Code U0106 on the 2023 Kia Sorento indicates lost communication with the glow plug control module. This code appears on diesel-equipped Sorento models, where glow plugs are essential for cold starting by preheating the combustion chambers.
Glow Plug System Function
Diesel engines don't use spark plugs - they rely on compression heat for ignition. In cold conditions, glow plugs heat the combustion chambers to ensure reliable starting. The glow plug control module manages preheat timing, monitors glow plug health, and communicates status to other vehicle systems.
Starting and Performance Effects
With U0106 active, cold starting becomes difficult or impossible depending on ambient temperature. The wait-to-start indicator may not illuminate properly, or the system may not activate glow plugs at all. Once warm, the engine runs normally since glow plugs aren't needed after startup. However, diagnostic warning lights remain on.
Diagnostic Approach
The glow plug control module is typically mounted on or near the engine. Check the module connector for corrosion from heat and moisture exposure. Verify power and ground supplies to the module. Failed individual glow plugs can affect module operation and communication. Temperature sensor inputs also affect glow plug timing calculations.
Repair Considerations
Many U0106 codes result from wiring issues rather than module failure. Test the glow plug circuit including individual plugs. If the module has failed, replacement requires Kia KDS programming. After repairs, verify proper glow plug operation by monitoring wait-to-start timing during cold starts.