DTC U0100[00] (Flash Code 31）Lost Communication With ECM for Brake Signal (Headlight Automatic Leveling Control)

1. Headlight auto leveling system check

Refer to "65.Lighting Control 10J.Troubleshooting(Headlight Automatic Leveling Control) diagnostic system check-headlight auto leveling controls".

2. Headlight auto leveling control unit DTC check

1) Observe whether a DTC is set in the headlight auto leveling control unit on the scan tool. Is a DTC set in the headlight auto leveling control unit?

Yes

=>Go to ECM communication verification.

No

Go to Intermittent conditions of lighting control system.

Refer to "224.Lighting Control 37D.Symptom(Headlight Automatic Leveling Control) intermittent conditions of lighting control system".

3. ECM communication verification

1) Use the scan tool to communicate with the ECM to display the data. Can communication with the ECM be established?

Yes

=>Go to ECM DTC check.

No (Models with radar sensors/stereo cameras)

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) lost communication with the ECM (models with radar sensor/ stereo camera)".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) lost communication with the ECM (models with radar sensor/ stereo camera)".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) lost communication with the ECM (models with radar sensor/ stereo camera)".

No (Models without radar sensors and stereo cameras)

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) lost communication with the ECM (models without radar sensor and stereo camera)".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) lost communication with the ECM (models without radar sensor and stereo camera)".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) lost communication with the ECM (models without radar sensor and stereo camera)".

4. ECM DTC check

1) Observe whether a DTC is set in the ECM on the scan tool. Is a DTC set in the ECM?

Yes

Go to the applicable DTC diagnosis.

No (Models with radar sensors/stereo cameras)

=>Go to Powertrain CAN communication circuit inspection and Body CAN communication circuit inspection.

No (Models without radar sensors and stereo cameras)

=>Go to CAN communication system inspection.

5. Powertrain CAN communication circuit inspection and Body CAN communication circuit inspection

1) Perform Powertrain CAN communication circuit inspection and Body CAN communication circuit inspection.

Refer to "64.Body Control 10I.Troubleshooting(Central GateWay) powertrain CAN communication circuit inspection".

Refer to "64.Body Control 10I.Troubleshooting(Central GateWay) body CAN communication circuit inspection".

Procedure completion

=>Go to Current DTC check.

6. CAN communication system inspection

1) Inspect the CAN communication system.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) scan tool does not communicate with CAN device (models without radar sensor and stereo camera)".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) scan tool does not communicate with CAN device (models without radar sensor and stereo camera)".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) scan tool does not communicate with CAN device (models without radar sensor and stereo camera)".

Procedure completion

=>Go to Current DTC check.

7. Current DTC check

1) Connect the scan tool.

2) Turn OFF the ignition switch.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool. Is a DTC set?

Yes

=>Go to ECM replacement.

No

=>Go to Repair verification.

8. ECM replacement

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) ECM removal".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) ECM installation".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 with DPD) ECM setting".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) ECM removal".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) ECM installation".

Refer to "1.Engine 1Z.Engine Electrical Control(4JJ3 without DPD) ECM setting".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM removal".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM installation".

Refer to "1.Engine 1Z.Engine Electrical Control(RZ4E-TC) ECM setting".

Procedure completion

=>Go to Repair verification.

9. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch.

3) Turn ON the ignition switch.

4) Observe the DTC information with a scan tool.