DTC Troubleshooting: U0029-00 (CAN Gateway) (2021 2022 2023 2024 2025)

DTC U0029-00  : CAN Gateway F-CAN ch A Bus Off

NOTE:  Before you troubleshoot, review the general troubleshooting information .

DTC (CAN GATEWAY)

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, and wait 6 seconds.

   -5. Check for DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off

   Is DTC U0029-00 indicated?

   YES 

   The failure is duplicated. Go to step 2.

   NO 

   Intermittent failure, the system is OK at this time. If the on-board snapshot of this DTC is recorded, try to reproduce the failure under the same conditions with the on-board snapshot .

2. Shorted unit check (PCM)

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

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

   -3. Disconnect the following connector.

   PCM connector A (50P)

   -4. Turn the vehicle to the ON mode.

   -5. Clear the DTC with the HDS.

   -6. Turn the vehicle to the OFF (LOCK) mode.

   -7. Turn the vehicle to the ON mode, and wait 6 seconds.

   -8. Check for DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off

   Is DTC U0029-00 indicated?

   YES 

   Go to step 3.

   NO 

   Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good PCM , then recheck. If DTC U0029-00 goes away and the PCM was substituted, replace the original PCM .

3. Shorted unit check (TCM)

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

   -2. Disconnect the following connector.

   TCM connector A (23P)

   -3. Turn the vehicle to the ON mode.

   -4. Clear the DTC with the HDS.

   -5. Turn the vehicle to the OFF (LOCK) mode.

   -6. Turn the vehicle to the ON mode, and wait 6 seconds.

   -7. Check for DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off

   Is DTC U0029-00 indicated?

   YES 

   Go to step 4.

   NO 

   Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good TCM , then recheck. If DTC U0029-00 goes away and the TCM was substituted, replace the original TCM .

4. Shorted unit check (VSA modulator-control unit)

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

   -2. Disconnect the following connector.

   VSA modulator-control unit 46P connector

   -3. Turn the vehicle to the ON mode.

   -4. Clear the DTC with the HDS.

   -5. Turn the vehicle to the OFF (LOCK) mode.

   -6. Turn the vehicle to the ON mode, and wait 6 seconds.

   -7. Check for DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off

   Is DTC U0029-00 indicated?

   YES 

   Go to step 5.

   NO 

   Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or replace the VSA modulator-control unit .

5. Shorted unit check (EPS control unit)

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

   -2. Disconnect the following connector.

   EPS control unit connector B (6P)

   -3. Turn the vehicle to the ON mode.

   -4. Clear the DTC with the HDS.

   -5. Turn the vehicle to the OFF (LOCK) mode.

   -6. Turn the vehicle to the ON mode, and wait 6 seconds.

   -7. Check for DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off

   Is DTC U0029-00 indicated?

   YES 

   Go to step 6.

   NO 

   Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or replace the EPS control unit .

6. Shorted unit check (engine mount control unit)

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

   -2. Disconnect the following connector.

   Engine mount control unit 16P connector

   -3. Turn the vehicle to the ON mode.

   -4. Clear the DTC with the HDS.

   -5. Turn the vehicle to the OFF (LOCK) mode.

   -6. Turn the vehicle to the ON mode, and wait 6 seconds.

   -7. Check for DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off

   Is DTC U0029-00 indicated?

   YES 

   Go to step 7.

   NO 

   Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good engine mount control unit , then recheck. If DTC U0029-00 goes away and the engine mount control unit was substituted, replace the original engine mount control unit .

7. Shorted unit check (SBW shifter control module)

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

   -2. Disconnect the following connector.

   SBW shifter control module 20P connector

   -3. Turn the vehicle to the ON mode.

   -4. Clear the DTC with the HDS.

   -5. Turn the vehicle to the OFF (LOCK) mode.

   -6. Turn the vehicle to the ON mode, and wait 6 seconds.

   -7. Check for DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off

   Is DTC U0029-00 indicated?

   YES 

   Go to step 8.

   NO 

   Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good SBW shifter control module , then recheck. If DTC U0029-00 goes away and the SBW shifter control module was substituted, replace the original SBW shifter control module .

8. Shorted unit check (electric brake booster)

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

   -2. Disconnect the following connector.

   Electric brake booster 26P connector

   NOTE:  Before disconnecting the electric brake booster connector, turn the vehicle to the OFF (LOCK) mode with the driver's door opened, and wait 3 minutes. Do not close the driver's door.

   -3. Turn the vehicle to the ON mode.

   -4. Clear the DTC with the HDS.

   -5. Turn the vehicle to the OFF (LOCK) mode.

   -6. Turn the vehicle to the ON mode, and wait 6 seconds.

   -7. Check for DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off

   Is DTC U0029-00 indicated?

   YES 

   Go to step 9.

   NO 

   Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or replace the electric brake booster .

9. Shorted unit check (ANC/active sound control unit)

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

   -2. Disconnect the following connector.

   ANC/active sound control unit 20P connector

   -3. Turn the vehicle to the ON mode.

   -4. Clear the DTC with the HDS.

   -5. Turn the vehicle to the OFF (LOCK) mode.

   -6. Turn the vehicle to the ON mode, and wait 6 seconds.

   -7. Check for DTCs with the HDS.

   DTC Description	DTC
   U0029-00 CAN Gateway F-CAN ch A Bus Off

   Is DTC U0029-00 indicated?

   YES 

   Go to step 10.

