DTC B27A7: Open in Inside Luggage Compartment Electrical Key Oscillator Circuit [10/2018 - ]: Procedure
WARNING: This page does not describe the selected car, but rather 6 other vehicles, including the 2024 Lexus UX 250h, 2023 Lexus UX 250h, 2022 Lexus UX 250h, 2021 Lexus UX 250h, and 2020 Lexus UX 250h. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK CONNECTOR CONNECTION
- Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and No. 1 indoor electrical key antenna assembly (inside luggage compartment).
OK
Connectors are properly connected.
Result
Proceed to OK NG
Result:
NG
CONNECT CONNECTORS PROPERLY
Result:
OK
See step 2
- Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and No. 1 indoor electrical key antenna assembly (inside luggage compartment).
- CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT))
- Disconnect the N61 certification ECU (smart key ECU assembly) connector.
- Disconnect the N32 No. 1 indoor electrical key antenna assembly (inside luggage compartment) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition N61-11 (CLG7) - N32-1 (ANTE7) Always Below 1 Ω N61-10 (CG7B) - N32-3 (CLGB) Always Below 1 Ω - Reconnect the N61 certification ECU (smart key ECU assembly) connector.
Result
Proceed to OK NG
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 3
- CHECK CERTIFICATION ECU (OUTPUT TO NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT))
*a Component with harness connected
(Certification ECU (Smart Key ECU Assembly))*b Waveform 1 *c Driver door lock sensor not touched *d Driver door lock sensor touched - Using an oscilloscope, check the waveform.
OK
Tester Connection Condition Tool Setting Specified Condition N61-11 (CLG7) - F44-18 (E) Procedure: - Door is closed
- Power switch off
- Electrical key transmitter sub-assembly not inside vehicle
- Driver door lock sensor touched
2 V/DIV., 500 ms./DIV. Pulse generation
(See waveform 1)N61-10 (CG7B) - F44-18 (E) Procedure: - Door is closed
- Power switch off
- Electrical key transmitter sub-assembly not inside vehicle
- Driver door lock sensor touched
2 V/DIV., 500 ms./DIV. Pulse generation
(See waveform 1)Result
Proceed to OK NG
Result:
OK
REPLACE NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT). Refer to REMOVAL [10/2018 - ]
Result:
NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL [10/2018 - 07/2022] Refer to REMOVAL [07/2022 - ]
- Using an oscilloscope, check the waveform.