AutoCodes – Buick – U1793 Buick

U1793 Buick Code - 14V Power Module Lost Communication With Hybrid/EV Powertrain Control Module On Powertrain Expansion Communication Bus

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 Hybrid/EV Powertrain Control Module, Hybrid/EV Powertrain Control Module harness is open or shorted, Hybrid/EV Powertrain 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: U1793 Buick indicates 14V Power Module Lost Communication With Hybrid/EV Powertrain Control Module On Powertrain Expansion Communication Bus.
Common causes: Common causes include Faulty Hybrid/EV Powertrain Control Module, Hybrid/EV Powertrain Control Module harness is open or shorted, Hybrid/EV Powertrain 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 600

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

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Table of contents Created and updated by William Orellana on Jun 07, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1793 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 14V Power Module from the Hybrid/EV Powertrain Control Module has not been received.

OBDII Code U1793 Buick - 14V Power Module Lost Communication With Hybrid/EV Powertrain Control Module On Powertrain Expansion Communication Bus - AutoCodes.com — U1793 Buick Code - 14V Power Module Lost Communication With Hybrid/EV Powertrain Control Module On Powertrain Expansion Communication Bus

What does this mean?

What are the Possible Causes of the DTC U1793 Buick?

Faulty Hybrid/EV Powertrain Control Module
Hybrid/EV Powertrain Control Module harness is open or shorted
Hybrid/EV Powertrain Control Module circuit poor electrical connection
Faulty 14V Power Module

How to Fix the DTC U1793 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 U1793 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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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 U1793 Buick Code

What does OBDII code U1793 mean for a Buick?

Code U1793 indicates that the 14V Power Module has lost communication with the Hybrid/EV Powertrain Control Module on the Powertrain Expansion Communication Bus.

What are the common symptoms of code U1793 in a Buick?

Symptoms may include warning lights on the dashboard, reduced vehicle performance, or failure of hybrid/EV systems to operate correctly.

What causes code U1793 to appear in a Buick?

Common causes include faulty wiring or connectors, a malfunctioning 14V Power Module, issues with the Hybrid/EV Powertrain Control Module, or network communication faults.

Can code U1793 affect vehicle drivability?

Yes, depending on the severity, it can lead to reduced performance, loss of hybrid functionality, or even prevent the vehicle from starting.

How can I diagnose code U1793 in my Buick?

Begin by inspecting wiring and connectors for damage or corrosion, followed by checking for power and ground at the affected modules, and using a scan tool to monitor network communication.

Is code U1793 related to a specific Buick model?

This code can appear in Buick models equipped with hybrid or electric powertrain systems that utilize the 14V Power Module.

What repair steps can resolve code U1793 in a Buick?

Repairs may include replacing damaged wiring or connectors, reprogramming or replacing the affected modules, or addressing network communication issues.

Do I need specialized tools to fix code U1793 in a Buick?

Yes, a professional-grade scan tool and multimeter are typically required to diagnose and repair communication issues effectively.

Can I clear code U1793 without fixing the underlying issue?

Clearing the code without addressing the root cause will likely result in the code returning and continued vehicle performance issues.

Is code U1793 covered under warranty for a Buick?

It depends on your vehicleâ€™s warranty coverage and age. Communication-related issues in hybrid systems may be covered under powertrain or emissions warranties.