AutoCodes – Buick – U2146 Buick

U2146 Buick Code - Lost Communication With Shift Lever Module

Quick Answer

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Shift Lever Module (SLM), Shift Lever Module harness is open or shorted, Shift Lever 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: U2146 Buick indicates Lost Communication With Shift Lever Module.
Common causes: Common causes include Faulty Shift Lever Module (SLM), Shift Lever Module harness is open or shorted, Shift Lever 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 663

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 Jun 16, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U2146 Buick Description

Devices connected to the serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the devices. The devices have prerecorded information about what messages are needed to be exchanged on the serial data circuits, for each virtual network. The messages are supervised and also, some periodic messages are used by the receiver device as an availability indication of the transmitter device. Each message contains the identification number of the transmitter device. A loss of serial data communications Diagnostic Trouble Code (DTC) does not represent a failure of the devices that contain the stored code. The DTC will set when a supervised periodic message that includes the transmitter device availability has not been received.

OBDII Code U2146 Buick - Lost Communication With Shift Lever Module - AutoCodes.com — U2146 Buick Code - Lost Communication With Shift Lever Module

What does this mean?

What are the Possible Causes of the DTC U2146 Buick?

Faulty Shift Lever Module (SLM)
Shift Lever Module harness is open or shorted
Shift Lever Module circuit poor electrical connection

How to Fix the DTC U2146 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 U2146 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 U2146 Buick Code

1. What does OBDII code U2146 mean for a Buick?

U2146 indicates a loss of communication between the vehicle's shift lever module and other control modules on the communication network.

2. What are the common symptoms of code U2146 in a Buick?

Symptoms may include the inability to shift gears, the transmission stuck in one gear, a check engine light, or warning messages on the dashboard.

3. What causes code U2146 to appear in a Buick?

Common causes include faulty wiring or connectors, a malfunctioning shift lever module, issues with the CAN communication network, or a failing transmission control module (TCM).

4. Can a blown fuse cause code U2146 in my Buick?

Yes, a blown fuse related to the shift lever module or CAN network can disrupt communication and trigger the U2146 code.

5. How do I diagnose code U2146 on a Buick?

Start by checking for damaged or loose wiring and connectors near the shift lever module. Use a scan tool to verify module communication on the CAN network and test the shift lever module itself.

6. Is code U2146 serious, and can I drive with it?

It can be serious if it affects the vehicle's ability to shift gears properly. Driving may be unsafe, and the issue should be addressed promptly.

7. How much does it cost to fix code U2146 in a Buick?

Repair costs vary depending on the issue, ranging from $50 for simple wiring fixes to $500 or more if the shift lever module needs replacement.

8. Can I fix code U2146 on my Buick myself?

If the issue is caused by loose wiring or a blown fuse, you may be able to fix it yourself. However, diagnosing and replacing modules typically requires professional tools and expertise.

9. Does code U2146 require reprogramming after repairs?

In some cases, if the shift lever module is replaced, it may require reprogramming to ensure proper communication with the vehicle's other modules.

10. What tools are needed to diagnose code U2146 in a Buick?

A professional-grade OBDII scan tool with CAN network diagnostics and basic electrical testing tools, such as a multimeter, are essential for diagnosing this code.