B1242

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

DESCRIPTION

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

This DTC is output when one of the following occurs: 1) short in RDA or RSSI ground between the certification ECU and the door control receiver, or 2) short in RDA or RSSI ground when RC0 (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.





WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

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

(a) Disconnect the L15 ECU connector.





(b) Disconnect the R37 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

(a) Disconnect the R37 receiver connector.





(b) Measure the resistance and voltage according to the value(s) in the table below.

Standard resistance:





Standard voltage:





NG -- REPLACE CERTIFICATION ECU
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 if the same DTC is not output Reading and Clearing Diagnostic Trouble Codes.

OK:

DTC B1242 is not output.

NG -- REPLACE CERTIFICATION ECU

OK -- END (DOOR CONTROL RECEIVER IS DEFECTIVE)