AutoCodes – Chevrolet – U1024 Chevrolet

U1024 Chevrolet Code - Lost Communications With Transmission Control Module

Quick Answer

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission 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: U1024 Chevrolet indicates Lost Communications With Transmission Control Module.
Common causes: Common causes include Faulty Transmission Control Module (TCM), Transmission Control Module harness is open or shorted, Transmission 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 3,885

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 Apr 22, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U1024 Chevrolet Description

Modules connected to the class 2 serial data circuit monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. When a module receives a message for a critical operating parameter, the module records the identification number of the module which sent the message for the state of health monitoring/node alive messages. A critical operating parameter is one which, when not received, requires that the module use a default value for that parameter. Once an identification number is learned by a module, it will monitor for that module node alive message. Each module on the class 2 serial data circuit is required to send a Node Alive message every 2 seconds. When no message is detected from a learned identification number for 5 seconds, a Diagnostic Trouble Code (DTC) U1024 is set.

OBDII Code U1024 Chevrolet - Lost Communications With Transmission Control Module - AutoCodes.com — U1024 Chevrolet Code - Lost Communications With Transmission Control Module

What does this mean?

What are the Possible Causes of the DTC U1024 Chevrolet?

Faulty Transmission Control Module (TCM)
Transmission Control Module harness is open or shorted
Transmission Control Module circuit poor electrical connection

How to Fix the DTC U1024 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 U1024 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.

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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 U1024 Chevrolet Code

1. What does the OBDII code U1024 mean on a Chevrolet?

U1024 indicates a loss of communication between the Engine Control Module (ECM) and the Transmission Control Module (TCM).

2. What are the common symptoms of code U1024 in a Chevrolet?

Symptoms may include a check engine light, delayed or harsh shifting, transmission stuck in a single gear (limp mode), or poor vehicle performance.

3. What causes the U1024 code on a Chevrolet?

Common causes include a faulty TCM, damaged wiring or connectors, issues with the CAN bus network, or a failing ECM.

4. Can a bad battery cause the U1024 code?

Yes, a weak or failing battery can cause communication issues between modules, potentially triggering the U1024 code.

5. How can I diagnose the U1024 code on my Chevrolet?

Start by inspecting the TCM and ECM connections, checking for damaged wiring, testing the battery voltage, and using a scan tool to monitor CAN bus communication.

6. Is it safe to drive with the U1024 code on a Chevrolet?

It may be unsafe, as the vehicle could enter limp mode, affecting performance and making it difficult to drive normally.

7. What repairs are typically needed for the U1024 code?

Repairs may include fixing or replacing damaged wiring, cleaning or reconnecting module connectors, replacing a faulty TCM, or reprogramming the affected modules.

8. How much does it cost to fix the U1024 code on a Chevrolet?

Repair costs vary depending on the cause but can range from $100 for simple wiring repairs to $1,000 or more for TCM replacement and programming.

9. Can clearing the U1024 code fix the issue?

Clearing the code may temporarily remove the check engine light, but the underlying issue must be addressed to prevent the code from returning.

10. Do I need a professional mechanic to fix the U1024 code?

While basic inspections can be done at home, diagnosing and repairing communication issues often require specialized tools and expertise, so consulting a professional is recommended.