AutoCodes – Chevrolet – U1803 Chevrolet

U1803 Chevrolet Code - Lost Communication with Hybrid/EV Powertrain Control Module 2

Quick Answer

The serial data circuit is the means by which the devices in the vehicle communicate with each other. Common causes include Faulty Hybrid/EV Powertrain Control Module 2, Hybrid/EV Powertrain Control Module 2 harness is open or shorted, Hybrid/EV Powertrain Control Module 2 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: U1803 Chevrolet indicates Lost Communication with Hybrid/EV Powertrain Control Module 2.
Common causes: Common causes include Faulty Hybrid/EV Powertrain Control Module 2, Hybrid/EV Powertrain Control Module 2 harness is open or shorted, Hybrid/EV Powertrain Control Module 2 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 1,009

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 Jul 21, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1803 Chevrolet Description

The serial data circuit is the means by which the devices in the vehicle communicate with each other. Once the scan tool is connected to the serial data circuit through the Data Link Connector (DLC), the scan tool can be used to monitor each device for diagnostic purposes and to check for Diagnostic Trouble Codes (DTC). When the vehicle is ON, each device communicating on the serial data circuit sends a state of health message to ensure that the device is operating properly. When a device stops communicating on the serial data circuit, for example, if the device loses power or ground, the state of health message it normally sends on the serial data circuit disappears. Other devices on the serial data circuit, which expect to receive that state of health message, detect its absence; those devices in turn set a DTC associated with the loss of state of health of the non-communicating device. A loss of serial data communications DTC does not represent a failure of the devices that contain the stored DTC.

OBDII Code U1803 Chevrolet - Lost Communication with Hybrid/EV Powertrain Control Module 2 - AutoCodes.com — U1803 Chevrolet Code - Lost Communication with Hybrid/EV Powertrain Control Module 2

What does this mean?

What are the Possible Causes of the DTC U1803 Chevrolet?

Faulty Hybrid/EV Powertrain Control Module 2
Hybrid/EV Powertrain Control Module 2 harness is open or shorted
Hybrid/EV Powertrain Control Module 2 circuit poor electrical connection

How to Fix the DTC U1803 Chevrolet?

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 U1803 Chevrolet 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 U1803 Chevrolet code?

Need more information on how to fix the U1803 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U1803 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

U1803 2014 Chevrolet Silverado — Lost Communication with Hybrid/EV Powertrain Control Module 2
U1803 2015 Chevrolet Silverado — Lost Communication with Hybrid/EV Powertrain Control Module 2
U1803 2016 Chevrolet Silverado — Lost Communication with Hybrid/EV Powertrain Control Module 2
U1803 2017 Chevrolet Silverado — Lost Communication with Hybrid/EV Powertrain Control Module 2
U1803 2018 Chevrolet Silverado — Lost Communication with Hybrid/EV Powertrain Control Module 2

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 U1803 Chevrolet Code

What does the OBDII code U1803 mean for a Chevrolet vehicle?

The U1803 code indicates that there is a lost communication with Hybrid/EV Powertrain Control Module 2, which can affect the vehicle's hybrid or electric powertrain performance.

What symptoms might I experience if my vehicle has the U1803 code?

Common symptoms include warning lights on the dashboard, reduced engine power, erratic behavior of the hybrid system, and potential failure to start.

What are some potential causes of the U1803 code?

Possible causes include a faulty Hybrid/EV Powertrain Control Module 2, damaged wiring or connectors, issues with the communication network, or a malfunctioning battery management system.

How can I diagnose the U1803 code accurately?

Use an OBDII scanner to read the code, inspect the wiring and connectors related to the Hybrid/EV Powertrain Control Module 2, and check for any other related codes that may provide more context to the issue.

What are some common repairs for the U1803 code?

Repairs may involve replacing the faulty Hybrid/EV Powertrain Control Module 2, repairing or replacing damaged wiring and connectors, or updating the vehicle's software if necessary.

Can I drive my Chevrolet if the U1803 code is present?

While it may be possible to drive the vehicle, itâ€™s not recommended as the hybrid system may not function properly, which can lead to reduced performance or safety issues.

How do I clear the U1803 code after repairs?

After addressing the underlying issue, you can use an OBDII scanner to clear the code, but ensure that the problem is fully resolved to prevent the code from returning.

Is the U1803 code serious, and should I seek professional help?

Yes, the U1803 code indicates a communication issue that can impact the vehicle's performance and safety. It is advisable to seek professional help to diagnose and repair the problem.

Will a battery issue trigger the U1803 code?

Yes, a weak or failing battery can affect the power supply to the Hybrid/EV Powertrain Control Module, potentially triggering the U1803 code.