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U0028: Vehicle Communication Bus A

Severity
Low
NHTSA Reports
2
Vehicles Affected
2
System
Powertrain

What Does U0028 Mean?

U0028 is a diagnostic trouble code indicating: Vehicle Communication Bus A. This code relates to the network communication system. It has been reported in NHTSA complaints across 2 different vehicle models.

Common Causes

Real Owner Reports

From NHTSA complaint database — actual owner descriptions.

"I WAS TRAVELLING ON A FREEWAY ~70MPH IN LEFT HAND LANE. WITHOUT WARNING THE INSTRUMENT CLUSTER WENT BLACK AND THE ENGINE STOPPED. THE VEHICLE STARTED TO DECELERATE AND THERE WAS NO RESPONSE FROM THE THROTTLE PEDAL. AN ORANGE BOX APPEARED ON THE LEFT HAND SIDE OF THE SPEEDOMETER SAYING 'TRANSMISSI"

— Ford Taurus owner, 04/18/2019

"TL* THE CONTACT OWNS A 2014 CHEVROLET IMPALA. WHILE DRIVING APPROXIMATELY 30 TO 35 MPH, THE VEHICLE STALLED WITHOUT WARNING. THE CONTACT WAS ABLE TO MOVE ONTO A SIDE STREET AND RESTARTED THE ENGINE. THE CONTACT TOOK THE VEHICLE TO AN UNKNOWN DEALER WHERE SEVERAL FAILURES WERE LOCATED. THE DEALER STA"

— Chevrolet Impala owner, 08/21/2019

Source: NHTSA Complaints Database

Most Reported Vehicles for U0028

Based on NHTSA owner complaint data.

# Vehicle Reports
1 FORD TAURUS
2 CHEVROLET IMPALA

Frequently Asked Questions

What causes communication codes?
Usually a wiring issue, corroded connector, failed module, or dead battery. The CAN bus network connects all your car's computers.
Can a bad battery cause network codes?
Yes. Low voltage can cause communication failures between modules. Always check battery health first — it's the cheapest potential fix.

What To Do Next

Possible Fixes

  • 🔧 Have the code scanned with a professional-grade scanner to read freeze frame data
  • 🔧 Test the relevant sensor(s) with a multimeter before replacing
  • 🔧 Check battery voltage and ground connections; inspect CAN bus wiring
  • 🔧 If DIY repair isn't feasible, get a diagnostic from a trusted mechanic ($50-150)
  1. 1
    Find your vehicle above

    Click your make and model for real owner reports and common causes specific to your vehicle.

  2. 2
    Check for recalls

    Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.

  3. 3
    Get a professional diagnosis

    A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.

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