DTC B27A7-13: Rear Floor 2 Electrical Key Oscillator Circuit Open [09/2023 - ]: Procedure
WARNING: This page is about a different car, the 2024 Lexus TX 550h+ and 2024 Lexus TX 500h. 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. 3 indoor electrical key antenna assembly (rear No. 2 seat).
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. 3 indoor electrical key antenna assembly (rear No. 2 seat).
- CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) - NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR NO. 2 SEAT))
Pre-procedure1
- Disconnect the I13 certification ECU (smart key ECU assembly) connector.
- Disconnect the P13 No. 3 indoor electrical key antenna assembly (rear No. 2 seat) connector.
- Measure the resistance according to the value(s) in the table below.
Standard Resistance
Tester Connection Condition Specified Condition Result I13-10 (CLG7) - P13-1 (ANTE7) Always Below 1 Ω Ω I13-9 (CG7B) - P13-2 (CLGB) Always Below 1 Ω Ω Result
Proceed to OK NG
Post-procedure1
- Connect the I13 certification ECU (smart key ECU assembly) connector.
Result:
NG
REPAIR OR REPLACE HARNESS OR CONNECTOR
Result:
OK
See step 3
- CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR NO. 2 SEAT))
- Using an oscilloscope, check the waveform.
*a Component with harness connected
(Certification ECU (Smart Key ECU Assembly))*b Waveform *c For 30 seconds after any door closed *d After 30 seconds or more have elapsed since any door closed OK
Tester Connection Condition Tool Setting Specified Condition I13-10 (CLG7) - D38-29 (E) Procedure: - Ignition switch off
- Electrical key transmitter sub-assembly not inside vehicle
- Within 30 seconds of closing any door
5 V/DIV., 500 ms./DIV. Pulse generation
(See waveform)I13-9 (CG7B) - D38-29 (E) Procedure: - Ignition switch off
- Electrical key transmitter sub-assembly not inside vehicle
- Within 30 seconds of closing any door
5 V/DIV., 500 ms./DIV. Pulse generation
(See waveform)Result
Proceed to OK NG
Result:
OK
REPLACE NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR NO. 2 SEAT). Refer to REMOVAL [09/2023 - ]
Result:
NG
REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to REMOVAL [09/2023 - 12/2023] , or refer to REMOVAL [12/2023 - ]
- Using an oscilloscope, check the waveform.