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Home >> Lexus >> 2025 >> NX 350h >> Repair and Diagnosis >> External Pages >> Different car >> Section 59 (Smart Access System (For Start) - Diagnostic Codes & Symptom Tests (1 Of 2)) >> SMART ACCESS SYSTEM WITH PUSH-BUTTON START (for Start Function, Gasoline Model) >> DTC B27A7-13: Rear Floor 2 Electrical Key Oscillator Circuit Open [11/2021 - ] >> Description

DTC B27A7-13: Rear Floor 2 Electrical Key Oscillator Circuit Open [11/2021 - ]: Description

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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 in the cabin, the signal from the certification ECU (smart key ECU assembly) requesting a response from the electrical key transmitter sub-assembly is transmitted inside the vehicle. DTC B27A7-13 is stored by the certification ECU (smart key ECU assembly) when an open 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 No. Detection Item DTC Detection Condition Trouble Area DTC Output from Priority Note
B27A7-13 Rear Floor 2 Electrical Key Oscillator Circuit Open An open 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*).
  • Certification ECU (smart key ECU assembly)
  • No. 3 indoor electrical key antenna assembly (inside luggage compartment)
  • Harness or connector
 Smart Access A DTC Output Confirmation Operation: 
  1. Any time
  1. *: 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 electrical key transmitter sub-assembly is in rear floor:
  • Power source mode does not charge when engine switch pressed
  • Electrical key transmitter sub-assembly locked inside vehicle
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RELATED DATA LIST AND ACTIVE TEST

DTC No. Data List and Active Test
B27A7-13 Key diagnostic mode can be used to perform troubleshooting
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