Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
DTC U0029-00 (VSA Control Unit: Without ACC)
DTC U0029-00 : CAN Communication Failure (Bus OFF)
NOTE:
- This DTC is stored by communication failure between the F-CAN line and the VSA modulator-control unit. When DTC U0029-00 is indicated, the F-CAN line has already returned to normal. Check for loose terminals and poor connections at the connectors. If the connectors are OK, clear the DTC and follow this troubleshooting.
- Troubleshoot any PGM-FI system DTCs first .
- Before you troubleshoot, review the general troubleshooting information .
| DTC Description | DTC | Freeze Frame |
|---|---|---|
| U0029-00 CAN Communication Failure (Bus OFF) |
DTCs (VSA)
- Connector check (VSA modulator-control unit connector)
-1. Turn the vehicle to the OFF (LOCK) mode.
-2. Check for loose terminals and poor connections at the following connector.
VSA modulator-control unit 46P connector Is the connector OK?
YES
Go to step 2.
NO
Repair loose terminal or poor connection. Then clear the DTC by using the HDS and recheck DTC U0029-00. If DTC U0029-00 is not confirmed, troubleshooting is complete.
- VSA modulator-control unit communication check
-1. Turn the vehicle to the OFF (LOCK) mode, then start the engine.
-2. Check for communication between the VSA modulator-control unit and the HDS.
Is there communication between the VSA modulator-control unit and the HDS?
YES
Intermittent failure, the system is OK at this time. Refer to intermittent failures troubleshooting . 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.
NO
NO RELATED
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.