   NO 

   Substitute a known-good ANC/active sound control unit , then recheck. If DTC U0029-00 goes away and the ANC/active sound control unit was substituted, replace the original ANC/active sound control unit .

10. Shorted unit check (steering angle sensor)

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

    -2. Disconnect the following connector.

    Steering angle sensor 4P connector

    -3. Turn the vehicle to the ON mode.

    -4. Clear the DTC with the HDS.

    -5. Turn the vehicle to the OFF (LOCK) mode.

    -6. Turn the vehicle to the ON mode, and wait 6 seconds.

    -7. Check for DTCs with the HDS.

    DTC Description	DTC
    U0029-00 CAN Gateway F-CAN ch A Bus Off

    Is DTC U0029-00 indicated?

    YES 

    Go to step 11.

    NO 

    Substitute a known-good steering angle sensor , then recheck. If DTC U0029-00 goes away and the steering angle sensor was substituted, replace the original steering angle sensor .

11. Shorted unit check (SRS unit)

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

    -2. Disconnect the following connector.

    SRS unit connector A (39P)

    NOTE:  Before disconnecting the SRS unit connector, do the 12 volt battery terminal disconnection procedure and wait for at least 3 minutes.

    -3. Do the 12 volt battery terminal reconnection procedure .

    -4. Turn the vehicle to the ON mode.

    -5. Clear the DTC with the HDS.

    -6. Turn the vehicle to the OFF (LOCK) mode.

    -7. Turn the vehicle to the ON mode, and wait 6 seconds.

    -8. Check for DTCs with the HDS.

    DTC Description	DTC
    U0029-00 CAN Gateway F-CAN ch A Bus Off

    Is DTC U0029-00 indicated?

    1. YES 

       • Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good body control module , then recheck. If DTC U0029-00 goes away and the body control module was substituted, replace the original body control module .
       • If the original body control module is OK, go to step 12.

       NO 

       Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good SRS unit , then recheck. If DTC U0029-00 goes away and the SRS unit was substituted, replace the original SRS unit .

12. Shorted wire check (F-CAN A_H line)

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

    -2. Disconnect the following connectors.

    Body control module connector B (36P)

    CAN gateway 16P connector

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

    Test condition	Vehicle OFF (LOCK) mode
    	PCM connector A (50P): disconnected
    	TCM connector A (23P): disconnected
    	VSA modulator-control unit 46P connector: disconnected
    	EPS control unit connector B (6P): disconnected
    	Engine mount control unit 16P connector: disconnected
    	SBW shifter control module 20P connector: disconnected
    	Electric brake booster 26P connector: disconnected
    	ANC/active sound control unit 20P connector: disconnected
    	Steering angle sensor 4P connector: disconnected
    	SRS unit connector A (39P): disconnected
    	Body control module connector B (36P): disconnected
    	CAN gateway 16P connector: disconnected
    Test point 1	CAN gateway 16P connector (female terminals) No. 3:
    Test point 2	Body ground

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

    Is there 1 MΩ or more?

    YES 

    Go to step 13.

    NO 

    Repair a short in the F-CAN A_H wire between the CAN gateway and the connected units.

13. Shorted wire check (F-CAN A_L line)

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

    Test condition	Vehicle OFF (LOCK) mode
    	PCM connector A (50P): disconnected
    	TCM connector A (23P): disconnected
    	VSA modulator-control unit 46P connector: disconnected
    	EPS control unit connector B (6P): disconnected
    	Engine mount control unit 16P connector: disconnected
    	SBW shifter control module 20P connector: disconnected
    	Electric brake booster 26P connector: disconnected
    	ANC/active sound control unit 20P connector: disconnected
    	Steering angle sensor 4P connector: disconnected
    	SRS unit connector A (39P): disconnected
    	Body control module connector B (36P): disconnected
    	CAN gateway 16P connector: disconnected
    Test point 1	CAN gateway 16P connector (female terminals) No. 11:

    Test point 2

    Body ground

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

    Is there 1 MΩ or more?

    YES 

    Go to step 14.

    NO 

    Repair a short in the F-CAN A_L wire between the CAN gateway and the connected units.

14. Shorted wire check (F-CAN A_H line to F-CAN A_L line)

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

    Test condition	Vehicle OFF (LOCK) mode
    	PCM connector A (50P): disconnected
    	TCM connector A (23P): disconnected
    	VSA modulator-control unit 46P connector: disconnected
    	EPS control unit connector B (6P): disconnected
    	Engine mount control unit 16P connector: disconnected
    	SBW shifter control module 20P connector: disconnected
    	Electric brake booster 26P connector: disconnected
    	ANC/active sound control unit 20P connector: disconnected
    	Steering angle sensor 4P connector: disconnected
    	SRS unit connector A (39P): disconnected
    	Body control module connector B (36P): disconnected
    	CAN gateway 16P connector: disconnected
    Test point 1	CAN gateway 16P connector (female terminals) No. 3:
    Test point 2	CAN gateway 16P connector (female terminals) No. 11:

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

    Is there 1 MΩ or more?

    YES 

    Check for any authorized service information related to the DTCs or symptoms you are troubleshooting, or substitute a known-good CAN gateway , then recheck. If DTC U0029-00 goes away and the CAN gateway was substituted, replace the original CAN gateway .

    NO 

    Repair a short in the F-CAN A_H wire to the F-CAN A_L wire between CAN gateway terminals No. 3 and No. 11.