DTC U129E

DTC U129E  : Lost Communication with PCU

DTC (A/T)

1. Problem verification

   - 1. Turn the vehicle to the ON mode.

   - 2. Clear the DTC with the HDS.

   - 3. Turn the vehicle to the OFF (LOCK) mode.

   - 4. Turn the vehicle to the ON mode.

   - 5. Check for Pending or Confirmed DTCs with the HDS.

   DTC Description	Confirmed DTC	Pending DTC	Freeze Frame
   U129E Lost Communication with PCU

   Is DTC U129E indicated?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. Check for poor connections and loose terminals between the keyless access/TPMS control unit 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.

2. Keyless access system check

   - 1. Check for communication to the keyless access system with the HDS.

   Does the HDS communicate with the keyless access system?

   YES 

   Go to step 3.

   NO 

   Refer to: Symptom Troubleshooting Index for Viewer .

3. Open wire check (F-CAN A_H line)

   - 1. Turn the vehicle to the OFF (LOCK) mode.

   - 2. Disconnect the following connectors.

   Keyless access/TPMS control unit connector C (20P)

   TCM 58P connector

   - 3. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Keyless access/TPMS control unit connector C (20P): disconnected
   	TCM 58P connector: disconnected
   Test point 1	Keyless access/TPMS control unit connector C (20P) No. 2 - Refer to: Keyless Access/TPMS Control Unit Connector for Inputs and Outputs (2019 2020 2021) or Keyless Access/TPMS Control Unit Connector for Inputs and Outputs (2016 2017 2018) .
   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 4.

   NO 

   Repair an open in the F-CAN A_H wire between the keyless access/TPMS control unit and the TCM.

4. Open wire check (F-CAN A_L line)

   - 1. Check for continuity between test points 1 and 2.

   Test condition	Vehicle OFF (LOCK) mode
   	Keyless access/TPMS control unit connector C (20P): disconnected
   	TCM 58P connector: disconnected
   Test point 1	Keyless access/TPMS control unit connector C (20P) No. 12 - Refer to: Keyless Access/TPMS Control Unit Connector for Inputs and Outputs (2019 2020 2021) or Keyless Access/TPMS Control Unit Connector for Inputs and Outputs (2016 2017 2018) .
   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 any authorized service information related to the DTCs or symptoms you are troubleshooting or substitute a known-good keyless access/TPMS control unit .

   NO 

   Repair an open in the F-CAN A_L wire between the keyless access/TPMS control unit and the TCM.