DTC B1242: Wireless Door Lock Tuner Circuit Malfunction: Procedure
WARNING: This page is about a different car, the 2011 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.
- CHECK HARNESS AND CONNECTOR (CERTIFICATION ECU - TUNER)
- Disconnect the D39 ECU connector.
- Disconnect the L11 tuner connector.
- Measure the resistance according to the value(s) in the table below.
Resistance
Tester Connection Condition Specified Condition D39-39 (RSSI) - L11-5 (RSSI) Always Below 1 Ω D39-38 (RDA) - L11-3 (DATA) Always Below 1 Ω D39-29 (RC0) - L11-2 (+5) Always Below 1 Ω D39-39 (RSSI) - Body ground Always 10 kΩ or higher D39-38 (RDA) - Body ground Always 10 kΩ or higher D39-29 (RC0) - Body ground Always 10 kΩ or higher
NG → REPAIR OR REPLACE HARNESS OR CONNECTOR
OK: Go to next step
- INSPECT CERTIFICATION ECU
- Reconnect the D39 ECU connector.
- Measure the voltage according to the value(s) in the table below.
Voltage
Tester Connection Condition Specified Condition D39-39 (RSSI) - Body ground Engine switch OFF, all doors closed, the key is not in the action area. → the key in the action area. 0 to 6 V → Below 1 V D39-38 (RDA) - Body ground Engine switch OFF, all doors closed and transmitter switch not pressed 11 to 14 V pulse generation at regular intervals Engine switch OFF, all doors closed and transmitter switch pressed Pulse generation D39-29 (RC0) - Body ground Engine switch OFF, all doors closed and key switch OFF → ON Below 1 V → 4.6 to 5.4 V Result
Result Proceed to OK (When troubleshooting according to the DLC chart) A OK (When troubleshooting according to the PROBLEM SYMPTOMS TABLE) B NG C
B → PROCEED TO PROBLEM SYMPTOMS TABLE NEXT CIRCUIT INSPECTION SHOWN IN PROBLEM SYMPTOMS TABLE
C → REPLACE CERTIFICATION ECU
A: Go to next step
- REPLACE TUNER (RECONFIRM DTC)
- Replace the tuner.
- Clear the DTC and repeat the procedure to re-check it. Refer to DTC CHECK / CLEAR
.
OK
DTC is output.
NG → REPLACE CERTIFICATION ECU
OK → END (TUNER IS DEFECTIVE)