1) Prepare the Subaru Select Monitor kit.
2) Run the “PC application for Subaru Select Monitor”.
3) Read the data for ignition power supply voltage from Subaru Select Monitor.
4) Turn the ignition switch ON ←→ OFF.
Does the voltage change between 10 V or higher ←→ less than 1.5 V, matching the ignition switch ON ←→ OFF operation?
Check the ignition switch circuit.