U2105 on 2003-2011 Saab 9-3 (Linear, Arc, Vector, Aero) — CAN Bus — No Communication With ECM/ECU (Manufacturer-Specific)
1 vehicles · 1 makes
Most Reported On
U2105 is an OBD-II diagnostic trouble code meaning “CAN Bus — No Communication With ECM/ECU (Manufacturer-Specific).” U2105 is a manufacturer-specific CAN bus code that generally means a module reported no communication with the engine control module (ECM/ECU) over the network. When the ECM cannot be reached, engine-related coordination breaks down, which can cause drivability problems, no-start conditions, or multiple warning lights. Because it can affect the engine controller, it should be addressed promptly. This code is most commonly reported on 2003-2011 Saab 9-3 (Linear, Arc, Vector, Aero).
Common Causes
Diagnostic Tools
U2105 does not use the standard P/B/C/U prefix. It may be a manufacturer-specific code, so verify that a scanner supports your exact year, model and module before buying.
FAQ
What does U2105 mean?
U2105 stands for "CAN Bus — No Communication With ECM/ECU (Manufacturer-Specific)." U2105 is a manufacturer-specific CAN bus code that generally means a module reported no communication with the engine control module (ECM/ECU) over the network. When the ECM cannot be reached, engine-related coordination breaks down, which can cause drivability problems, no-start conditions, or multiple warning lights. Because it can affect the engine controller, it should be addressed promptly.
What are the most common causes of U2105?
The most common causes of U2105 are: ECM not powered (blown fuse, failed relay), Damaged or open CAN bus wiring to the ECM, Faulty engine control module, Loose or corroded ECM connector, Poor ground or high-resistance ground, Low or unstable battery voltage, Module configuration / programming error. The specific cause varies by vehicle.
How much does it cost to fix U2105?
Repair costs vary widely depending on the root cause and vehicle.
Which vehicles are affected by U2105?
Au7o has documented U2105 across 1 vehicle models from 1 manufacturers: Saab.
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.