whats code 21???for a JDM b16 w/ PR3 ecu

my ecu keeps flashing code 21 and i cant find anywhere what that code is. i took it to honda and they said they have never seen it before, since they only deal with USDM motors. anyone know what it exactly is? ive gotten 3 different answers but no one has been sure. so if anyone know what code 21 is for sure…PLEASE tell me, thanks.

Code 21 is VTEC Solenoid valve.

Defective Circuit, Unplugged or Defective Solenoid

My teg is spitting that code too. Thanks for the info

yea, thanks someone emailed me with the problem. i had accidentally wired my solenoid to the oil switch negative. so what i then did was grounded the oil switch negative and then wired to solenoid to a wire that was hanging around and it too care of the problem. thanks guys