Theft Deterrent / Keyless Entry

Open in Outside Luggage Compartment Electrical Key Antenna Circuit (B27A8)

~3min read
DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and sends it to the outside electrical key oscillator (for rear side). To detect the key near the driver door, the outside electrical key oscillator (for rear side) creates a detection area towards the area approximately 1.0 m (3.28 ft.) from the back door.

DTC B27A8 is detected by the certification ECU (smart key ECU assembly) when an open circuit occurs between the certification ECU (smart key ECU assembly) and outside electrical key oscillator (for rear side) terminals (between CLG8 and CLG5, or CG8B and CLGB).

DTC No.

DTC Detection Condition

Trouble Area

B27A8

Open circuit detected between the certification ECU (smart key ECU assembly and outside electrical key oscillator (for rear side) terminals (between CLG8 and CLG5, or CG8B and CLGB).

  • Outside electrical key oscillator (for rear side)
  • Certification ECU (smart key ECU assembly)
  • Wire harness or connector
WIRING DIAGRAM
CAUTION / NOTICE / HINT

NOTICE:

The smart key system (for entry function) uses a multiplex communication system (LIN communication system) and CAN communication system. Inspect the communication function by following How to Proceed with Troubleshooting (See page ). Troubleshoot the smart key system (for entry
function) after confirming that the communication system is functioning properly.

PROCEDURE
  1. CHECK CONNECTOR CONNECTION CONDITION

(a) Turn the engine switch off.

(b) Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and the outside electrical key oscillator (for rear side).

OK:

Connectors are properly connected.


NG

CONNECT CONNECTORS PROPERLY

OK
  1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - OUTSIDE ELECTRICAL KEY OSCILLATOR)

(a) Disconnect the certification ECU (smart key ECU assembly) connector.

(b) Disconnect the outside electrical key oscillator (for rear side) connector.

(c) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

D26-19 (CLG8) - L17-1 (CLG5)

Always

Below 1 Ω

D26-20 (CG8B) - L17-2 (CLGB)

Always

Below 1 Ω

D26-19 (CLG8) - Body ground

Always

10 kΩ or higher

D26-20 (CG8B) - Body ground

Always

10 kΩ or higher

L17-1 (CLG5) - Body ground

Always

10 kΩ or higher

L17-2 (CLGB) - Body ground

Always

10 kΩ or higher

Text in Illustration

*1

Front view of wire harness connector

(to Certification ECU (Smart Key ECU Assembly))

*2

Front view of wire harness connector

(to Outside Electrical Key Oscillator (for Rear Side))


NG

REPAIR OR REPLACE HARNESS OR CONNECTOR

OK
  1. INSPECT OUTSIDE ELECTRICAL KEY OSCILLATOR

(a) Measure the resistance according to the value(s) in the table below.

Standard Resistance:

Tester Connection

Condition

Specified Condition

L17-1 (CLG5) - L17-2 (CLGB)

Always

Below 1 Ω

Text in Illustration

*1

Component without harness connected

(Outside Electrical Key Oscillator (for Rear Side))


NG

REPLACE OUTSIDE ELECTRICAL KEY OSCILLATOR

OK
  1. REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Replace the certification ECU (smart key ECU assembly) (See page ).


NEXT
  1. CHECK DTC OUTPUT

(a) Clear the DTCs (See page ).


(b) Recheck for DTCs.

OK:

DTC B27A8 is not output.


OK

END (CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) WAS DEFECTIVE)


NG

REPLACE OUTSIDE ELECTRICAL KEY OSCILLATOR

Test yourself

A quick Toyota Venza quiz: every answer comes with an explanation and a link to the manual page.