AutoCodes – Buick – U1726 Buick

U1726 Buick Code - Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Low Beam Control Module

Quick Answer

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. Common causes include Faulty Right Headlamp Low Beam Control Module, Right Headlamp Low Beam Control Module harness is open or shorted, Right Headlamp Low Beam 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: U1726 Buick indicates Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Low Beam Control Module.
Common causes: Common causes include Faulty Right Headlamp Low Beam Control Module, Right Headlamp Low Beam Control Module harness is open or shorted, Right Headlamp Low Beam 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 483

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 Jun 04, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1726 Buick Description

The Local Interconnect Network (LIN) Bus consists of a single wire with a transmission rate of 10.417 Kbit/s. The serial data is transmitted over a LIN circuit between a master control module and other LIN devices within a particular subsystem. If serial data communication is lost between any of the LIN devices on the LIN bus network, the master control module will set a no communication code against the non-communicating LIN device. The Diagnostic Trouble Code (DTC) will set when a supervised periodic message to the Right Headlamp High Beam Control Module from the Right Headlamp Low Beam Control Module has not been received.

OBDII Code U1726 Buick - Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Low Beam Control Module - AutoCodes.com — U1726 Buick Code - Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Low Beam Control Module

What does this mean?

What are the Possible Causes of the DTC U1726 Buick?

Faulty Right Headlamp Low Beam Control Module
Right Headlamp Low Beam Control Module harness is open or shorted
Right Headlamp Low Beam Control Module circuit poor electrical connection
Faulty Right Headlamp High Beam Control Module

How to Fix the DTC U1726 Buick?

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 U1726 Buick 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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Need Help with the 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 U1726 Buick Code

What does the OBDII code U1726 mean for a Buick?

Code U1726 indicates a communication failure between the Right Headlamp High Beam Control Module and the Right Headlamp Low Beam Control Module.

What are common symptoms of the U1726 code?

Symptoms may include malfunctioning high or low beam headlights, warning lights on the dashboard, or inconsistent headlight operation.

What causes the U1726 code in a Buick?

Common causes include faulty wiring or connectors, a malfunctioning control module, or network communication errors within the vehicleâ€™s electrical system.

How can I diagnose the U1726 code?

Start by inspecting the wiring and connectors between the two modules, check for corrosion or damage, and use a diagnostic tool to confirm communication errors.

Can the U1726 code affect other vehicle systems?

While primarily related to the headlight system, communication issues can sometimes indicate broader electrical or network problems in the vehicle.

How do I fix the U1726 code on my Buick?

Repairs may involve replacing damaged wiring, connectors, or one of the affected control modules. A professional diagnosis is recommended for accurate troubleshooting.

Is it safe to drive with the U1726 code active?

While the vehicle is generally drivable, impaired headlight function can reduce visibility and compromise safety, especially at night.

How much does it cost to repair the U1726 code?

Repair costs vary depending on the issue but may range from $100 to $500 for wiring repairs or module replacement.

Can a software update fix the U1726 code?

In some cases, software updates to the vehicleâ€™s control modules may resolve communication errors, but hardware issues will require physical repairs.

What tools are needed to troubleshoot the U1726 code?

A diagnostic scanner capable of reading manufacturer-specific codes and electrical tools like a multimeter are useful for troubleshooting this code.