DTC U0146
DTC U0146 : Lost Communication With CAN Gateway
- Before you troubleshoot, review the General Troubleshooting Information .
- According to the detected DTC(s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the TCM.
| DTC Description | Confirmed DTC | Pending DTC | Freeze Frame |
|---|---|---|---|
| U0146 Lost Communication With CAN Gateway |
DTC (A/T)
- Problem verification
- 1. Turn the vehicle to the ON mode.
- 2. Clear the DTC with the HDS.
- 3. Check for Pending or Confirmed DTCs with the HDS.
DTC Description Confirmed DTC Pending DTC Freeze Frame U0146 Lost Communication With CAN Gateway Is DTC U0146 indicated?
YES
The failure is duplicated. Go to step 2.
NO
Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the CAN gateway and the TCM. If the freeze data/on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the freeze data/on-board snapshot.
- CAN gateway system DTC check
- 1. Turn the vehicle to the ON mode.
- 2. Check for CAN gateway system DTCs with the HDS.
DTC Description DTC Are any DTCs indicated?
YES
Go to the indicated DTC's troubleshooting in the CAN gateway system .
NO
Go to step 3.
- F-CAN circuit communication check
- 1. Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.
F-CAN Bus Connected Unit Check
Which result is indicated?
PCM (Bus A) is Not Available
Go to step 4.
PCM (Bus B) is Not Available
Go to step 6.
- Open wire check (F-CAN A_H line)
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connectors.
CAN gateway 16P connector TCM 58P connector - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode CAN gateway 16P connector: disconnected TCM 58P connector: disconnected Test point 1 CAN gateway 16P connector (female terminals) No. 3: Test point 2 TCM 58P connector No. 34 - Refer to: A/T Control System Connector for Inputs and Outputs (2016 2017 2018), or A/T Control System Connector for Inputs and Outputs (2019), or A/T Control System Connector for Inputs and Outputs (2020 2021) . Is there continuity?
YES
The F-CAN A_H wire is OK. Go to step 5.
NO
Repair an open in the F-CAN A_H wire between the CAN gateway and the TCM.
- Open wire check (F-CAN A_L line)
- 1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode CAN gateway 16P connector: disconnected TCM 58P connector: disconnected Test point 1 CAN gateway 16P connector (female terminals) No. 11: Test point 2 TCM 58P connector No. 47 - Refer to: A/T Control System Connector for Inputs and Outputs (2016 2017 2018), or A/T Control System Connector for Inputs and Outputs (2019), or A/T Control System Connector for Inputs and Outputs (2020 2021) . Is there continuity?
YES
The F-CAN A_L wire is OK. Check for poor connections or loose terminals at the CAN gateway and the TCM. If they are OK, replace the original TCM .
NO
Repair an open in the F-CAN A_L wire between the CAN gateway and the TCM.
- Open wire check (F-CAN B_H line)
- 1. Turn the vehicle to the OFF (LOCK) mode.
- 2. Disconnect the following connectors.
CAN gateway 16P connector TCM 58P connector - 3. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode CAN gateway 16P connector: disconnected TCM 58P connector: disconnected Test point 1 CAN gateway 16P connector (female terminals) No. 6: Test point 2 TCM 58P connector No. 7 - Refer to: A/T Control System Connector for Inputs and Outputs (2016 2017 2018), or A/T Control System Connector for Inputs and Outputs (2019), or A/T Control System Connector for Inputs and Outputs (2020 2021) . Is there continuity?
YES
The F-CAN B_H wire is OK. Go to step 7.
NO
Repair an open in the F-CAN B_H wire between the CAN gateway and the TCM.
- Open wire check (F-CAN B_L line)
- 1. Check for continuity between test points 1 and 2.
Test condition Vehicle OFF (LOCK) mode CAN gateway 16P connector: disconnected TCM 58P connector: disconnected Test point 1 CAN gateway 16P connector (female terminals) No. 14: Test point 2 TCM 58P connector No. 20 - Refer to: A/T Control System Connector for Inputs and Outputs (2016 2017 2018), or A/T Control System Connector for Inputs and Outputs (2019), or A/T Control System Connector for Inputs and Outputs (2020 2021) . Is there continuity?
YES
The F-CAN B_L wire is OK. Check for poor connections or loose terminals at the CAN gateway and the TCM. If they are OK, replace the original TCM .
NO
Repair an open in the F-CAN B_L wire between the CAN gateway and the TCM.