B1242

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

DTC B1242 - Wireless Door Lock Tuner Circuit Malfunction

DESCRIPTION

The door control receiver receives signals from the transmitter and sends these signals to the main body ECU.

B1242:

WIRING DIAGRAM





INSPECTION PROCEDURE

PROCEDURE

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




(a) Disconnect the E63 main body ECU connector and the M13 door control receiver connector.
(b) 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 (+B, GND)




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





(b) Measure the voltage according to the value(s) in the table below.
Standard Voltage:






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

3. REPLACE DOOR CONTROL RECEIVER
(a) Reconnect the E63 main body ECU connector.
(b) Replace the door control receiver with a known good one Removal.
(c) Perform the registration procedure Registration.
HINT: If a known good door control receiver is available, connect it and check if the wireless door lock function is normal or DTCs are output. If the alternative receiver functions normally, replace the original door control receiver.

NEXT -- Continue to next step.

4. CONFIRM DTC
(a) Clear the DTCs Reading and Clearing Diagnostic Trouble Codes.
(b) Check if the same DTC is detected.
HINT: Reinstall the sensors, connectors, etc. and restore the previous vehicle conditions before rechecking for DTCs.

Result:






B -- REPLACE MAIN BODY ECU
A -- END (DOOR CONTROL RECEIVER)