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All codes/U0012

U0012

Medium Speed CAN Communication Bus (-) Open

Moderate severity

The CAN-Low wire on the medium-speed comfort/body bus is open. Body modules such as door modules, climate control or seat modules lose communication, but powertrain functions usually stay alive.

The CAN-Low wire on the medium-speed comfort/body bus is open. Body modules such as door modules, climate control or seat modules lose communication, but powertrain functions usually stay alive.

Common causes

  • CAN-Low wire broken in body harness

    One of the most commonly reported causes for this code — check this first.

    high

    Typical part cost: $70-550

  • Loose body control module connector

    A plausible cause — test and verify before replacing parts.

    medium

    Typical part cost: $70-550

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First things to check

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

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Tools you may need

Already have a compatible scanner? Use it. If not, a Bluetooth OBD2 adapter can help you confirm engine codes and check supported live sensor data before replacing parts.

Illustration of a Bluetooth OBD2 adapter, not a product photo

Basic checks

Veepeak OBDCheck BLE

A Bluetooth LE adapter for reading standard engine codes and supported live data.

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Illustration of a Bluetooth OBD2 adapter, not a product photo

Regular diagnostics

vgate iCar Pro BLE 4.0

A Bluetooth LE adapter with an automatic sleep feature for routine code and sensor checks.

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Illustration of a Bluetooth OBD2 adapter, not a product photo

Another option

OBDLink CX

A Bluetooth LE adapter to consider when comparing supported vehicles and diagnostic apps.

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Illustrations shown, not product photos. Check vehicle, phone and app compatibility before buying. These adapters do not guarantee access to ABS, airbags or manufacturer-specific systems. Clearing a code does not repair the fault and can reset emissions readiness monitors.

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Related codes

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Frequently asked questions

What does U0012 mean?

U0012 means "Medium Speed CAN Communication Bus (-) Open". It is a generic OBD-II code that points to a fault in the network / communication.

What are the most common causes of U0012?

can-low wire broken in body harness; loose body control module connector; gateway module routing can messages incorrectly — 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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