DTC U129E (A/T System (Without CAN Gateway)) (2016 2017 2018 2019 2020)

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 

   Go to the symptom troubleshooting for keyless access indicator does not go off or does not come on - Refer to: Keyless Access System Symptom Troubleshooting - Keyless access indicator does not go off or does not come on

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 System (Keyless Access Control Unit, Electric Steering Lock, and TPMS Control Unit) Input Test (2017 2018 2019 2020), or Keyless Access System (Keyless Access Control Unit, Electric Steering Lock, and TPMS Control Unit) Input Test (2016)
   Test point 2	TCM 58P connector No. 34

   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 System (Keyless Access Control Unit, Electric Steering Lock, and TPMS Control Unit) Input Test (2017 2018 2019 2020), or Keyless Access System (Keyless Access Control Unit, Electric Steering Lock, and TPMS Control Unit) Input Test (2016)
   Test point 2	TCM 58P connector No. 47

   Is there continuity?

   YES 

   The F-CAN A_L wire is OK. Substitute a known-good keyless access/TPMS control unit , then recheck. If this DTC goes away and the keyless access/TPMS control unit was substituted, replace the original 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.