DTC B27A7: Open in Inside Luggage Compartment Electrical Key Oscillator Circuit: Procedure

1. Turn the power switch off.
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 floor).

   OK

   Connectors are properly connected.

NG → CONNECT CONNECTORS PROPERLY 

OK: Go to next step 

1. Disconnect the G53 and G55 certification ECU (smart key ECU assembly) connectors.
2. Disconnect the M16 No. 3 indoor electrical key antenna assembly (rear floor) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   G53-4 (CLG7) - M16-1 (ANTE7)	Always	Below 1 Ω
   G53-3 (CG7B) - M16-3 (CLGB)	Always	Below 1 Ω
   G55-1 (E) - Body ground	Always	Below 1 Ω
   G53-4 (CLG7) or M16-1 (ANTE7) - Body ground	Always	10 kΩ or higher
   G53-3 (CG7B) or M16-3 (CLGB) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Connect the G53 and G55 certification ECU (smart key ECU assembly) connectors.
   Fig 1: G53 And G55 Certification ECU (Smart Key ECU Assembly) Connectors & Waveform

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
   TEXT IN ILLUSTRATION
   
   

   *1	Waveform	-	-
   *a	Component with harness connected (Certification ECU (smart key ECU assembly))	*b	Before driver door lock sensor touched
   *c	After driver door lock sensor touched	-	-

2. Connect the M16 No. 3 indoor electrical key antenna assembly (rear floor) connector.
3. Using an oscilloscope, check the waveform.

   OK

   Tester Connection	Switch Condition	Tool Setting	Specified Condition
   G53-4 (CLG7) - G55-1 (E)	Proceed: Power switch off Electrical key transmitter sub-assembly not inside vehicle Door is open Door is closed Within 30 seconds	2 V/DIV., 500 ms/DIV.	Pulse generation (See waveform)
   G53-3 (CG7B) - G55-1 (E)	Proceed: Power switch off Electrical key transmitter sub-assembly not inside vehicle Door is open Door is closed Within 30 seconds	2 V/DIV., 500 ms/DIV.	Pulse generation (See waveform)

NG → See step   7 

OK: Go to next step 

1. Temporarily replace the No. 3 indoor electrical key antenna assembly (rear floor) with a new or known good one. Refer to REMOVAL .

NEXT: Go to next step 

1. Clear the DTCs. Refer to DTC CHECK / CLEAR .

NEXT: Go to next step 

1. Check for DTCs. Refer to DTC CHECK / CLEAR .

   OK

   DTC B27A7 is not output.

NG → See step   7 

OK → END (NO. 3 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (REAR FLOOR) WAS DEFECTIVE)