DTC U0129[00] Lost Communication With Brake System (Stereo Camera)

1. Stereo camera system check

Refer to "75.Driver Assistance System 10W.Troubleshooting(Stereo Camera) diagnostic system check-stereo camera".

2. Current DTC check

1) Connect the scan tool.

2) Turn ON the ignition switch.

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

Yes

=>Go to EHCU communication verification.

No

Go to Intermittent conditions of stereo camera.

Refer to "233.Driver Assistance System 46D.Symptom(Stereo Camera) intermittent conditions of stereo camera".

3. EHCU communication verification

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

Yes

=>Go to EHCU DTC check.

No

Go to Lost communication with the EHCU.

Refer to "54.Brake Control 4A.Troubleshooting(ABS/ESC) lost communication with the EHCU (models with radar sensor/ stereo camera)".

4. EHCU DTC check

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

Yes

Go to the applicable DTC diagnosis.

No

=>Go to Chassis CAN communication circuit inspection.

5. Chassis CAN communication circuit inspection

1) Inspect the CAN Low circuit and CAN High circuit between the stereo camera (pins 7 and 8 of L17) and the EHCU (pins 14 and 26 of C13) for the following. Is the result normal?

  • Open circuit or high resistance
  • Short together between circuits
  • Short to battery or short to ignition power supply circuit
  • Short to ground

Refer to "LHD Controller Area Network (Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to EHCU harness connector inspection.

No

Repair the circuit as necessary.

=>Go to Repair verification.

6. EHCU harness connector inspection

1) Inspect for poor connections at the EHCU harness connector (pins 14 and 26 of C13). Is the connection status normal?

Refer to "LHD Controller Area Network (Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Stereo camera harness connector inspection.

No

Repair the connections as necessary.

=>Go to Repair verification.

7. Stereo camera harness connector inspection

1) Inspect for poor connections at the stereo camera harness connector (pins 7 and 8 of L17). Is the connection status normal?

Refer to "LHD Controller Area Network (Central Gateway C/U)" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 with DPD))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Controller Area Network (Central Gateway C/U (4JJ3 without DPD, RZ4E))" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

Replace the EHCU.

Note

  • Perform programming after replacing the EHCU.

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".

=>Go to Current DTC follow-up check.

No

Repair the connections as necessary.

=>Go to Repair verification.

8. Current DTC follow-up check

1) Securely connect the disconnected harness connectors.

2) Clear the DTC with a scan tool.

3) Turn OFF the ignition switch for 30 seconds or more.

4) Turn ON the ignition switch.

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

Yes

=>Go to Stereo camera replacement.

No

=>Go to Repair verification.

9. Stereo camera replacement

Note

  • Perform programming and learning after replacing the stereo camera.

Refer to "9.Body, Cab, Accessories 9E.Instrumentation, Driver Info. stereo camera removal".

Refer to "9.Body, Cab, Accessories 9E.Instrumentation, Driver Info. stereo camera installation".

Refer to "9.Body, Cab, Accessories 9E.Instrumentation, Driver Info. stereo camera setting".

Refer to "9.Body, Cab, Accessories 9E.Instrumentation, Driver Info. stereo camera writing".

Procedure completion

=>Go to Repair verification.

10. Repair verification

1) Securely connect the disconnected harness connectors.

2) Clear the DTC with a scan tool.

3) Turn OFF the ignition switch for 30 seconds or more.

4) Turn ON the ignition switch.

5) Observe the DTC information with a scan tool.