DTC U0016 – Medium Speed CAN Communication Bus Signal Error

What Does DTC U0016 Mean?

DTC U0016 indicates that the vehicle has detected an abnormal signal on the Medium-Speed Controller Area Network (MS-CAN). This means one or more control modules are receiving invalid or corrupted communication messages. The exact definition may vary by manufacturer.

Severity

High. Communication signal errors can affect multiple vehicle systems and may cause intermittent or complete module communication failures.

Can You Drive with U0016?

Yes, the vehicle is usually drivable, but some electronic features may not function correctly. The fault should be diagnosed and repaired promptly.

Symptoms

• Check Engine or communication warning light ON.
• Multiple U-codes stored.
• Intermittent loss of communication between modules.
• Warning messages in the instrument cluster.
• Electrical accessories operating unpredictably.

Common Causes

• Damaged CAN High or CAN Low wiring.
• Poor electrical connections or corroded terminals.
• Electrical interference on the CAN network.
• Faulty control module transmitting invalid data.
• Low battery voltage or charging system faults.

How to Diagnose U0016

1. Scan all control modules and record every communication DTC.
2. Check battery voltage and charging system output.
3. Inspect CAN wiring and connectors for damage.
4. Measure CAN bus resistance and voltage according to the factory service manual.
5. Disconnect suspected modules one at a time if communication remains unstable.
6. Repair the fault, clear all DTCs, and verify normal network operation.

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

• U0013
• U0014
• U0015
• U0017

Frequently Asked Questions

Can electrical interference cause U0016?

Yes. Excessive electrical noise or wiring damage can corrupt CAN signals and trigger this code.

Can one faulty module affect the entire CAN network?

Yes. A malfunctioning module may transmit invalid messages and disrupt communication with other modules.

Is U0016 the same on every vehicle?

No. The exact definition and diagnostic procedure vary between manufacturers. Always consult the factory service information for the specific vehicle.