AutoCodes – Generic – U1726

U1726 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 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 1,068

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

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?

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 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 U1726 code?

Need more information on how to fix the U1726 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1726 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1726 Buick — Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Low Beam Control Module
U1726 Cadillac — Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Low Beam Control Module
U1726 Chevrolet — Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Low Beam Control Module
U1726 GMC — Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Low Beam Control Module

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 Code

1. What are the common symptoms of OBDII code U1726?

The common symptoms of code U1726 include a malfunctioning right headlamp high beam, issues with the right headlamp low beam, and possible lighting system malfunctions.

2. What can cause OBDII code U1726 to be triggered?

Code U1726 is typically triggered when the right headlamp high beam control module loses communication with the right headlamp low beam control module. This can be due to a wiring issue, a faulty control module, or a poor electrical connection.

3. How can I diagnose the cause of OBDII code U1726?

Diagnosing code U1726 usually involves checking the wiring connections between the control modules, inspecting for any damaged wires or connectors, and testing the control modules themselves for proper function.

4. Can OBDII code U1726 be cleared/reset without repairing the issue?

While you can clear the code with an OBDII scanner, it is recommended to diagnose and repair the underlying issue causing code U1726 to prevent further lighting system problems.

5. Is it safe to continue driving with OBDII code U1726 present?

It is not recommended to drive with code U1726 present, as it can indicate a potential issue with the vehicle's lighting system that may affect visibility and safety while driving.

6. Are there any DIY repair tips for fixing OBDII code U1726?

DIY repair tips may include checking and tightening any loose wiring connections, inspecting for visible damage to wiring harnesses, and ensuring proper grounding of the control modules.

7. Can extreme weather conditions trigger OBDII code U1726?

Extreme weather conditions such as heavy rain, snow, or extreme temperatures can potentially affect the electrical connections and wiring associated with the lighting control modules, leading to code U1726.

8. How much does it typically cost to repair OBDII code U1726?

The cost of repairing code U1726 can vary depending on the underlying issue, but it may involve replacing control modules, repairing wiring, or addressing electrical connection problems, which can range from moderate to high costs.

9. Will replacing the right headlamp control modules fix OBDII code U1726?

Replacing the control modules may resolve code U1726 if the issue lies with a faulty module, but it is important to diagnose the root cause of the communication loss between the modules to ensure a proper repair.

10. Can a professional mechanic help diagnose and repair OBDII code U1726?

Yes, a professional mechanic with experience in automotive electrical systems can help diagnose the cause of code U1726 and perform the necessary repairs to resolve the issue effectively.