DTC U0017 – Medium Speed CAN Communication Bus Timeout

What Does DTC U0017 Mean?

DTC U0017 indicates that one or more control modules failed to receive expected messages over the Medium-Speed Controller Area Network (MS-CAN) within the required time. This timeout condition is typically caused by communication interruptions, wiring faults, or a malfunctioning control module. The exact definition may vary by manufacturer.

Severity

High. A communication timeout can prevent vehicle modules from exchanging critical information, affecting multiple electronic systems.

Can You Drive with U0017?

In most cases, the vehicle can still be driven, but some electronic features may be disabled or operate intermittently. Repair is recommended as soon as possible.

Symptoms

• Check Engine or communication warning light ON.
• Multiple U-codes stored.
• Loss of communication with one or more modules.
• Warning messages displayed on the instrument cluster.
• Intermittent electrical system operation.

Common Causes

• Open or shorted CAN High or CAN Low wiring.
• Loose, damaged, or corroded connectors.
• Faulty control module.
• Low battery voltage or charging system problems.
• Excessive network traffic or communication errors.

How to Diagnose U0017

1. Scan every control module and record all communication DTCs.
2. Check battery voltage and charging system output.
3. Inspect CAN wiring and connectors.
4. Measure CAN bus resistance and voltage according to the factory service manual.
5. Disconnect suspected modules if the network remains unstable.
6. Repair the fault, clear the codes, and verify proper communication.

Typical CAN Network Layout

         PCM
          │
          ▼
      CAN Bus
          │
          ▼
         BCM
          │
          ▼
         ABS
          │
          ▼
         TCM
          │
          ▼
 Instrument Cluster

Estimated Repair Cost

• CAN wiring repair: $80–300
• Connector replacement: $30–150
• Battery or charging system repair: $50–250
• Control module replacement: $300–1,000

Related DTCs

• U0014
• U0015
• U0016
• U0018

Frequently Asked Questions

Can a weak battery cause U0017?

Yes. Low system voltage can interrupt CAN communication and contribute to timeout errors.

Can one faulty module cause U0017?

Yes. A malfunctioning control module can stop responding on the network, causing communication timeouts.

Is U0017 the same on every vehicle?

No. The exact description and diagnostic procedure vary by manufacturer. Always consult the factory service information for your specific vehicle.