DTC U0140[87] Lost Communication With BCM (ABS/ESC)

1. Brake control system check

Refer to "54.Brake Control 4A.Troubleshooting(ABS/ESC) diagnostic System Check - Brake Controls".

2. Current DTC check

1) Connect the scan tool.

2) Start the engine.

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

Yes

=>Go to BCM communication verification.

No

Go to Intermittent conditions of brake.

Refer to "205.Brakes 18D.Symptom intermittent conditions of brake".

3. BCM communication verification

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

Yes

=>Go to BCM DTC check.

No (Models with radar sensors/stereo cameras)

Go to Lost communication with the BCM.

Refer to "64.Body Control 10I.Troubleshooting(BCM) lost communication with the BCM (models with radar sensor/ stereo camera)".

No (Models without radar sensors and stereo cameras)

Go to Lost communication with the BCM.

Refer to "64.Body Control 10I.Troubleshooting(BCM) lost communication with the BCM (models without radar sensor and stereo camera)".

4. BCM DTC check

1) Observe the BCM DTC information on the scan tool. Is a DTC set?

Yes

Go to the applicable DTC diagnosis.

No (Models with radar sensors/stereo cameras)

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

No (Models without radar sensors and stereo cameras)

=>Go to CAN communication circuit inspection.

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

1) Perform the Body CAN communication circuit inspection and Chassis CAN communication circuit inspection.

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

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

Procedure completion

=>Go to Current DTC follow-up check.

6. CAN communication circuit inspection

1) Perform Scan tool does not communicate with CAN device.

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 follow-up check.

7. Current DTC follow-up check

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch.

3) Start the engine.

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

Yes

=>Go to EHCU replacement.

No

=>Go to Repair verification.

8. EHCU replacement

Refer to "4.Brakes 4Z.Brake Electrical Control EHCU removal".

Refer to "4.Brakes 4Z.Brake Electrical Control EHCU installation".

Refer to "4.Brakes 4Z.Brake Electrical Control EHCU 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) Start the engine.

4) Observe the DTC information with a scan tool.