DTC B27A7: Open in Inside Luggage Compartment Electrical Key Oscillator Circuit (07/2015 -): Procedure

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

   OK

   Connectors are properly connected.

Result:  NG

NG 

CONNECT CONNECTORS PROPERLY 

Result:  OK

OK 

See step  2

1. Disconnect the A36 and Q1 certification ECU (smart key ECU assembly) connectors.
2. Disconnect the Q25 NO. 1 indoor electrical key antenna assembly (inside luggage compartment) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   Q1-9 (CLG7) - Q25-1 (ANTE7)	Always	Below 1 Ω
   Q1-8 (CG7B) - Q25-3 (CLGB)	Always	Below 1 Ω
   A36-11 (E) - Body ground	Always	Below 1 Ω
   Q1-9 (CLG7) or Q25-1 (ANTE7) - Body ground	Always	10 kΩ or higher
   Q1-8 (CG7B) or Q25-3 (CLGB) - Body ground	Always	10 kΩ or higher

Result:  NG

NG 

REPAIR OR REPLACE HARNESS OR CONNECTOR 

Result:  OK

OK 

See step  3

1. Connect the A36 and Q1 certification ECU (smart key ECU assembly) connectors.

   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 Q25 NO. 1 indoor electrical key antenna assembly (inside luggage compartment) connector.
3. Using an oscilloscope, check the waveform.

   OK

   Tester Connection	Condition	Tool Setting	Specified Condition
   Q1-9 (CLG7) - A36-11 (E)	Procedure: Engine switch off Electrical key transmitter sub-assembly not inside vehicle All doors closed Driver door lock sensor not touched → touched	2 V/DIV., 500 ms/DIV.	Pulse generation (See waveform)
   Q1-8 (CG7B) - A36-11 (E)	Procedure: Engine switch off Electrical key transmitter sub-assembly not inside vehicle All doors closed Driver door lock sensor not touched → touched	2 V/DIV., 500 ms/DIV.	Pulse generation (See waveform)

Result:  NG

NG 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 

(Refer to REMOVAL (07/2015 -) )

Result:  OK

OK 

See step  4

1. Temporarily replace the NO. 1 indoor electrical key antenna assembly (inside luggage compartment) with a new or known good one (Refer to REMOVAL (07/2015 -) ).

Result:  NEXT

NEXT 

See step  5

1. Clear the DTCs (Refer to DTC CHECK / CLEAR (07/2015 -) ).

Result:  NEXT

NEXT 

See step  6

1. Check for DTCs (Refer to DTC CHECK / CLEAR (07/2015 -) ).

   OK

   DTC B27A7 is not output.

Result:  OK

OK 

END (NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY (INSIDE LUGGAGE COMPARTMENT) WAS DEFECTIVE) 

Result:  NG

NG 

REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) 

(Refer to REMOVAL (07/2015 -) )