DTC : U0100, U0122 (2019 2020)

DTC U0100  : Power Control Unit Lost Communication with PCM

DTC U0122  : Power Control Unit Lost Communication with ABS/VSA Modulator-Control Unit

NOTE: 

• If you are troubleshooting multiple DTCs, be sure to follow the instructions in B-CAN System Diagnosis Test Mode A - Go to: Body Electrical Troubleshooting - B-CAN System Diagnosis Test Mode A - Initial Communication and DTC Checks .
• According to the detected DTC(s), check for the power circuit and the ground circuit of the control unit which cannot communicate with the keyless access/TPMS control unit.
• Refer to the DTC shown on the display, then inspect the connectors and terminals based on the instructions.

DTC (Power Control Unit)

1. 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
   U0029-00 CAN Gateway F-CAN ch A Bus Off
   U3000-49 CAN Gateway Internal Failure

   Is DTC U0029-00 and/or U3000-49 indicated?

   YES 

   Go to the troubleshooting for CAN gateway system Communication Systems DTC(s) (2019 2020 2021) .

   NO 

   Go to step 2.

2. 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 Connection Check

   Does the Keyless access/TPMS control unit detect the CAN gateway Bus channels A?

   Bus B is Not Available

   Go to step 3.

   Bus B is Available

   Go to step 4.

3. Open wire check (F-CAN A lines)

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

   - 2. Disconnect the following connectors.

   CAN gateway 16P connector Keyless access/TPMS control unit connector C (20P)

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

   Test condition	Vehicle OFF (LOCK) mode CAN gateway 16P connector: disconnected Keyless access/TPMS control unit connector C (20P): disconnected
   Test point 1	CAN gateway 16P connector (female terminals) No. 3: (1)
   Test point 2	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) .

   Test point 1	CAN gateway 16P connector (female terminals) No. 11: (1)
   Test point 2	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) .

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The F-CAN A_H and F-CAN A_L wires are OK. Replace the Keyless Access/TPMS Control Unit - Removal and Installation .

   NO 

   Repair an open in F-CAN A_H or F-CAN A_L wire.

4. F-CAN circuit communication check (Transmitting control unit)

   -1. Select the FUNCTION TEST in the CAN gateway with the HDS, then select the F-CAN Bus Connected Unit Check.

   F-CAN Connection Check

   According to the detected DTC on the following table, make sure that the transmitting control unit detects the CAN gateway Bus channel(s) normally.

   DTC	Transmitting control unit	Detected CAN gateway Bus channel(s) at normal
   U0100	PCM	A
   U0122	VSA modulator-control unit	A

   Is it detected normally?

   Detected normal

   Intermittent failure, the system is OK at this time. Check for poor connections or loose terminals at the transmitting control unit and the CAN gateway.

   U0100: PCM is Not Available for Bus A

   Go to step 5.

   U0122: VSA modulator-control unit is Not Available for Bus A

   Go to step 5.

5. Open wire check (F-CAN A lines)

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

   - 2. U0100: Jump the SCS line with the HDS, and wait more than 1 minute.

   SCS short

   - 3. According to the detected DTC on the following table, disconnect the transmitting control unit connector(s).

   DTC	Connector
   -	CAN gateway 16P connector
   U0100	PCM connector A (51P)
   U0122	VSA modulator-control unit 38P connector

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

   Test condition

   Vehicle OFF (LOCK) mode CAN gateway 16P connector: disconnected Transmitting control unit connector(s) for indicated DTCs: disconnected

   DTC	Circuit name	Receiving control unit		Transmitting control unit
   		Connector	Terminal	Connector	Terminal
   U0100	F-CAN A_H	CAN gateway 16P connector (female terminals) (1)	No. 3	PCM connector A (51P) - Go to: PCM Connector for Inputs and Outputs (6-Speed A/T),	No. 9
   	F-CAN A_L		No. 11		No. 10
   U0122	F-CAN A_H	CAN gateway 16P connector (female terminals) (1)	No. 3	VSA modulator-control unit 38P connector - Refer to: VSA Modulator-Control Unit Connector for Inputs and Outputs (2019 2020 2021) .	No. 6
   	F-CAN A_L		No. 11		No. 7

   Courtesy of HONDA, U.S.A., INC.

   Is there continuity?

   YES 

   The F-CAN A_H wire and the F-CAN A_L wire are OK. Refer to the DTC shown on the display, then replace the control unit based on the instructions (see table).

   DTC	Operation for transmitting control unit
   U0100	PCM - Refer to: PCM (6-Speed A/T) - Removal and Installation
   U0122	VSA modulator-control unit Removal and Installation .

   NO 

   Repair an open in F-CAN A_H or F-CAN A_L wire.