AutoCodes – Generic – U1793

U1793 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 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 1,032

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

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?

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 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 U1793 code?

Need more information on how to fix the U1793 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1793 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

U1793 Buick — 14V Power Module Lost Communication With Hybrid/EV Powertrain Control Module On Powertrain Expansion Communication Bus
U1793 Cadillac — 14V Power Module Lost Communication With Hybrid/EV Powertrain Control Module On Powertrain Expansion Communication Bus
U1793 Chevrolet — 14V Power Module Lost Communication With Hybrid/EV Powertrain Control Module On Powertrain Expansion Communication Bus
U1793 GMC — 14V Power Module Lost Communication With Hybrid/EV Powertrain Control Module On Powertrain Expansion Communication 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 U1793 Code

What does the OBDII code U1793 mean?

The U1793 code 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 a U1793 code?

Symptoms may include warning lights on the dashboard, limited or no hybrid/EV functionality, reduced vehicle performance, or failure to charge the battery properly.

What causes the U1793 code to appear?

Common causes include damaged or corroded wiring, faulty connectors, a malfunctioning 14V Power Module, a defective Hybrid/EV Powertrain Control Module, or a software issue.

Can a U1793 code cause drivability issues?

Yes, it can lead to reduced performance, limited hybrid/EV functionality, or a failure in certain electrical systems.

How do you diagnose a U1793 code?

Diagnosis typically involves scanning for related codes, inspecting wiring and connectors on the communication bus, and testing the 14V Power Module and Hybrid/EV Powertrain Control Module for proper operation.

Can a U1793 code clear itself?

No, the code is unlikely to clear itself and will typically require diagnosis and repair to resolve the underlying issue.

Is the U1793 code specific to certain vehicles?

Yes, it is generally found in hybrid or electric vehicles equipped with a 14V Power Module and a Hybrid/EV Powertrain Control Module.

How can you fix a U1793 code?

Repairs may include fixing or replacing damaged wiring, cleaning or replacing faulty connectors, updating module software, or replacing the defective module.

Can a software update fix a U1793 code?

In some cases, a software update for the Powertrain Control Module or related systems can resolve communication issues.

Is it safe to drive with a U1793 code?

Driving with this code may lead to reduced hybrid/EV performance or other electrical issues, so itâ€™s best to address the problem promptly to avoid further complications.