Insert the key into the ignition switch (LOCK position), then measure changes in voltage between the antenna connector and the chassis ground.
Connector & terminal
(B415) No. 1 (+) — Chassis ground (−):
Is the maximum voltage more than 40 V? (Approx. 0.1 second after inserting the key) Is the voltage 0 V? (Approx. 1 second after inserting the key)
Replace the body integrated unit Register all ignition keys (transponders). Refer to the “PC application help for Subaru Select Monitor”.