U0029

Vehicle Communication Bus B

Moderate severity

Generic fault on vehicle communication bus B. Used as a catch-all for unspecified problems on a secondary CAN/comfort segment.

Common causes

Intermittent wiring fault on bus B
One of the most commonly reported causes for this code — check this first.
high
Typical part cost: $90-770
Gateway module routing CAN messages incorrectly
Less common, but worth ruling out after the more likely causes.
low
Typical part cost: $90-770
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First things to check

1Confirm the code with a scan tool and check for additional related codes.
2Inspect the relevant sensors, wiring, and connectors for damage or corrosion.

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Related codes

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Frequently asked questions

What does U0029 mean?

U0029 means "Vehicle Communication Bus B". It is a generic OBD-II code that points to a fault in the network / communication.

What are the most common causes of U0029?

intermittent wiring fault on bus b; gateway module routing can messages incorrectly; can terminating resistor (120 ω) drifted out of spec — these are the most commonly reported causes. Verify with a proper diagnosis before replacing parts, or use the Wrenchify app for a vehicle-specific diagnosis.

Can I keep driving with this code?

The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical. Use the Wrenchify app for a full diagnosis specific to your vehicle.

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