Network Codes
1,532 OBD-II diagnostic trouble codes in this category.
Showing page 5 of 16 (1,532 codes total)
| Code | Description | Subsystem | Severity |
|---|---|---|---|
| U0273 | Lost Communication With Lighting Driver Control Module “A” | Module Communication | High |
| U0274 | Lost Communication With Lighting Driver Control Module “B” | Module Communication | High |
| U0275 | Lost Communication With Lighting Driver Control Module “C” | Module Communication | High |
| U0276 | Lost Communication With Lighting Driver Control Module “D” | Module Communication | High |
| U0277 | Lost Communication With Seat Control Module K | Module Communication | High |
| U0278 | Lost Communication With Seat Control Module L | Module Communication | High |
| U0279 | Lost Communication with Haptic Control Module | Module Communication | High |
| U027A | Lost Communication With Battery Charger Control Module C | EV/Hybrid | Critical |
| U027B | Lost Communication with Battery Charger Control Module D | EV/Hybrid | Critical |
| U027C | Lost Communication With Off-Board Charger Control Module | Module Communication | High |
| U0284 | Lost Communication with Lane Departure Warning Module | ADAS | Medium |
| U0285 | Lost Communication With Active Grille Air Shutter Module B | Module Communication | High |
| U0286 | Lost Communication With Radiator Anti Tamper Device | Module Communication | High |
| U0287 | Lost Communication With Transmission Fluid Pump Module A | TCM Communication | Critical |
| U0288 | Lost Communication With DC/AC Converter Control Module A | Module Communication | High |
| U0289 | Lost Communication With DC/AC Converter Control Module B | Module Communication | High |
| U028A | Lost Communication With Transmission Fluid Pump Module B | TCM Communication | Critical |
| U028B | Lost Communication With Active Grille Air Shutter Module C | Module Communication | High |
| U028C | Lost Communication With Active Grille Air Shutter Module D | Module Communication | High |
| U028D | Lost Communication with Active Aerodynamic Feature Control Module A | Module Communication | High |
| U028E | Lost Communication with Active Aerodynamic Feature Control Module B | Module Communication | High |
| U028F | Lost Communication with Active Aerodynamic Feature Control Module C | Module Communication | High |
| U0290 | Lost Communication with Active Aerodynamic Feature Control Module D | Module Communication | High |
| U0291 | Lost Communication With Gear Shift Control Module B | Module Communication | High |
| U0292 | Lost Communication With Drive Motor Control Module B | Module Communication | High |
| U0293 | Lost Communication with Hybrid Powertrain Control Module | EV/Hybrid | Critical |
| U0294 | Lost Communication With Powertrain Control Monitor Module | Module Communication | High |
| U0295 | Lost Communication With AC/AC Converter Control Module | Module Communication | High |
| U0296 | Lost Communication With AC/DC Converter Control Module A | Module Communication | High |
| U0297 | Lost Communication With AC/DC Converter Control Module B | Module Communication | High |
| U0298 | Lost Communication With DC/DC Converter Control Module A | Module Communication | High |
| U0299 | Lost Communication With DC/DC Converter Control Module B | Module Communication | High |
| U029A | Lost Communication With Hybrid/EV Battery Pack Sensor Module | EV/Hybrid | Critical |
| U029B | Lost Communication With Drive Motor Control Module C | Module Communication | High |
| U029C | Lost Communication With Drive Motor Control Module D | Module Communication | High |
| U029D | Lost Communication With NOx Sensor A | Module Communication | High |
| U029E | Lost Communication With NOx Sensor B | Module Communication | High |
| U029F | Lost Communication With Evaporative Emission System Leak Detection Control Module | Module Communication | High |
| U02A0 | Invalid Data Received From Hybrid/EV Battery Interface Control Module D | Data Integrity | High |
| U02A1 | Lost Communication With NOx Sensor C | Module Communication | High |
| U02A2 | Lost Communication With Reductant Quality Module | Module Communication | High |
| U02A3 | Lost Communication With Particulate Matter Sensor | Module Communication | High |
| U02A4 | Lost Communication With NH3 Sensor | Module Communication | High |
| U02A5 | Lost Communication With Reductant Heater Control Module | Module Communication | High |
| U02A6 | Lost Communication With Safety Integration Control Module | Module Communication | High |
| U02A7 | Lost Communication With Engine Sound Control 1 | ECM Communication | Critical |
| U02A8 | Lost Communication With Engine Sound Control 2 | ECM Communication | Critical |
| U02A9 | Lost Communication With Charge Air Cooler Coolant Pump A | Module Communication | High |
| U02AA | Lost Communication With Engine Disconnect Clutch | ECM Communication | Critical |
| U02AB | Lost Communication With Vehicle Thermal Management Control Module | Module Communication | High |
| U02AC | Lost Communication With Turbocharger/Supercharger Boost Control A | Module Communication | High |
| U02AD | Lost Communication With Turbocharger/Supercharger Boost Control B | Module Communication | High |
| U02AE | Lost Communications With Hybrid/EV Battery Coolant Pump | EV/Hybrid | Critical |
