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 electrical key antenna and the door control receiver 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 electrical key antenna and the door control receiver. 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 main body ECU RH.)






WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

1. CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - DOOR CONTROL RECEIVER)





(a) Disconnect the E58 ECU connector.
(b) Disconnect the O18 receiver 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.
2. CHECK HARNESS AND CONNECTOR (DOOR CONTROL RECEIVER - ELECTRICAL KEY ANTENNA)





(a) Disconnect the O19 antenna connector.
(b) Measure the resistance according to the value(s) in the table below.
HINT: Perform the measurement with the O18 receiver connector disconnected.

Standard resistance:






NG -- REPAIR OR REPLACE HARNESS OR CONNECTOR
OK -- Continue to next step.
3. CHECK AND REPLACE DOOR CONTROL RECEIVER (RECONFIRM DTC)
(a) Replace the receiver.
(b) Clear the DTCs and repeat the procedure to recheck for DTCs .
OK:
DTC is not output.
OK -- END (RECEIVER IS DEFECTIVE)
NG -- Continue to next step.
4. CHECK AND REPLACE ELECTRICAL KEY ANTENNA (RECONFIRM DTC)
(a) Replace the antenna.
(b) Clear the DTCs and repeat the procedure to recheck for DTCs .
OK:
DTC is not output.
OK -- END (ANTENNA IS DEFECTIVE)
NG -- REPLACE CERTIFICATION ECU