AutoCodes – Buick – U240D Buick

U240D Buick Code - Transmission Range Selector Control Module Powertrain Expansion CAN Bus Off

Quick Answer

The powertrain high-speed General Motors Local Area Network (GMLAN)serial data circuits are serial data buses used to communicate information between the devices. Common causes include Faulty Transmission Range Selector Control Module, Transmission Range Selector Control Module harness is open or shorted, Transmission Range Selector 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: U240D Buick indicates Transmission Range Selector Control Module Powertrain Expansion CAN Bus Off.
Common causes: Common causes include Faulty Transmission Range Selector Control Module, Transmission Range Selector Control Module harness is open or shorted, Transmission Range Selector 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 704

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 17, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U240D Buick Description

The powertrain high-speed General Motors Local Area Network (GMLAN)serial data circuits are serial data buses used to communicate information between the devices. The powertrain high speed GMLAN serial data circuits also connect directly to the X84 Data Link Connector (DLC) for programming purposes. If this serial data system is inoperative, the devices will still communicate with the scan tool due to other serial data systems but not with each other. The device setting the Diagnostic Trouble Code (DTC) has attempted to establish communications on the powertrain high-speed GMLAN serial data circuits more than 3 times.

OBDII Code U240D Buick - Transmission Range Selector Control Module Powertrain Expansion CAN Bus Off - AutoCodes.com — U240D Buick Code - Transmission Range Selector Control Module Powertrain Expansion CAN Bus Off

What does this mean?

What are the Possible Causes of the DTC U240D Buick?

Faulty Transmission Range Selector Control Module
Transmission Range Selector Control Module harness is open or shorted
Transmission Range Selector Control Module circuit poor electrical connection

How to Fix the DTC U240D 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 U240D 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 U240D Buick Code

What does the OBDII code U240D mean for a Buick?

The code U240D indicates a communication issue with the Transmission Range Selector Control Module, specifically that the Powertrain Expansion CAN Bus is offline.

What are the common symptoms associated with the U240D code?

Common symptoms include transmission shifting problems, incorrect gear selection, the check engine light being illuminated, and potential limp mode activation.

What causes the U240D code to trigger in a Buick?

The U240D code can be triggered by issues such as damaged wiring or connectors, a faulty Transmission Range Selector Control Module, or problems with the CAN Bus communication network.

How can I diagnose the U240D code?

Start by using an OBDII scanner to confirm the code and check for any additional codes. Inspect wiring and connectors for damage, and test the Transmission Range Selector Control Module to ensure it is functioning properly.

What are some potential repairs for the U240D code?

Repairs may include repairing or replacing damaged wiring or connectors, replacing the Transmission Range Selector Control Module, or addressing any faults in the CAN Bus system.

Can I drive my Buick with the U240D code?

It is not recommended to drive the vehicle with this code, as it may lead to transmission issues and could cause further damage or safety concerns.

Is resetting the code a permanent fix for U240D?

Resetting the code is not a permanent fix; if the underlying issue is not resolved, the code will likely reappear.

How can I prevent the U240D code from occurring again?

Regularly inspect and maintain the vehicle's electrical systems, ensure connectors are secure, and address any transmission issues promptly to minimize the risk of this code returning.

Should I take my Buick to a dealer for U240D code repairs?

While a dealer can provide specialized knowledge, a qualified independent mechanic with experience in GM vehicles can also effectively diagnose and repair the U240D code.