Lost communication with the TCM (models with radar sensor/ stereo camera) (AWR6B45)

1. Scan tool power-up check

1) Connect the scan tool.

2) Power up the scan tool. Does the scan tool power up?

Yes

=>Go to TCM communication verification.

No

Go to Scan tool does not power up.

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 with DPD) Scan tool does not power up".

Refer to "51.Engine Control 1A.Troubleshooting(4JJ3 without DPD) Scan tool does not power up".

Refer to "51.Engine Control 1A.Troubleshooting(RZ4E-TC) Scan tool does not power up".

2. TCM communication verification

1) Check the communication status with the TCM using the scan tool. Is communication with the TCM established?

Yes

Go to Intermittent conditions of transfer case control system.

Refer to "206.Transmission, Transaxle 19D.Symptom(AWR6B45) Intermittent conditions of automatic transmission".

No

=>Go to Central gateway control unit communication verification.

3. Central gateway control unit communication verification

1) Verify communication with the central gateway control unit using the scan tool. Can communication with the central gateway control unit be established?

Yes

=>Go to Powertrain CAN communication circuit communication verification.

No

Go to Lost communication with the central gateway control unit.

Refer to "64.Body Control 10I.Troubleshooting(Central GateWay) lost communication with the central gateway control unit".

4. Powertrain CAN communication circuit communication verification

1) Verify that communication can be established with the following control modules using a scan tool. Can communication with all the control modules be established?

  • ECM
  • TCCM
  • Battery sensor
  • Information module
  • Rear differential lock control unit

Yes

=>Go to TCM harness connector inspection.

No

Go to Powertrain CAN communication circuit inspection.

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

5. TCM harness connector inspection

1) Turn OFF the ignition switch.

2) Inspect for poor connections at the TCM harness connector (E5 and E7). Is the connection status normal?

Refer to "LHD Automatic Transmission" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Automatic Transmission" in the ETM (wiring diagram). (Open using the ETM viewer.).

Yes

=>Go to Fuse inspection.

No

Repair the connections as necessary.

=>Go to Repair verification.

6. Fuse inspection

1) Inspect the following fuses for a blowout. Is the result normal?

  • TCM/DRM 5A fuse
  • DC DC HEV/TCMâ‹…DRM 15A fuse

Yes

=>Go to Inspection for open circuit in battery power supply circuit.

No

Replace the fuse. If the fuse blows out again, repair the short to ground in the circuits relating to that fuse.

=>Go to Repair verification.

7. Inspection for open circuit in battery power supply circuit

1) Turn OFF the ignition switch.

2) Disconnect the TCM harness connector (E5).

3) Connect a test lamp between the battery power supply circuit (pin 10 of E5) and the body ground.

Refer to "LHD Automatic Transmission" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Automatic Transmission" in the ETM (wiring diagram). (Open using the ETM viewer.).

4) Turn ON the ignition switch. Does the test lamp illuminate?

Yes

=>Go to Inspection for open circuit in ground circuit.

No

Repair the open circuit or high resistance in the ignition power supply circuit between the TCM/DRM 5A fuse and the TCM (pin 21 of E5).

=>Go to Repair verification.

8. Inspection for open circuit in ground circuit

1) Connect a test lamp between the battery power supply circuit and the ground circuit (pins 1 and 10 of E5).

Refer to "LHD Automatic Transmission" in the ETM (wiring diagram). (Open using the ETM viewer.).

Refer to "RHD Automatic Transmission" in the ETM (wiring diagram). (Open using the ETM viewer.).

2) Turn ON the ignition switch. Does the test lamp illuminate?

Yes

=>Go to TCM ground inspection.

No

Repair the open circuit or high resistance in the ground circuit between the TCM (pin 1 of E5) and the body ground.

=>Go to Repair verification.

9. TCM ground inspection

1) Inspect the TCM ground section for corrosion or improper installation. Is the result normal?

Yes

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

No

Repair the ground point as necessary.

=>Go to Repair verification.

10. Inspection for open circuit and short circuit in CAN circuit

1) Inspect for poor connections at the CAN circuit junction connector between the TCM (pins 1 and 2 of E7) and the DLC (pins 6 and 14 of C19). Is the connection status normal?

2) Inspect the CAN High circuit and CAN Low circuit between the TCM (pins 1 and 2 of E7) and the DLC (pins 6 and 14 of C19) for the following. Is the result normal?

  • Open circuit
  • Short together
  • High resistance

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.).

3) Are all of the results normal?

Yes

=>Go to TCM replacement.

No

Repair the circuit or connection as necessary.

=>Go to Repair verification.

11. TCM replacement

Note

  • Perform programming after replacing the TCM.

Refer to "5.Transmission, Transaxle 5Z.Transmission Electrical Control(AWR6B45) TCM removal".

Refer to "5.Transmission, Transaxle 5Z.Transmission Electrical Control(AWR6B45) TCM installation".

Refer to "5.Transmission, Transaxle 5Z.Transmission Electrical Control(AWR6B45) TCM setting".

Procedure completion

=>Go to Repair verification.

12. Repair verification

1) Turn OFF the ignition switch.

2) Reconnect the disconnected harness connectors.

3) Turn ON the ignition switch.

4) Check the communication status with the TCM using the scan tool. Is communication with the TCM established?

Yes

The system is normal.

No

=>Go to TCM harness connector inspection.