DTC B27A1: Open in Driver Side Electrical Antenna Circuit [11/2015 - ]: Procedure

1. Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and front door outside handle assembly (for driver door).

   OK

   Connectors are properly connected.

   Result

   Proceed to
   OK
   NG

Result: 

NG 

CONNECT CONNECTORS PROPERLY 

Result: 

OK 

See step  2

1. Disconnect the M59 and F1 certification ECU (smart key ECU assembly) connectors.
2. Disconnect the J3 front door outside handle assembly (for driver door) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   M59-17 (CLG1) - J3-6 (ANT1)	Always	Below 1 Ω
   M59-16 (CG1B) - J3-4 (ANT2)	Always	Below 1 Ω
   F1-18 (E) - Body ground	Always	Below 1 Ω
   M59-17 (CLG1) or J3-6 (ANT1) - Body ground	Always	10 kΩ or higher
   M59-16 (CG1B) or J3-4 (ANT2) - Body ground	Always	10 kΩ or higher

4. Reconnect the M59 and F1 certification ECU (smart key ECU assembly) connectors.

   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
   M59-17 (CLG1) - F1-18 (E)	Procedure: Power switch off All doors closed Electrical key transmitter sub-assembly not inside vehicle All doors locked through wireless operation (electrical key transmitter sub-assembly brought inside detection area*)	5 V/DIV., 500 ms/DIV.	Pulse generation (See waveform 1)
   	Procedure: Power switch off All doors closed Electrical key transmitter sub-assembly not inside vehicle All doors locked through wireless operation (electrical key transmitter sub-assembly brought outside detection area*)	5 V/DIV., 100 ms/DIV.	Pulse generation (See waveform 2)
   M59-16 (CG1B) - F1-18 (E)	Procedure: Power switch off All doors closed Electrical key transmitter sub-assembly not inside vehicle All doors locked through wireless operation (electrical key transmitter sub-assembly brought inside detection area*)	5 V/DIV., 500 ms/DIV.	Pulse generation (See waveform 3)
   	Procedure: Power switch off All doors closed Electrical key transmitter sub-assembly not inside vehicle All doors locked through wireless operation (electrical key transmitter sub-assembly brought outside detection area*)	5 V/DIV., 100 ms/DIV.	Pulse generation (See waveform 4)

   HINT: 

   *: For details about the entry function detection area, refer to Operation Check.

   Refer to OPERATION CHECK [11/2015 - ]

   Result

   Proceed to
   OK
   NG

Result: 

NG 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [11/2015 - 12/2018]  , or refer to  REMOVAL [12/2018 - 07/2020]  , or refer to  REMOVAL [07/2020 - ] 

Result: 

OK 

See step  4

1. Replace the front door outside handle assembly (for driver door) with a new one or the front door outside handle assembly (for front passenger door) if it is functioning properly.

   HINT: 

   Refer to DISASSEMBLY [11/2015 - 12/2018] , or refer to DISASSEMBLY [12/2018 - 07/2020] , or refer to DISASSEMBLY [07/2020 - ]

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  5

1. Clear the DTCs.

   Body Electrical > Smart Key > Clear DTCs 

   Result

   Proceed to
   NEXT

Result: 

NEXT 

See step  6

1. Check for DTCs.

   Body Electrical > Smart Key > Trouble Codes 

   Result

   Result	Proceed to
   B27A1 is not output	A
   B27A1 is output	B

Result: 

A 

END (FRONT DOOR OUTSIDE HANDLE ASSEMBLY (FOR DRIVER DOOR) WAS DEFECTIVE) 

Result: 

B 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY). Refer to  REMOVAL [11/2015 - 12/2018]  , or refer to  REMOVAL [12/2018 - 07/2020]  , or refer to  REMOVAL [07/2020 - ]