DTC B27A5: Open in Front Floor Electrical Key Oscillator Circuit [08/2015 - 08/2019]: Description

The certification ECU generates a request signal and transmits the signal to the indoor No. 1 electrical key antenna assembly (front floor). For the indoor No. 1 electrical key antenna assembly (front floor) to detect when the key is inside the vehicle, the signal from the certification ECU requesting a response from the key is transmitted inside the vehicle. DTC B27A5 is stored by the certification ECU when an open circuit is detected between the certification ECU and indoor No. 1 electrical key antenna assembly (front floor) (between terminals CLG5 and CLG3, or terminals CG5B and CLGB).

DTC Code	DTC Detection Condition	Trouble Area	DTC Output Confirmation Operation
B27A5	An open circuit is detected in the circuit between the certification ECU and indoor No. 1 electrical key antenna assembly (front floor) (CLG5 - CLG3, CG5B - CLGB) (1 trip detection logic*).	Harness or connector Indoor No. 1 electrical key antenna assembly (front floor) Certification ECU	Any time

*: Only output while a malfunction is present.

VEHICLE CONDITION AND FAIL-SAFE OPERATION WHEN MALFUNCTION DETECTED

Vehicle Condition when Malfunction Detected	Fail-safe Operation when Malfunction Detected
When key is in front seat area: Power source mode does not change when engine switch pressed Key locked inside vehicle	-

RELATED DATA LIST AND ACTIVE TEST

DTC Code	Data List and Active Test
B27A5	Key diagnostic mode can be used to perform troubleshooting