AutoCodes – Generic – U184A

U184A Code - Lost Communication with Body 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 Body Control Module (BCM), Body Control Module harness is open or shorted, Body 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: U184A indicates Lost Communication with Body Control Module on Low Speed CAN Bus.
Common causes: Common causes include Faulty Body Control Module (BCM), Body Control Module harness is open or shorted, Body 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 1,713

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 U184A 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 U184A - Lost Communication with Body Control Module on Low Speed CAN Bus - AutoCodes.com — U184A Code - Lost Communication with Body Control Module on Low Speed CAN Bus

What does this mean?

What are the Possible Causes of the DTC U184A?

Faulty Body Control Module (BCM)
Body Control Module harness is open or shorted
Body Control Module circuit poor electrical connection

How to Fix the DTC U184A?

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 U184A 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 U184A code?

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Information for Specific Makes

U184A Buick — Lost Communication with Body Control Module on Low Speed CAN Bus
U184A Cadillac — Lost Communication with Body Control Module on Low Speed CAN Bus
U184A Chevrolet — Lost Communication with Body Control Module on Low Speed CAN Bus
U184A GMC — Lost Communication with Body 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 U184A Code

1. What are the common symptoms of OBDII code U184A - Lost Communication with Body Control Module on Low Speed CAN Bus?

- Common symptoms include non-functioning interior lights, power window issues, door lock problems, and overall electrical system malfunctions.

2. What are the possible causes of OBDII code U184A?

- The code U184A can be caused by a faulty body control module, damaged wiring or connectors in the CAN bus network, a software malfunction, or a low voltage condition.

3. How can I diagnose the OBDII code U184A?

- Diagnosis involves using a professional OBDII scanner to communicate with the vehicle's onboard computer system. This will help pinpoint the exact source of the communication failure.

4. How can I repair OBDII code U184A?

- Repairing the code may involve checking and repairing damaged wiring, replacing the body control module if necessary, updating software, or addressing any underlying electrical issues.

5. Can I still drive my vehicle with the U184A code present?

- It is not recommended to drive the vehicle with the U184A code present, as it can lead to further electrical system issues and potential safety hazards.

6. Will resetting the code make it go away permanently?

- Simply resetting the code may temporarily clear the warning light, but it will likely reappear if the underlying issue causing the communication failure is not resolved.

7. How much does it cost to repair OBDII code U184A?

- The cost of repair can vary depending on the specific cause of the issue and the labor rates in your area. It is recommended to consult with a professional mechanic for an accurate estimate.

8. Can a DIY enthusiast fix the U184A code at home?

- While some DIY enthusiasts may have the skills to diagnose and repair the issue causing the U184A code, it is often recommended to seek professional help due to the complexity of electrical systems.

9. Is the U184A code specific to a certain make or model of vehicle?

- The U184A code can appear on various makes and models of vehicles that utilize the Low Speed CAN Bus communication system for the body control module.

10. How can I prevent the U184A code from recurring in the future?

- Regular maintenance, checking and maintaining the integrity of wiring and connectors, and addressing any electrical issues promptly can help prevent the U184A code from recurring.