B1242

DOOR LOCK: WIRELESS DOOR LOCK CONTROL SYSTEM: B1242: Wireless Door Lock Tuner Circuit Malfunction
B1242 - Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

The door control receiver is used to receive electrical waves relating to the entry functions of the smart access system with push-button start (for Entry Function). The certification ECU (smart key ECU assembly) decodes the requested smart access system with push-button start (for Entry Function) operation by identifying a key code based on the electric waves received via the door control receiver. The door control receiver receives a signal from the door control transmitter and sends signals to the main body ECU (cowl side junction block LH) through the certification ECU (smart key ECU assembly). The certification ECU (smart key ECU assembly) then sends a command, according to the requested operation, to each ECU (ex. if door lock operation is requested, the certification ECU (smart key ECU assembly) sends a door lock command to the main body ECU).

This DTC is stored when one of the following occurs: 1) a short in RDA or RSSI to ground between the certification ECU (smart key ECU assembly) and the door control receiver, or 2) a short in RDA or RSSI to ground when RCO (5 V) output from the ECU is off.

NOTICE:
* When replacing or inspecting the door control receiver and wire harness, do not change the position or length of the wire harness. If the wire harness is too close to the door control receiver, entry and wireless function performance may be affected.
* Before performing the inspection, check that there are no problems related to the CAN communication system and LIN communication system.
* When using the Techstream with the engine switch off to troubleshoot: Connect the Techstream to the vehicle, and turn the front door courtesy light switch LH on and off at 1.5 second intervals until communication between the Techstream and vehicle begins.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

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

(a) Disconnect the E29 ECU connector.





(b) Disconnect the L21 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 CERTIFICATION ECU (SMART KEY ECU ASSEMBLY)

(a) Disconnect the L21 receiver connector.





(b) Reconnect the E29 ECU connector.

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

Standard Voltage:





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

3. REPLACE DOOR CONTROL RECEIVER

(a) Temporarily replace the door control receiver with a new one Removal.

NEXT -- Continue to next step.

4. CHECK FOR DTC

(a) Clear the DTC Reading and Clearing Diagnostic Trouble Codes.

(b) Recheck for DTC Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1242 is not output.

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

OK -- END (DOOR CONTROL RECEIVER IS DEFECTIVE)