DTC B27A7 Open in Inside Luggage Compartment Electrical Key Oscillator Circuit |
| 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) (CLG7 - CLG6, CG7B - CLGB) (1 trip detection logic*). |
| Any time |
| Vehicle Condition when Malfunction Detected | Fail-safe Operation when Malfunction Detected |
When key is in luggage compartment:
| - |
| DTC Code | Data List and Active Test |
| B27A7 | Key diagnostic mode can be used to perform troubleshooting |

| 1.CHECK CONNECTOR CONNECTION |
Turn the power switch off.
Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and No. 3 indoor electrical key antenna assembly (inside luggage).
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| OK | |
| 2.CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - NO. 3 INDOOR ELECTRICAL KEY ANTENNA) |
Disconnect the H143 certification ECU (smart key ECU assembly) connector.
Disconnect the Q12 No. 3 indoor electrical key antenna assembly (inside luggage) connector.
Measure the resistance according to the value(s) in the table below.
| Tester Connection | Condition | Specified Condition |
| H143-26 (CLG7) - Q12-1 (CLG6) | Always | Below 1 Ω |
| H143-27 (CG7B) - Q12-3 (CLGB) | Always | Below 1 Ω |
| H143-15 (E) - Body ground | Always | Below 1 Ω |
| H143-26 (CLG7) or Q12-1 (CLG6) - Body ground | Always | 10 kΩ or higher |
| H143-27 (CG7B) or Q12-3 (CLGB) - Body ground | Always | 10 kΩ or higher |
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| OK | |
| 3.CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO NO. 3 INDOOR ELECTRICAL KEY ANTENNA [INSIDE LUGGAGE]) |
Connect the H143 certification ECU (smart key ECU assembly) connector.

| *1 | Waveform | - | - |
| *a | Component with harness connected (Certification ECU (smart key ECU assembly)) | *b | Door open |
| *c | After approximately 30 seconds from when the door is closed | - | - |
Connect the Q12 No. 3 indoor electrical key antenna assembly (inside luggage) connector.
Using an oscilloscope, check the waveform.
| Tester Connection | Switch Condition | Tool Setting | Specified Condition |
| H143-26 (CLG7) - H143-15 (E) | Procedure:
| 2 V/DIV., 500 ms/DIV. | Pulse generation (See waveform) |
| H143-27 (CG7B) - H143-15 (E) | Procedure:
| 2 V/DIV., 500 ms/DIV. | Pulse generation (See waveform) |
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| OK | |
| 4.REPLACE NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE) |
Temporarily replace the No. 3 indoor electrical key antenna assembly (inside luggage) with a new or normally functioning one (Click here).
| NEXT | |
| 5.CLEAR DTC |
Clear the DTCs (Click here).
| NEXT | |
| 6.CHECK FOR DTC |
Check for DTCs (Click here).
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| OK | ||
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