B27A1

THEFT DETERRENT / KEYLESS ENTRY: SMART KEY SYSTEM (for Entry Function): B27A1: Open in Driver Side Electrical Antenna Circuit
B27A1 - Open in Driver Side Electrical Antenna Circuit

DESCRIPTION

The certification ECU (smart key ECU assembly) generates a request signal and transmits the signal to the front door outside handle assembly LH (for driver door) [electrical key antenna] at intervals of 0.25 seconds. For the front door outside handle assembly LH (for driver door) [electrical key antenna] to detect when the electrical key transmitter sub-assembly is brought close to the vehicle, a signal requesting a response from the electrical key transmitter sub-assembly is transmitted within approximately 1 m (3.28 ft.) of the driver door at intervals of 0.25 seconds. DTC B27A1 is stored by the certification ECU (smart key ECU assembly) when an open circuit is detected between the certification ECU (smart key ECU assembly) and front door outside handle assembly LH (for driver door) [electrical key antenna] (between terminals CLG1 and ANT1, or terminals CG1B and ANT2).





* *: Only output while a malfunction is present.

Vehicle Condition and Fail-safe Operation when Malfunction Detected





Related Data List and Active Test





WIRING DIAGRAM





INSPECTION PROCEDURE

NOTICE:
* The smart key system (for Entry Function) uses a multiplex communication system (LIN communication system) and the 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 systems are functioning properly.
* When using the Techstream with the power switch off to troubleshoot:
Connect the Techstream to the DLC3 and turn a courtesy light switch on and off at 1.5-second intervals until communication between the Techstream and vehicle begins.
* Before replacing the certification ECU (smart key ECU assembly), refer to the smart key system (for Entry Function) precaution Smart Key System (for Entry Function).
* After repair, confirm that no DTCs are output by performing the "DTC Output Confirmation Operation".
* The front door outside handle assembly LH (for driver door) has an antenna coil between ANT1 and ANT2 terminals.

PROCEDURE

1. CHECK CONNECTOR CONNECTION

(a) Turn the power switch off.

(b) Check that the connectors are properly connected to the certification ECU (smart key ECU assembly) and front door outside handle assembly LH (for driver door).

OK:

Connectors are properly connected.

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

2. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH)

(a) Disconnect the I86 certification ECU (smart key ECU assembly) connector.

(b) Disconnect the W1 front door outside handle assembly LH (for driver door) connector.

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

Standard Resistance:





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

3. CHECK CERTIFICATION ECU (SMART KEY ECU ASSEMBLY) (OUTPUT TO DRIVER SIDE ELECTRICAL KEY ANTENNA)

(a) Connect the I86 certification ECU (smart key ECU assembly) connector.





Text in Illustration





(b) Connect the W1 front door outside handle assembly LH (for driver door) connector.

(c) Using an oscilloscope, check the waveform.

OK:





*1: For details about the areas that are inside the entry function detection area, refer to Operation Check Operation Check.

*2: For details about the areas that are outside the entry function detection area, refer to Operation Check Operation Check.

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

4. REPLACE FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH (FOR DRIVER DOOR)

(a) Temporarily replace the front door outside handle assembly LH (for driver door) with a new or known good one Disassembly.

NEXT -- Continue to next step.

5. CLEAR DTC

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

NEXT -- Continue to next step.

6. CHECK FOR DTC

(a) Check for DTCs Smart Key System (for Entry Function).

OK:

DTC B27A1 is not output.

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

OK -- END (FRONT DOOR OUTSIDE HANDLE ASSEMBLY LH (FOR DRIVER DOOR) WAS DEFECTIVE)