Engine-Codes - Generic - U18B2

U18B2 - Lost Communication With Rear Audio Control Module On Ethernet Bus

Repair Importance Level: 3/3
Repair Difficulty Level: 3/3  What is this?
Table of contents

U18B2 Possible Causes

  • Faulty Rear Audio Control Module
  • Rear Audio Control Module harness is open or shorted
  • Rear Audio Control Module circuit poor electrical connection

How is the U18B2 code repair?

Start by checking the "Possible Causes" listed above. Visually inspect the related wiring harness and connectors. Check for damaged components and look for broken, bent, pushed out, or corroded connector's pins.

What is the cost to diagnose the U18B2 code

Labor: 1.0

The cost to diagnose the U18B2 code is 1.0 hour of labor. The auto repair's diagnosis time and labor rates vary by location, vehicle's make and model, and even your engine type. Most auto repair shops charge between $75 and $150 per hour.
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Possible Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)

U18B2 Meaning

At the core of the infotainment system is the Radio Ethernet Audio Video Bridging switch which communicates directly to each contributing Infotainment control module terminator. The Ethernet harness consists of twisted pair wires from point to point. Each control module on the Ethernet infotainment system sends/receives data at 100 Mbit/s to/from a specified port at the Radio. The Radio Ethernet will also be used to program USB software update files to the control modules connected to the Ethernet ports. The Diagnostic Trouble Code (DTC) will set a supervised periodic message that includes the transmitter device availability that has not been received.

More Information

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Information for specific makes

  • U18B2 BUICK Lost Communication With Rear Audio Control Module On Ethernet Bus
  • U18B2 CADILLAC Lost Communication With Rear Audio Control Module On Ethernet Bus
  • U18B2 CHEVROLET Lost Communication With Rear Audio Control Module On Ethernet Bus
  • U18B2 GMC Lost Communication With Rear Audio Control Module On Ethernet Bus

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