AutoCodes – Buick – U0198 Buick

U0198 Buick Code - Lost Communication With Telematic Control Module

Quick Answer

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Common causes include Faulty Telematic Control Module, Telematic Control Module harness is open or shorted, Telematic 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: U0198 Buick indicates Lost Communication With Telematic Control Module.
Common causes: Common causes include Faulty Telematic Control Module, Telematic Control Module harness is open or shorted, Telematic 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 1,858

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 02, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code U0198 Buick Description

Modules connected to the high speed General Motor Local Area Network (GMLAN) serial data circuits monitor for serial data communications during normal vehicle operation. Operating information and commands are exchanged among the modules. The modules 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 module as an availability indication of the transmitter module. The supervision time-out period is 250 ms. Each message contains the identification number of the transmitter module. The Diagnostic Trouble Code (DTC) sets when a periodic message from the Telematic Control Module has not been received.

OBDII Code U0198 Buick - Lost Communication With Telematic Control Module - AutoCodes.com — U0198 Buick Code - Lost Communication With Telematic Control Module

What does this mean?

What are the Possible Causes of the DTC U0198 Buick?

Faulty Telematic Control Module
Telematic Control Module harness is open or shorted
Telematic Control Module circuit poor electrical connection

How to Fix the DTC U0198 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 U0198 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 U0198 Buick Code

What does the OBDII code U0198 mean on a Buick?

The U0198 code indicates that the vehicle's Telematic Control Module (TCM) has lost communication with other modules on the CAN (Controller Area Network) bus system.

What are the common symptoms of the U0198 code in a Buick?

Symptoms may include warning lights on the dashboard, such as the check engine light, malfunctioning telematics features like OnStar, or general connectivity issues.

What causes the U0198 code to appear in a Buick?

Common causes include a faulty Telematic Control Module, damaged wiring or connectors in the CAN bus, a blown fuse, or network communication issues between modules.

Can a weak battery cause the U0198 code in my Buick?

Yes, a weak or failing battery can cause communication errors between modules, potentially triggering the U0198 code.

How do I diagnose the U0198 code on my Buick?

Start by inspecting the wiring and connectors for damage or corrosion, check for blown fuses, and test the battery voltage. If no issues are found, a diagnostic scan tool may be needed to monitor communication signals.

Is it safe to drive my Buick with the U0198 code active?

While it may be safe to drive, features related to the Telematic Control Module, such as emergency communication systems, may not function properly, posing a potential safety risk.

How do I fix the U0198 code on my Buick?

Repairs may include replacing damaged wiring, repairing corroded or loose connectors, replacing a blown fuse, reprogramming the module, or replacing the Telematic Control Module if it is defective.

Can a software update resolve the U0198 code in my Buick?

Yes, in some cases, updating the vehicle's software or reprogramming the Telematic Control Module can resolve communication issues causing the code.

What tools are needed to troubleshoot the U0198 code on my Buick?

A diagnostic scan tool capable of reading manufacturer-specific codes and monitoring CAN bus communication, along with a multimeter for testing wiring and voltage, are essential.

Will disconnecting the battery clear the U0198 code in my Buick?

Disconnecting the battery may temporarily clear the code, but if the underlying issue isnâ€™t resolved, the code will likely return.