AutoCodes – GMC – U184B 2017 GMC Sierra

U184B 2017 GMC Sierra Code - Lost Communication with Remote Heater and Air Conditioning Control Module on Low Speed CAN Bus

Quick Answer

The serial data circuit is the means by which the devices in the vehicle communicate with each other. Common causes include Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module, Heating, Ventilation, and Air Conditioning Control Module harness is open or shorted, Heating, Ventilation, and Air Conditioning Control 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: U184B 2017 GMC Sierra indicates Lost Communication with Remote Heater and Air Conditioning Control Module on Low Speed CAN Bus.
Common causes: Common causes include Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module, Heating, Ventilation, and Air Conditioning Control Module harness is open or shorted, Heating, Ventilation, and Air Conditioning Control 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 207

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Jul 24, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U184B 2017 GMC Sierra Description

The serial data circuit is the means by which the devices in the vehicle communicate with each other. Once the scan tool is connected to the serial data circuit through the Data Link Connector (DLC), the scan tool can be used to monitor each device for diagnostic purposes and to check for Diagnostic Trouble Codes (DTC). When the vehicle is ON, each device communicating on the serial data circuit sends a state of health message to ensure that the device is operating properly. When a device stops communicating on the serial data circuit, for example, if the device loses power or ground, the state of health message it normally sends on the serial data circuit disappears. Other devices on the serial data circuit, which expect to receive that state of health message, detect its absence; those devices in turn set a DTC associated with the loss of state of health of the non-communicating device. A loss of serial data communications DTC does not represent a failure of the devices that contain the stored DTC.

OBDII Code U184B 2017 GMC Sierra - Lost Communication with Remote Heater and Air Conditioning Control Module on Low Speed CAN Bus - AutoCodes.com — U184B 2017 GMC Sierra Code - Lost Communication with Remote Heater and Air Conditioning Control Module on Low Speed CAN Bus

What does this mean?

What are the Possible Causes of the DTC U184B 2017 GMC Sierra?

Faulty Heating, Ventilation, and Air Conditioning (HVAC) Control Module
Heating, Ventilation, and Air Conditioning Control Module harness is open or shorted
Heating, Ventilation, and Air Conditioning Control Module circuit poor electrical connection

How to Fix the DTC U184B 2017 GMC Sierra?

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 U184B 2017 GMC Sierra 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.

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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 U184B 2017 GMC Sierra Code

1. What does the OBDII code U184B mean for a 2017 GMC Sierra?

The U184B code indicates a loss of communication with the Remote Heater and Air Conditioning Control Module on the low-speed CAN bus.

2. What are the common symptoms of the U184B code on a GMC Sierra?

Common symptoms include malfunctioning HVAC controls, no response from the climate system, or the HVAC system operating in default mode.

3. What causes the U184B code to appear?

Potential causes include a faulty Remote Heater and Air Conditioning Control Module, wiring issues in the low-speed CAN bus, or a software issue in the control module.

4. Can a bad HVAC control module trigger the U184B code?

Yes, a malfunctioning or failed HVAC control module can result in a loss of communication and trigger the U184B code.

5. How can I diagnose the U184B code on my 2017 GMC Sierra?

Diagnosis typically involves scanning for additional codes, inspecting wiring and connections on the low-speed CAN bus, and testing the functionality of the Remote HVAC module.

6. Is the U184B code related to a blown fuse?

Yes, a blown fuse in the circuit powering the HVAC control module can disrupt communication and cause the code to appear.

7. Can software updates fix the U184B code?

In some cases, a software update for the HVAC module or other related control modules can resolve communication issues and clear the code.

8. What tools are needed to repair the U184B code?

Youâ€™ll need a diagnostic scanner capable of reading GM-specific codes, a multimeter to check wiring, and potentially a wiring diagram for the low-speed CAN bus system.

9. Is it safe to drive with the U184B code active?

Yes, the vehicle is generally safe to drive, but the HVAC system may not function properly until the issue is resolved.

10. How much does it cost to fix the U184B code on a 2017 GMC Sierra?

Repair costs vary depending on the issue but can range from $100 for minor wiring repairs to $600 or more if the HVAC control module needs replacement.