AutoCodes – Chevrolet – U0020 Chevrolet

U0020 Chevrolet Code - Low Speed CAN Bus

Quick Answer

Devices connected to the General Motors Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include If other codes are present, diagnose other codes first, Faulty Control Module, Control Module harness is open or shorted. 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: U0020 Chevrolet indicates Low Speed CAN Bus.
Common causes: Common causes include If other codes are present, diagnose other codes first, Faulty Control Module, Control Module harness is open or shorted.
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 8,257

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 Jul 19, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code U0020 Chevrolet Description

Devices connected to the General Motors Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices. The devices have programmed information about what messages need to be exchanged on the serial data circuits. The messages are also supervised, and some periodic messages are used by the receiver device as an availability indication of the transmitter device. The Diagnostic Trouble Code (DTC) will be set when a supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U0020 Chevrolet - Low Speed CAN Bus - AutoCodes.com — U0020 Chevrolet Code - Low Speed CAN Bus

What does this mean?

What are the Possible Causes of the DTC U0020 Chevrolet?

If other codes are present, diagnose other codes first
Faulty Control Module
Control Module harness is open or shorted
Control Module circuit poor electrical connection

How to Fix the DTC U0020 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 does this mean?

Code Tech Notes

Controller Area Network (CAN)

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the U0020 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 U0020 Chevrolet code?

Need more information on how to fix the U0020 Chevrolet code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the U0020 Chevrolet code diagnosed by a professional: Find a repair shop in your area

Information for Specific Chevrolet Models

U0020 2014 Chevrolet Silverado — Low Speed CAN Bus
U0020 2015 Chevrolet Silverado — Low Speed CAN Bus
U0020 2016 Chevrolet Silverado — Low Speed CAN Bus
U0020 2017 Chevrolet Silverado — Low Speed CAN Bus
U0020 2018 Chevrolet Silverado — Low Speed CAN 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 U0020 Chevrolet Code

1. What is the U0020 OBDII code for Chevrolet related to the Low Speed CAN Bus?

The U0020 code specifically pertains to a communication issue on the Low Speed Controller Area Network (CAN) Bus in Chevrolet vehicles.

2. What are common symptoms of the U0020 OBDII code in a Chevrolet?

Common symptoms of the U0020 code may include intermittent or complete loss of communication with various control modules, malfunction indicator light (MIL) illumination, and possibly drivability issues.

3. What are possible causes of the U0020 OBDII code in a Chevrolet?

The U0020 code can be triggered by issues such as damaged wiring, loose connections, faulty control modules, corrosion in the CAN network, or a defective CAN bus.

4. How can I diagnose the U0020 OBDII code in my Chevrolet?

Diagnosing the U0020 code typically involves using a professional OBDII scanner to check for stored trouble codes, inspecting the CAN network wiring and connections, and performing pinpoint tests on the affected modules.

5. Is it safe to continue driving with the U0020 OBDII code present in a Chevrolet?

It is not recommended to drive your Chevrolet with the U0020 code active, as it can lead to potential communication issues between critical vehicle systems and affect overall performance.

6. How can I repair the U0020 OBDII code in my Chevrolet?

Repairing the U0020 code often involves repairing or replacing damaged wiring, ensuring secure connections, addressing corrosion in the CAN network, and replacing any faulty control modules if necessary.

7. Can the U0020 OBDII code in a Chevrolet be cleared/reset without fixing the underlying issue?

Clearing the U0020 code without addressing the root cause is not advisable, as the issue will likely resurface, and ongoing communication problems may persist.

8. Are there any common Chevrolet models prone to experiencing the U0020 OBDII code?

Various Chevrolet models equipped with a Low-Speed CAN Bus system may be susceptible to triggering the U0020 code, including but not limited to certain Silverado, Equinox, Traverse, and Malibu models.

9. How much does it typically cost to repair the U0020 OBDII code in a Chevrolet?

The cost of repairing the U0020 code in a Chevrolet can vary depending on the extent of the issue, the parts needed for replacement, and whether professional labor is required. Costs can range from a few hundred to over a thousand dollars.

10. Can a DIY enthusiast with automotive knowledge fix the U0020 OBDII code in a Chevrolet themselves?

While some DIY enthusiasts may have the skills to diagnose and repair the U0020 code, it is recommended to consult a professional technician or mechanic for complex electrical system issues to ensure proper diagnosis and repair.