Alarm Horn: Description and Operation

Theft Alarm Horn Activation Circuit:

Theft Alarm Horn Activation Circuit Continuity Table:

The ECU transistor is turned ON if the vehicle door, etc. are opened without use of the key.
This energizes the theft alarm horn relay to activate the horn.
Checking the horn activation circuit (Disconnect the connector of the ECU, then short-circuit terminal connector No. 58, and activate the theft alarm horn relay.)