DTC U0140[00] Lost Communication With BCM (Wireless Access Module (Mid-version/Lo-version [Except Passive Entry and Start System]))

1. Wireless access module system check

Refer to "71.Security and Locks Control 10S.Troubleshooting(Wireless Access Module (Mid-version/Lo-version [Except Passive Entry and Start System])) Diagnostic system check-Wireless Access Module (Mid-version/Lo-version [Except Passive Entry and Start System])".

2. Wireless access module DTC check

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

Yes

=>Go to BCM communication verification.

No

Go to Intermittent conditions of wireless access module.

Refer to "229.Security and Locks Control 42D.Symptom intermittent conditions of wireless access module".

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)

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)

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 whether a DTC is set in the BCM on the scan tool. Is a DTC set in the BCM?

Yes

Go to the applicable DTC diagnosis.

No (Models with radar sensors/stereo cameras)

=>Go to Body CAN communication circuit inspection.

No (Models without radar sensors and stereo cameras)

=>Go to Inspection for open circuit and short circuit in CAN communication circuit.

5. Body CAN communication circuit inspection

1) Perform Body 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. Inspection for open circuit and short circuit in CAN communication circuit

1) Disconnect the BCM harness connector (B18).

2) Inspect the CAN Low circuit and CAN High circuit between the BCM (pins 4 and 3 of B18) and the wireless access module (pins 5 and 12 of B13) for the following. Is the result normal?

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

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

Yes

=>Go to CAN communication circuit voltage check.

No

Repair the circuit as necessary.

=>Go to Repair verification.

7. CAN communication circuit voltage check

1) Turn OFF the ignition switch.

2) Connect the BCM harness connector (B18).

3) Turn ON the ignition switch.

4) Measure the voltage between the CAN Low circuit of the wireless access module (pin 12 of B13) and the body ground with a DMM. Is the voltage within the specified range?

5) Measure the voltage between the CAN High circuit of the wireless access module (pin 5 of B13) and the body ground with a DMM. Is the voltage within the specified range?

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

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

Value: 1.5 to 3.5 V

6) Are all of the voltages within the specified range?

Yes

=>Go to Repair verification.

No

=>Go to BCM harness connector inspection.

8. BCM harness connector inspection

1) Inspect for poor connections at the BCM harness connector (pins 4 and 3 of B18). Is the connection status normal?

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

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

Yes

=>Go to Wireless access module harness connector inspection.

No

Repair the connections as necessary.

=>Go to Repair verification.

9. Wireless access module harness connector inspection

1) Inspect for poor connections at the wireless access module harness connector (pins 5 and 12 of B13). Is the connection status normal?

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

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

Yes

=>Go to BCM replacement.

No

Repair the connections as necessary.

=>Go to Repair verification.

10. BCM replacement

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control BCM removal".

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control BCM installation".

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control BCM setting".

Procedure completion

=>Go to Current DTC check.

11. Current DTC check

1) Turn OFF the ignition switch.

2) Close all the doors.

3) Lock and unlock the doors using the keyless entry function 5 times or more.

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

Yes

=>Go to Wireless access module replacement.

No

=>Go to Repair verification.

12. Wireless access module replacement

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control wireless access module removal".

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control wireless access module installation".

Refer to "9.Body, Cab, Accessories 9Z.Body, Cab, Accessories Electrical Control wireless access module setting (without passive entry and start system)".

Procedure completion

=>Go to Repair verification.

13. Repair verification

1) Clear the DTC with a scan tool.

2) Turn OFF the ignition switch.

3) Close all the doors.

4) Lock and unlock the doors using the keyless entry function 5 times or more.

5) Observe the DTC information with a scan tool.