DTC B27A7: Open in Inside Luggage Compartment Electrical Key Oscillator Circuit [08/2015 - 08/2019]: Procedure

1. Turn the engine switch off.
2. Check that the connectors are properly connected to the certification ECU and indoor No. 2 electrical key antenna (inside luggage).

   OK

   Connectors are properly connected.

Result: 

NG 

CONNECT CONNECTORS PROPERLY 

Result: 

OK 

See step  2

1. Disconnect the O14 antenna connector.
2. Disconnect the F79 ECU connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   O14-1 (CLG6) - F79-26 (CLG7)	Always	Below 1 Ω
   O14-3 (CLGB) - F79-27 (CG7B)	Always	Below 1 Ω
   F79-26 (CLG7) - Body ground	Always	10 kΩ or higher
   F79-27 (CG7B) - Body ground	Always	10 kΩ or higher
   F79-15 (E) - Body ground	Always	Below 1 Ω

Result: 

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result: 

OK 

See step  3

1. Measure the voltage according to the value(s) in the table below.

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   TEXT IN ILLUSTRATION
   
   

   *a

   Component with harness connected (Certification ECU)

   -

   -

   OK

   Tester Connection	Switch Condition	Specified Condition
   F79-26 (CLG7) - F79-15 (E)	Engine switch off, all doors closed, key not in cabin and lock sensor off → on	No pulse generation → Pulse generation
   F79-27 (CG7B) - F79-15 (E)	Engine switch off, all doors closed, key not in cabin and lock sensor off → on	No pulse generation → Pulse generation

Result: 

NG 

REPLACE CERTIFICATION ECU 

(Refer to REMOVAL [08/2015 - 08/2019] )

Result: 

OK 

See step  4

1. Temporarily replace the indoor No. 2 electrical key antenna (inside luggage) with a new or normally functioning one (Refer to REMOVAL [08/2015 - ] ).

Result: 

NEXT 

See step  5

1. Clear the DTCs (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).
2. Check for DTCs (Refer to DTC CHECK / CLEAR [08/2015 - 08/2019] ).

   OK

   DTC B27A7 is not output.

Result: 

OK 

END (INDOOR NO. 2 ELECTRICAL KEY ANTENNA ASSEMBLY IS DEFECTIVE) 

Result: 

NG 

REPLACE CERTIFICATION ECU 

(Refer to REMOVAL [08/2015 - 08/2019] )