B27A5

THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Entry Function): B27A5: Open in Front Floor Electrical Key Oscillator Circuit
B27A5 - Open in Front Floor Electrical Key Oscillator Circuit

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and sends it to the indoor electrical key oscillator (for front floor). To detect the key inside the cabin, the indoor electrical key oscillator (for front floor) creates a detection area in the cabin.

DTC B27A5 is detected by the certification ECU (smart key ECU assembly) when an open circuit occurs between the certification ECU (smart key ECU assembly) and indoor electrical key oscillator (for front floor) terminals (between CLG5 and CLG3, or CG5B and CLGB).





WIRING DIAGRAM





INSPECTION PROCEDURE

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 How To Proceed With Troubleshooting. 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 indoor electrical key oscillator (for front floor).

OK:

Connectors are properly connected.

NG -- CONNECT CONNECTORS PROPERLY
OK -- Continue to next step.

2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - INDOOR ELECTRICAL KEY OSCILLATOR)

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

(b) Disconnect the indoor electrical key oscillator (for front floor) connector.





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

Standard Resistance:





Text in Illustration

Text in Illustration:

NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.

3. INSPECT CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (INDOOR ELECTRICAL KEY OSCILLATOR SIGNAL OUTPUT)

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





(b) Measure the resistance and check for pulses according to the value(s) in the table below.

Standard Resistance:





Standard:





Text in Illustration

Text in Illustration:

NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal
OK -- Continue to next step.

4. REPLACE INDOOR ELECTRICAL KEY OSCILLATOR (for Front Floor)

(a) Replace the indoor electrical key oscillator (for front floor) Removal.

NEXT -- Continue to next step.

5. CHECK DTC OUTPUT

(a) Clear the DTCs Smart Key System (for Entry Function).

(b) Recheck for DTCs.

OK:

DTC B27A5 is not output.

NG -- REPLACE CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) Removal

OK -- END (INDOOR ELECTRICAL KEY OSCILLATOR WAS DEFECTIVE)