DTC B27A8: Open in Outside Luggage Compartment Electrical Key Antenna Circuit [12/2019 - 11/2023]: Procedure

1. Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and electrical key antenna (outside luggage compartment).

   OK

   Connectors are properly connected.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT CONNECTORS PROPERLY 

Result: 

OK 

See step  2

1. Disconnect the M5 certification ECU (smart key ECU assembly) connector.
2. Disconnect the M6 electrical key antenna (outside luggage compartment) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   M5-13 (CLG8) - M6-2 (ANTE8)	Always	Below 1 Ω
   M5-12 (CG8B) - M6-1 (CLGB)	Always	Below 1 Ω

4. Reconnect the M5 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

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

1. Using an oscilloscope, check the waveform.

   OK

   Tester Connection	Condition	Tool Setting	Specified Condition
   M5-13 (CLG8) - H48-18 (E)	Procedure: Ignition switch off Electrical key transmitter sub-assembly brought outside vehicle All doors closed Back door opener switch assembly off → on	2 V/DIV., 500 ms/DIV.	Pulse generation (See waveform 1)
   M5-12 (CG8B) - H48-18 (E)	Procedure: Ignition switch off Electrical key transmitter sub-assembly brought outside vehicle All doors closed Back door opener switch assembly off → on	2 V/DIV., 500 ms/DIV.	Pulse generation (See waveform 1)

   Result

   Proceed to
   OK
   NG

Result: 

OK 

REPLACE ELECTRICAL KEY ANTENNA (OUTSIDE LUGGAGE COMPARTMENT) 

Refer to REMOVAL [12/2019 - ]

Result: 

NG 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 

Refer to REMOVAL [12/2019 - 11/2023]