Network Codes
1,532 OBD-II diagnostic trouble codes in this category.
Showing page 14 of 16 (1,532 codes total)
| Code | Description | Subsystem | Severity |
|---|---|---|---|
| U1246 | SCP (J1850) Invalid or Missing Data for Primary Id | CAN Bus | Medium |
| U1247 | SCP (J1850) Invalid or Missing Data for Primary Id | CAN Bus | Medium |
| U1248 | SCP (J1850) Invalid or Missing Data for Time / Date | CAN Bus | Medium |
| U1249 | SCP (J1850) Invalid or Missing Data for Time / Date | CAN Bus | Medium |
| U1250 | SCP (J1850) Invalid or Missing Data for Vehicle Id (VIN) | CAN Bus | Medium |
| U1251 | SCP (J1850) Invalid or Missing Data for Vehicle Id (VIN) | CAN Bus | Medium |
| U1252 | SCP (J1850) Invalid or Missing Data for Class A Functions | CAN Bus | Medium |
| U1253 | SCP (J1850) Invalid or Missing Data for Class A Functions | CAN Bus | Medium |
| U1254 | SCP (J1850) Invalid or Missing Data for Network Control | CAN Bus | Medium |
| U1255 | SCP (J1850) Invalid or Missing Data for Network Control | CAN Bus | Medium |
| U1260 | SCP (J1850) Single Ended (+) Circuit Failure | Communication | Medium |
| U1261 | SCP Communication Bus Fault | SCP Bus | High |
| U1262 | SCP Communication Bus Performance | SCP Bus | Medium |
| U1300 | Lost Communication with Target Module | Module Communication | Medium |
| U1305 | CAN C Bus Off | CAN Bus | High |
| U1308 | SCP (J1850) Invalid or Missing Data for Function Read Engine Torque | CAN Bus | Medium |
| U1341 | SCP (J1850) Invalid or Missing Data for Function Read Vehicle Speed | CAN Bus | Medium |
| U1430 | SCP (J1850) Invalid or Missing Data for Function Read Fuel System | CAN Bus | Medium |
| U1451 | SCP (J1850) Invalid or Missing Data for Function Read Audible Warnings / Anti-Theft Module, Vehicle Immobilized | CAN Bus | Medium |
| U1612 | SCP (J1850) Lack of Acknowledgment for Primary Id | Communication | Medium |
| U1736 | SCP (J1850) Lack of Acknowledgment for Telltales | Communication | Medium |
| U1750 | SCP (J1850) Lack of Acknowledgment for Audible Warnings | Communication | Medium |
| U1794 | SCP (J1850) Lack of Acknowledgment for Mirrors | Communication | Medium |
| U1797 | SCP (J1850) Lack of Acknowledgment for Door Locks | Communication | Medium |
| U1798 | SCP (J1850) Lack of Acknowledgment for External Access (Doors) | Communication | Medium |
| U1806 | SCP (J1850) Lack of Acknowledgment for Primary Id | Communication | Medium |
| U1900 | CAN Communication Bus Fault (General) | CAN Bus | High |
| U1950 | UPB Communication Bus Fault | CAN Bus | Medium |
| U2000 | CAN System Error | CAN Bus | High |
| U2001 | Audio Tape Deck Unit is Not Responding | Communication | Medium |
| U2002 | Audio Bezel is Not Responding | Communication | Medium |
| U2003 | Audio Compact Disk / Disk Jockey Unit is Not Responding | Communication | Medium |
| U2004 | Audio Steering Wheel Control Unit is Not Responding | Communication | Medium |
| U2005 | Audio Rear Integrated Control Panel Unit is Not Responding | Communication | Medium |
| U2006 | Audio Remote Climate Control Unit is Not Responding | Communication | Medium |
| U2007 | Audio Navigation Unit is Not Responding | Communication | Medium |
| U2008 | Audio Phone is Not Responding | Communication | Medium |
| U2009 | Audio Front Control Module (ACM) is Not Responding | Communication | Medium |
| U2010 | Module is Not Responding (Non SCP) | Communication | Medium |
| U2011 | Module Transmitted Invalid Data (Non SCP) | CAN Bus | Medium |
| U2012 | Communication Bus Error (Non SCP) | CAN Bus | Medium |
| U2013 | Compass Module is not Responding | Communication | Medium |
| U2014 | Audio Subwoofer Unit is Not Responding | Communication | Medium |
| U2015 | Signal Link Fault (Non SCP) | Communication | Medium |
| U2016 | Signal Link Short to Ground (Non SCP) / From NGV Module | Communication | Medium |
| U2017 | Driver Side Crash Sensor Communication Fault (Non SCP) | Communication | Medium |
| U2018 | Passenger Side Crash Sensor Communication Fault (Non SCP) | Communication | Medium |
| U2019 | Audio Voice Module Not Responding | Communication | Medium |
