AutoCodes – Generic – U184B

U184B 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 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 1,247

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 Aug 09, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U184B 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 - Lost Communication with Remote Heater and Air Conditioning Control Module on Low Speed CAN Bus - AutoCodes.com — U184B 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?

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?

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 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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Information for Specific Makes

U184B Buick — Lost Communication with Remote Heater and Air Conditioning Control Module on Low Speed CAN Bus
U184B Cadillac — Lost Communication with Remote Heater and Air Conditioning Control Module on Low Speed CAN Bus
U184B Chevrolet — Lost Communication with Remote Heater and Air Conditioning Control Module on Low Speed CAN Bus
U184B GMC — Lost Communication with Remote Heater and Air Conditioning Control Module on Low Speed CAN Bus

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 Code

1. What are the common symptoms of OBDII code U184B?

- Common symptoms include issues with the remote heater or air conditioning control module, failure of the heater or AC system to respond to commands, and potential loss of communication with the module.

2. What can cause the OBDII code U184B to appear?

- The code U184B usually indicates a communication problem between the vehicle's low-speed CAN bus and the remote heater and air conditioning control module. This can be due to a faulty module, wiring issues, or a problem with the CAN bus network.

3. How do you diagnose the cause of OBDII code U184B?

- Diagnosing the cause of U184B typically involves checking the wiring and connections between the control module and the CAN bus, testing the module for proper function, and using a scan tool to assess communication on the low-speed CAN bus.

4. What are some repair tips for resolving OBDII code U184B?

- Repair tips may include checking and repairing any damaged wiring, ensuring proper connections to the control module, replacing a faulty control module if necessary, and resetting the code using a scan tool after repairs are completed.

5. Can OBDII code U184B affect the vehicle's performance?

- While the code itself may not directly impact the vehicle's drivability, a malfunctioning remote heater or air conditioning control module can lead to discomfort for passengers and may affect overall climate control functionality.

6. Is it safe to continue driving with OBDII code U184B present?

- It is generally safe to drive the vehicle with code U184B, but it is recommended to address the underlying issue promptly to prevent potential issues with the heater or air conditioning system.

7. Can a DIY enthusiast fix OBDII code U184B at home?

- Depending on the cause of the code, DIY enthusiasts with automotive repair experience may be able to address U184B by checking connections, replacing the control module, or repairing wiring. However, complex electrical issues may require professional assistance.

8. How much does it typically cost to repair OBDII code U184B?

- The cost of repairing U184B can vary depending on the cause of the issue, the need for replacement parts, and whether professional labor is required. Costs may range from a simple DIY fix to more expensive repairs at a dealership or repair shop.

9. Will resetting the OBDII code U184B make it go away permanently?

- Resetting the code may temporarily clear it, but if the underlying issue causing U184B is not addressed, the code is likely to reappear. It is important to diagnose and repair the root cause to prevent ongoing issues.

10. How can I prevent OBDII code U184B from reoccurring in the future?

- To prevent code U184B from reoccurring, perform regular maintenance on the vehicle's heating and air conditioning system, address any wiring or connection issues promptly, and ensure proper functionality of the remote heater and AC control module.