DTC B27A5: Open in Front Floor 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 the No. 1 indoor electrical key antenna assembly (for front floor).

   OK

   Connectors are properly connected.

NG → CONNECT CONNECTORS PROPERLY 

OK: Go to next step 

1. Disconnect the certification ECU (smart key ECU assembly) connector.
2. Disconnect the No. 1 indoor electrical key antenna assembly (for front floor) connector.
3. Measure the resistance according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L62-7 (CLG5) - L11-1 (ANTE5)	Always	Below 1 Ω
   L62-8 (CG5B) - L11-3 (CLGB)	Always	Below 1 Ω
   L62-7 (CLG5) - Body ground	Always	10 kΩ or higher
   L62-8 (CG5B) - Body ground	Always	10 kΩ or higher
   L11-1 (ANTE5) - Body ground	Always	10 kΩ or higher
   L11-3 (CLGB) - Body ground	Always	10 kΩ or higher

NG → REPAIR OR REPLACE HARNESS OR CONNECTOR 

OK: Go to next step 

1. Reconnect the certification ECU (smart key ECU assembly) connector.
   Fig 1: Inspecting Certification ECU (Smart Key ECU Assembly) Connector Terminals

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Measure the resistance and check for pulses according to the value(s) in the table below.

   Standard Resistance

   Tester Connection	Condition	Specified Condition
   L62-15 (E) - Body ground	Always	Below 1 Ω

   Standard

   Tester Connection	Condition	Specified Condition
   L62-7 (CLG5) - L62-15 (E)	Power switch off All doors closed Key not in cabin Door outside handle assembly (lock sensor) not touched	No pulse generation
   L62-7 (CLG5) - L62-15 (E)	Power switch off All doors closed Key not in cabin Door outside handle assembly (lock sensor) touched	Pulse generation
   L62-8 (CG5B) - L62-15 (E)	Power switch off All doors closed Key not in cabin Door outside handle assembly (lock sensor) not touched	No pulse generation
   L62-8 (CG5B) - L62-15 (E)	Power switch off All doors closed Key not in cabin Door outside handle assembly (lock sensor) touched	Pulse generation

   TEXT IN ILLUSTRATION
   
   

   *a	Component with harness connected (Certification ECU (Smart Key ECU Assembly))

NG → See step   6 

OK: Go to next step 

1. Replace the No. 1 indoor electrical key antenna assembly (for front floor). Refer to REMOVAL .

NEXT: Go to next step 

1. Clear the DTCs. Refer to DTC CHECK / CLEAR .
2. Recheck for DTCs.

   OK

   DTC B27A5 is not output.

NG → See step   6 

OK → END (NO. 1 INDOOR ELECTRICAL KEY ANTENNA ASSEMBLY WAS DEFECTIVE)