| U2020 | Audio Center Amp is not responding | Communication | Medium |
| U2021 | Invalid /fault data received (Non SCP) | CAN Bus | Medium |
| U2100 | CAN Communication Timeout | CAN Bus | Medium |
| U2106 | Communication Bus A Fault | CAN Bus | High |
| U2150 | SCP (J1850) Invalid Data from REM | CAN Bus | Medium |
| U2152 | SCP (J1850) Invalid Data from GEM | CAN Bus | Medium |
| U2160 | SCP (J1850) Invalid Data from IC | CAN Bus | Medium |
| U2195 | CAN Configuration Error | Configuration | Medium |
| U2300 | Communication Error With Control Module | Module Communication | Medium |
| U2500 | CAN Communication Performance Error | CAN Bus | Medium |
| U3000 | Control Module Software Incompatibility | Software | High |
| U3001 | Control Module Improper Shutdown Performance | Network Communication | Medium |
| U3002 | Vehicle Identification Number | Network Communication | Medium |
| U3003 | Battery Voltage Low (Module) | Power Supply | Medium |
| U3004 | Accessory Power Relay | Network Communication | Medium |
| U3005 | Retained Accessory Power | Network Communication | Medium |
| U3006 | Control Module Input Power A Circuit/Open | Network Communication | Medium |
| U3007 | Control Module Input Power B Circuit/Open | Network Communication | Medium |
| U3008 | Control Module Ground A | Network Communication | Medium |
| U3009 | Control Module Ground B | Network Communication | Medium |
| U300A | Ignition Switch | Network Communication | Medium |
| U300B | Ignition Input Accessory/On/Start | Network Communication | Medium |
| U300C | Ignition Input Off/On/Start | Network Communication | Medium |
| U300D | Ignition Input On/Start | Network Communication | Medium |
| U300E | Ignition Input On | Network Communication | Medium |
| U300F | Ignition Input Accessory | Network Communication | Medium |
| U3010 | Ignition Input Start | Network Communication | Medium |
| U3011 | Ignition Input Off | Network Communication | Medium |
| U3012 | Control Module Improper Wake-up Performance | Network Communication | Medium |
| U3013 | Control Module Input Power C Circuit/Open | Network Communication | Medium |
| U3014 | Control Module Input Power D Circuit/Open | Network Communication | Medium |
| U3015 | Control Module Ground C | Network Communication | Medium |
| U3016 | Control Module Ground D | Network Communication | Medium |
| U3017 | Control Module Timer/Clock Performance | Network Communication | Medium |
| U3018 | Control Module Input Power Circuit A/B Correlation | Network Communication | Medium |
| U3019 | Control Module Input Power Circuit B/C Correlation | Network Communication | Medium |
| U301A | Control Module Wake-up Circuit A/Open | Network Communication | Medium |
| U301B | Control Module Wake-up Circuit A Low | Network Communication | Medium |
| U301C | Control Module Wake-up Circuit A High | Network Communication | Medium |
| U301D | Control Module Wake-up Circuit A Performance | Network Communication | Medium |
| U301E | Control Module Wake-up Circuit B/Open | Network Communication | Medium |
| U301F | Control Module Wake-up Circuit B Low | Network Communication | Medium |
| U3020 | Control Module Wake-up Circuit B High | Network Communication | Medium |
| U3021 | Control Module Wake-up Circuit B Performance | Network Communication | Medium |
| U3022 | Ignition Input Accessory/Off | Network Communication | Medium |
| U3023 | Control Module Input Power Circuit A - Ignition Input On/Start Circuit Correlation | Network Communication | Medium |
| U3024 | Control Module Input Power Circuit B - Ignition Input On/Start Circuit Correlation | Network Communication | Medium |
| U3025 | Control Module A Disable Circuit/Open | Network Communication | Medium |
| U3026 | Control Module A Disable Circuit Low | Network Communication | Medium |
| U3027 | Control Module A Disable Circuit High | Network Communication | Medium |
| U3028 | Control Module A Disable Feedback Circuit | Network Communication | Medium |
| U3029 | Control Module A Disable Feedback Circuit Low | Network Communication | 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.