AutoCodes – Cadillac – U1727 Cadillac

U1727 Cadillac Code - Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Leveling Actuator

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 Leveling Actuator, Right Headlamp Leveling Actuator harness is open or shorted, Right Headlamp Leveling Actuator 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: U1727 Cadillac indicates Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Leveling Actuator.
Common causes: Common causes include Faulty Right Headlamp Leveling Actuator, Right Headlamp Leveling Actuator harness is open or shorted, Right Headlamp Leveling Actuator 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 446

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 U1727 Cadillac 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 Leveling Actuator has not been received.

OBDII Code U1727 Cadillac - Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Leveling Actuator - AutoCodes.com — U1727 Cadillac Code - Right Headlamp High Beam Control Module Lost Communication With Right Headlamp Leveling Actuator

What does this mean?

What are the Possible Causes of the DTC U1727 Cadillac?

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

How to Fix the DTC U1727 Cadillac?

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 U1727 Cadillac 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 U1727 Cadillac Code

1. What does the OBDII code U1727 mean on a Cadillac?

The U1727 code indicates a loss of communication between the right headlamp high beam control module and the right headlamp leveling actuator.

2. What are common symptoms of the U1727 code?

Symptoms may include the right headlamp high beam not functioning, improper headlamp leveling, or a warning light or message on the dashboard.

3. What causes the U1727 code on a Cadillac?

The code can be caused by a faulty headlamp leveling actuator, damaged wiring or connectors, a malfunctioning control module, or communication network issues.

4. Can I still drive my Cadillac with the U1727 code?

Yes, but driving with this code may result in reduced visibility at night due to improper headlamp operation, which could be a safety concern.

5. How is the U1727 code diagnosed?

A technician will use a scan tool to check for communication errors in the network, inspect wiring and connectors, and test the functionality of the headlamp leveling actuator and control module.

6. How do I fix the U1727 code on my Cadillac?

Repairs may involve replacing a faulty leveling actuator, repairing damaged wiring or connectors, updating software, or replacing the control module.

7. Is the U1727 code specific to Cadillacs?

While the U1727 code may appear on other vehicles, its exact meaning and application are specific to Cadillac's headlamp control system.

8. Can a dead battery cause the U1727 code?

Yes, a weak or dead battery can cause communication errors in the vehicleâ€™s network, potentially triggering the U1727 code.

9. How much does it cost to repair a U1727 code?

The cost depends on the underlying issue, ranging from $100 for wiring repairs to $500 or more for component replacements like the leveling actuator or control module.

10. Will resetting the code fix the U1727 issue?

Resetting the code may clear the warning temporarily, but it wonâ€™t fix the underlying issue. Proper diagnosis and repair are necessary to resolve the problem.