Mazda 1990 323 Workshop Manual Supplement page 231

TROUBLESHOOTING GUIDE
K2
Resistance: 13-273
* If OK, go to next step
6 If not OK, repair wiring
12V to 2E, 2G, 21 and 2K terminals and
if operation sound (clicking) of solenoid is
Apply 12V to 2K terminal of EC-AT control unit
start engine in P range and let it ide
Shift to D range and check if engine stalls
No Replace lockup solenoid valve
K2-55