AutoCodes – Generic – U0186

U0186 Code - Lost Communication With Audio Amplifier 'A'

Quick Answer

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Common causes include Faulty Audio Amplifier 'A', Audio Amplifier 'A' harness is open or shorted, Audio Amplifier 'A' circuit poor electrical connection. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means: U0186 indicates Lost Communication With Audio Amplifier 'A'.
Common causes: Common causes include Faulty Audio Amplifier 'A', Audio Amplifier 'A' harness is open or shorted, Audio Amplifier 'A' circuit poor electrical connection.
Severity: High - diagnose this code as soon as possible.
Can I drive?: Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

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Code Popularity 11,432

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Apr 02, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
Comments
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Code U0186 Description

A Controller Area Network (CAN) is a vehicle bus standard designed to interconnect automotive devices without a host computer. Operating information and commands are exchanged among the devices. The devices have programmed information about what messages are needed to be exchanged on the serial data circuits. CAN bus uses two dedicated wires for communication. The wires are called CAN high and CAN low. When the CAN bus is in idle mode, both lines carry 2.5V. When data bits are being transmitted, the CAN high line goes to 3.75V, and the CAN low drops to 1.25V, thereby generating a 2.5V differential between the lines. Since communication relies on a voltage differential between the two bus lines, the CAN bus is NOT sensitive to inductive spikes, electrical fields, or other noise. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Audio Amplifier 'A' has not been received.

OBDII Code U0186 - Lost Communication With Audio Amplifier 'A' - AutoCodes.com — U0186 Code - Lost Communication With Audio Amplifier 'A'

What does this mean?

What are the Possible Causes of the DTC U0186?

Faulty Audio Amplifier 'A'
Audio Amplifier 'A' harness is open or shorted
Audio Amplifier 'A' circuit poor electrical connection

How to Fix the DTC U0186?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0186 code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the U0186 code?

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Information for Specific Makes

U0186 Buick — Lost Communication With Speaker Amplifier Module
U0186 Cadillac — Lost Communication With Speaker Amplifier Module
U0186 Chevrolet — Lost Communication With Speaker Amplifier Module
U0186 Chrysler — Lost Communication With Audio Amplifier 'A'
U0186 Dodge — Lost Communication With Audio Amplifier 'A'
U0186 GMC — Lost Communication With Speaker Amplifier Module
U0186 Jeep — Lost Communication With Audio Amplifier 'A'
U0186 RAM — Lost Communication With Audio Amplifier 'A'

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.