Lost Communication With Telematic Control Module
What does U0198 mean?
The U0198 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Telematic Control Module. This is a low severity code.
Common Symptoms
- Connected vehicle services unavailable
- Remote start from app not working
- Vehicle location tracking disabled
- OnStar or similar service not responding
- Emergency SOS button inoperative
Probable Causes (Ranked by Likelihood)
- Failed telematics control unit Very High
- Cellular antenna disconnected or damaged High
- Telematics subscription expired or deactivated Moderate
- Software update failure in telematics module Moderate
Step-by-Step Diagnostic Procedure
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Verify the telematics subscription is active with the service provider
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Check the cellular antenna connection (usually on the roof)
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Inspect the telematics module connector for corrosion
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Verify power and ground at the telematics module
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Check for software update availability through the dealer
Frequently Asked Questions
Can I drive with code U0198?
Yes, safe to drive. Connected services like remote start, vehicle tracking, and emergency calling will be unavailable but driving is not affected.
What causes U0198?
Often a failed telematics module or disconnected cellular antenna. Check your subscription status first since an expired plan can trigger this code.
Is U0198 expensive to fix?
Typically $100 to $600. Verify the subscription is active before spending money on repairs. Module replacement with service activation is on the higher end.