AutoCodes – GMC – U0186 GMC

U0186 GMC Code - Lost Communication With Speaker Amplifier Module

Quick Answer

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Speaker Amplifier Module, Speaker Amplifier Module harness is open or shorted, Speaker Amplifier Module 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 GMC indicates Lost Communication With Speaker Amplifier Module.
Common causes: Common causes include Faulty Speaker Amplifier Module, Speaker Amplifier Module harness is open or shorted, Speaker Amplifier Module 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 1,303

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
FAQs
Comments
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Code U0186 GMC Description

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver module as an availability indication of the transmitter module. The supervision time-out period is 250 ms. Each message contains the identification number of the transmitter module. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Speaker Amplifier Module has not been received.

OBDII Code U0186 GMC - Lost Communication With Speaker Amplifier Module - AutoCodes.com — U0186 GMC Code - Lost Communication With Speaker Amplifier Module

What does this mean?

What are the Possible Causes of the DTC U0186 GMC?

Faulty Speaker Amplifier Module
Speaker Amplifier Module harness is open or shorted
Speaker Amplifier Module circuit poor electrical connection

How to Fix the DTC U0186 GMC?

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 GMC 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 GMC code?

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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.

Frequently Asked Questions about U0186 GMC Code

1. What are the common symptoms of OBDII code U0186 GMC (Lost Communication With Speaker Amplifier Module)?

- Common symptoms include loss of sound from the vehicle's speakers, distorted audio, or complete silence from the audio system.

2. What are some possible causes of OBDII code U0186 GMC?

- The code U0186 is typically triggered by a faulty speaker amplifier module, damaged wiring or connectors, or a communication breakdown between the module and the vehicle's computer.

3. How can I diagnose the issue related to code U0186 GMC?

- Diagnose the issue by checking the wiring and connectors related to the speaker amplifier module, testing the module itself for functionality, and using a diagnostic scan tool to identify communication errors.

4. Can a DIY enthusiast repair OBDII code U0186 GMC?

- Repairing code U0186 may require technical expertise due to the complexity of the audio system and communication modules involved. It is recommended to consult a professional mechanic for accurate diagnosis and repair.

5. Is it safe to drive with OBDII code U0186 GMC present?

- While the vehicle may still be operable with code U0186, it is not recommended to ignore the issue as it may affect the overall functionality of the audio system and potentially other vehicle systems.

6. How much does it typically cost to repair OBDII code U0186 GMC?

- The cost of repairing code U0186 can vary depending on the root cause of the issue, the extent of the damage, and the labor rates of the repair shop. It is advisable to get multiple quotes for an accurate estimate.

7. Can resetting the OBDII code U0186 resolve the issue temporarily?

- Resetting the code may temporarily clear the fault from the vehicle's system, but if the underlying issue is not addressed, the code is likely to reappear.

8. Are there any preventive measures to avoid OBDII code U0186 GMC in the future?

- Regularly inspecting and maintaining the vehicle's audio system, ensuring proper wiring connections, and addressing any audio system issues promptly can help prevent the recurrence of code U0186.

9. Will OBDII code U0186 GMC cause any other problems in the vehicle?

- While code U0186 is primarily related to the communication with the speaker amplifier module, unresolved issues with communication systems in the vehicle can potentially lead to other electrical problems over time.

10. How long does it typically take to repair OBDII code U0186 GMC?

- The repair time for code U0186 can vary depending on the complexity of the diagnosis and the availability of parts. In some cases, it may be resolved within a few hours, but more extensive repairs could take longer.