Lost Communication With Cellular Telematics Module
The U0291 code means the vehicle's onboard diagnostic system has detected: Lost Communication With Cellular Telematics Module. This is a low severity code.
- Keep driving?
- Yes, but fix soon
- DIY difficulty
- moderate
- Estimated cost
- $300 - $1,000 (parts and labor)
Network codes mean modules are not communicating. You need a scanner that reads all systems to find the problem.
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Common Symptoms
- Connected services not working
- Remote app features disabled
- Automatic crash notification unavailable
- Vehicle location not tracking
- SOS button not functional
Probable Causes (Ranked by Likelihood)
- Failed telematics control unit Very High
- Cellular antenna disconnected High
- CAN bus wiring fault to module Moderate
- SIM card failure or deactivation Low
Step-by-Step Diagnostic Procedure
-
Check cellular antenna connection
-
Verify telematics subscription status
-
Scan telematics module for codes
-
Test CAN bus at telematics module
Frequently Asked Questions
Can I drive with U0291?
Yes, but automatic crash notification and connected services will not work.
What causes U0291?
Usually a failed telematics control unit or disconnected antenna.
Is U0291 a safety concern?
Automatic crash notification may not work, so carry a charged cell phone.
Sources
This page is built from documented references. Verify against your own service info before repair work.
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