| U02AF | Lost Communication With Turbocharger Turbine Inlet Valve Position Sensor | Module Communication | High |
| U02B0 | Lost Communication With Turbocharger/Supercharger Boost Control B Position Sensor | Module Communication | High |
| U02B1 | Lost Communication With Comfort and Convenience Display A | Module Communication | High |
| U02B2 | Lost Communication With Comfort and Convenience Display B | Module Communication | High |
| U02B3 | Lost Communication With Driver Monitoring System Module | Module Communication | High |
| U02B4 | Lost Communication With Front Radar Module A | Module Communication | High |
| U02B5 | Lost Communication With Front Radar Module B | Module Communication | High |
| U02B6 | Lost Communication With Rear Radar Module A | Module Communication | High |
| U02B7 | Lost Communication With Rear Radar Module B | Module Communication | High |
| U02B8 | Lost Communication With Rear Radar Module C | Module Communication | High |
| U02B9 | Lost Communication With Rear Radar Module D | Module Communication | High |
| U02BA | Lost Communication With Hybrid/EV Electronics Coolant Pump B | EV/Hybrid | Critical |
| U02BB | Lost Communications with EVAP System Purge Pump | Module Communication | High |
| U02BC | Lost Communication With Localization and Mapping Module | Module Communication | High |
| U02BD | Lost Communication With Night Vision Control Module | Module Communication | High |
| U02BE | Lost Communication With Trailer Backup Assist Control Module | Module Communication | High |
| U02BF | Lost Communication With Interior Lighting Control Module B | Module Communication | High |
| U02C0 | Lost Communication With Active Radiator Air Flow Control Module A | Module Communication | High |
| U02C1 | Lost Communication With Hybrid/EV Electronics Coolant Pump C | EV/Hybrid | Critical |
| U0300 | Software Incompatibility with ECM/PCM | Software | High |
| U0301 | Software Incompatibility with TCM | Software | High |
| U0302 | Software Incompatibility With Transmission Control Module | Software | Medium |
| U0303 | Software Incompatibility With Transfer Case Control Module | Software | Medium |
| U0304 | Software Incompatibility With Gear Shift Control Module A | Software | Medium |
| U0305 | Software Incompatibility with Cruise Control Module | Software | Medium |
| U0306 | Software Incompatibility With Fuel Injector Control Module | Software | Medium |
| U0307 | Software Incompatibility With Glow Plug Control Module 1 | Software | Medium |
| U0308 | Software Incompatibility With Throttle Actuator Control Module | Software | Medium |
| U0309 | Software Incompatibility With Alternative Fuel Control Module | Software | Medium |
| U030A | Software Incompatibility With Evaporative Emission System Leak Detection Control Module | Software | Medium |
| U030B | Software Incompatibility With Glow Plug Control Module 2 | Software | Medium |
| U030C | Software Incompatibility With Reductant Quality Module | Software | Medium |
| U030D | Software Incompatibility With NOx Sensor A | Software | Medium |
| U030E | Software Incompatibility With NOx Sensor B | Software | Medium |
| U030F | Software Incompatibility With Reductant Control Module | Software | Medium |
| U0310 | Software Incompatibility With Fuel Pump Control Module | Software | Medium |
| U0311 | Software Incompatibility With Drive Motor Control Module | Software | Medium |
| U0312 | Software Incompatibility With Battery Energy Control Module A | Software | Medium |
| U0313 | Software Incompatibility With Battery Energy Control Module B | Software | Medium |
| U0314 | Software Incompatibility With Four-Wheel Drive Clutch Control Module | Software | Medium |
| U0315 | Software Incompatibility With Anti-Lock Brake System (ABS) Control Module | Software | Medium |
| U0316 | Software Incompatibility With Vehicle Dynamics Control Module | Software | Medium |
| U0317 | Software Incompatibility With Park Brake Control Module | Software | Medium |
| U0318 | Software Incompatibility With Brake System Control Module A | Software | Medium |
| U0319 | Software Incompatibility With Steering Effort Control Module | Software | Medium |
| U031A | Software Incompatibility With Transmission Range Control Module | Software | Medium |
| U031B | Software Incompatibility With DC/DC Converter Control Module A | Software | Medium |
About Network Codes
This page lists all 1,532 OBD-II diagnostic trouble codes classified under the Network category. These codes are stored by your vehicle's onboard computer when a sensor detects a malfunction in the network system. Each code begins with a letter indicating the system (P for Powertrain, B for Body, C for Chassis, U for Network) followed by four digits that identify the specific fault.
When your check engine light comes on, an OBD-II scanner reads these stored codes to help pinpoint the problem. Generic codes (where the second digit is 0) follow the SAE J2012 standard and mean the same thing on every vehicle. Manufacturer-specific codes (where the second digit is 1) may have different meanings depending on the vehicle brand.
Click any code in the table above to see its full description, possible causes, common symptoms, and step-by-step repair guidance. Use the search box to quickly find a specific code within this category.