LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Lexus >> 2017 >> GS 450h Base >> Repair and Diagnosis >> Engine Mechanical >> Starter >> Smart Access System With Push-Button Start (For Entry Function) (Diagnostic Codes & Symptom Tests) >> SMART ACCESS SYSTEM WITH PUSH-BUTTON START(for Entry Function) >> Circuit Tests >> DTC B27A7: Open in Inside Luggage Compartment Electrical Key Oscillator Circuit [09/2014 - ] >> Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

DTC B27A7: Open in Inside Luggage Compartment Electrical Key Oscillator Circuit [09/2014 - ]: Description

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the No. 3 indoor electrical key antenna assembly (inside luggage compartment). For the No. 3 indoor electrical key antenna assembly (inside luggage compartment) to detect when the electrical key transmitter sub-assembly is inside the luggage compartment, the signal from the certification ECU (smart key ECU assembly) requesting a response from the electrical key transmitter sub-assembly is transmitted inside the luggage compartment. DTC B27A7 is stored by the certification ECU (smart key ECU assembly) when an open circuit is detected between the certification ECU (smart key ECU assembly) and No. 3 indoor electrical key antenna assembly (inside luggage compartment) (between terminals CLG7 and ANTE7, or terminals CG7B and CLGB).

DTC Code DTC Detection Condition Trouble Area DTC Output Confirmation Operation
B27A7 An open circuit is detected in the circuit between the certification ECU (smart key ECU assembly) and No. 3 indoor electrical key antenna assembly (inside luggage compartment) (CLG7 - ANTE7, CG7B - CLGB) (1 trip detection logic*).
  • Harness or connector
  • No. 3 indoor electrical key antenna assembly (inside luggage compartment)
  • Certification ECU (smart key ECU assembly)
Any time
VEHICLE CONDITION AND FAIL-SAFE OPERATION WHEN MALFUNCTION DETECTED

Vehicle Condition when Malfunction Detected Fail-safe Operation when Malfunction Detected
When electrical key transmitter sub-assembly is in luggage compartment:
  • Electrical key transmitter sub-assembly becomes locked inside vehicle
-
RELATED DATA LIST AND ACTIVE TEST

DTC Code Data List and Active Test
B27A7 Key diagnostic mode can be used to perform troubleshooting