code 21. i have replaced the solenoid and wiring harness and still same issue. it never throws a code while driving, never has. only when i test ouput it gives error code. can anyone point me in the right direction? thanks

[Spunkster]

Ignoring the error when you test, what exactly is the issue you are having?