Door Lock - Smart Key System

DOOR LOCK: SMART KEY SYSTEM: B1242: Wireless Door Lock Tuner Circuit Malfunction

DTC B1242 - Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

- The tuner and the Luggage Compartment tuner are used as antennas for the entry and wireless door lock functions of the smart key system.
- The certification ECU decodes the requested smart key system operation by identifying a key code based on electric waves received via the tuner and the Luggage Compartment tuner. The ECU then sends a command, according to the requested operation, to each ECU. (e.g. If door lock operation is requested, the ECU sends a door lock command to the body ECU.)





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK WIRE HARNESS (CERTIFICATION ECU - TUNER)





(a) Disconnect the D39 ECU connector.





(b) Disconnect the L11 tuner connector.
(c) Measure the resistance according to the value(s) in the table below.
Resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
2. INSPECT CERTIFICATION ECU





(a) Reconnect the D39 ECU connector.
(b) Measure the voltage according to the value(s) in the table below.
Voltage:






NG -- REPLACE CERTIFICATION ECU
OK -- Continue to next step.
3. CHECK WIRE HARNESS (TUNER - LUGGAGE COMPARTMENT TUNER)





(a) Disconnect the L21 tuner connector.





(b) Measure the resistance according to the value(s) in the table below.
Resistance:






Result:






B -- PROCEED TO NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C -- REPAIR OR REPLACE HARNESS OR CONNECTOR
A -- Continue to next step.
4. REPLACE TUNER (RECONFIRM DTC)
(a) Replace the tuner.
(b) Clear the DTC and repeat the procedure to re-check it Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC is output.
OK -- END (TUNER IS DEFECTIVE)
NG -- Continue to next step.
5. REPLACE LUGGAGE COMPARTMENT TUNER (RECONFIRM DTC)
(a) Replace the luggage compartment tuner.
(b) Clear the DTC and repeat the procedure to re-check it Reading and Clearing Diagnostic Trouble Codes.
OK:
DTC is not output.
OK -- END (LUGGAGE COMPARTMENT TUNER IS DEFECTIVE)
NG -- REPLACE CERTIFICATION ECU