Network Codes
1,532 OBD-II diagnostic trouble codes in this category.
Showing page 10 of 16 (1,532 codes total)
| Code | Description | Subsystem | Severity |
|---|---|---|---|
| U0607 | Lost Communication With Throttle/Pedal Position Sensor/Switch B | Module Communication | High |
| U0608 | Lost Communication With Throttle/Pedal Position Sensor/Switch C | Module Communication | High |
| U0609 | Lost Communication With Manifold Absolute Pressure/Barometric Pressure Sensor | ABS Communication | Critical |
| U060A | Lost Communication With Manifold Absolute Pressure Sensor B | ABS Communication | Critical |
| U060B | Lost Communication With Turbocharger/Supercharger Boost Sensor A | Module Communication | High |
| U060C | Lost Communication With Turbocharger/Supercharger Boost Sensor B | Module Communication | High |
| U060D | Lost Communication With Turbocharger/Supercharger Boost Sensor C | Module Communication | High |
| U060E | Lost Communication With Crankcase Pressure Sensor | Module Communication | High |
| U060F | Lost Communication With Mass or Volume Air Flow Sensor A | Module Communication | High |
| U0610 | Lost Communication With Mass or Volume Air Flow Sensor B | Module Communication | High |
| U0611 | Lost Communication With Intake Air Temperature Sensor 1 Bank 1 | Module Communication | High |
| U0612 | Lost Communication With Intake Air Temperature Sensor 1 Bank 2 | Module Communication | High |
| U0613 | Lost Communication With Intake Air Temperature Sensor 2 Bank 1 | Module Communication | High |
| U0614 | Lost Communication With Intake Air Temperature Sensor 2 Bank 2 | Module Communication | High |
| U0615 | Lost Communication With Engine Coolant Bypass Valve A | ECM Communication | Critical |
| U0616 | Lost Communication With Engine Coolant Bypass Valve B | ECM Communication | Critical |
| U0617 | Lost Communication With Engine Coolant Bypass Valve C | ECM Communication | Critical |
| U0618 | Lost Communication With Engine Coolant Bypass Valve D | ECM Communication | Critical |
| U0619 | Lost Communication With Reductant Level Sensor A | Module Communication | High |
| U061A | Lost Communication With Reductant Level Sensor B | Module Communication | High |
| U061B | Lost Communication With Reductant Level Sensor C | Module Communication | High |
| U061C | Lost Communication With Reductant Temperature Sensor A | Module Communication | High |
| U061D | Lost Communication With Reductant Temperature Sensor B | Module Communication | High |
| U061E | Lost Communication with Battery Isolation/Voltage Stabilization Control Module | EV/Hybrid | Critical |
| U061F | Lost Communication With Exhaust Gas Temperature Sensor Bank 1 Sensor 1 | Module Communication | High |
| U0620 | Lost Communication With Exhaust Gas Temperature Sensor Bank 1 Sensor 2 | Module Communication | High |
| U0621 | Lost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 1 | Module Communication | High |
| U0622 | Lost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 2 | Module Communication | High |
| U0623 | Lost Communication With Coolant Pump “A” | Module Communication | High |
| U0624 | Lost Communication With Coolant Pump “B” | Module Communication | High |
| U0625 | Lost Communication With Fuel Rail Pressure Sensor Bank 1 | Module Communication | High |
| U0626 | Lost Communication With A/C Refrigerant Pressure Sensor “A” | Module Communication | High |
| U0627 | Lost Communication With A/C Refrigerant Temperature Sensor “A” | Module Communication | High |
| U0628 | Lost Communication With A/C Refrigerant Pressure Sensor “B” | Module Communication | High |
| U0629 | Lost Communication With A/C Refrigerant Temperature Sensor “B” | Module Communication | High |
| U062A | Lost Communication With A/C Refrigerant Distribution Valve Actuator “A” | Module Communication | High |
| U062B | Lost Communication With A/C Refrigerant Distribution Valve Actuator “B” | Module Communication | High |
| U062C | Lost Communication With A/C Refrigerant Distribution Valve Actuator “C” | Module Communication | High |
| U062D | Lost Communication With A/C Refrigerant Distribution Valve Actuator “D” | Module Communication | High |
| U062E | Lost Communication With A/C Refrigerant Expansion Valve Actuator | Module Communication | High |
| U062F | Lost Communication With Coolant Pump C | Module Communication | High |
| U0630 | Lost Communication With Engine Coolant Temperature Sensor 4 | ECM Communication | Critical |
| U0631 | Lost Communication With Engine Coolant Temperature Sensor 5 | ECM Communication | Critical |
| U0632 | Lost Communication With Fan 1 | Module Communication | High |
| U0633 | Lost Communication With Fan 2 | Module Communication | High |
| U0634 | Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor A | EV/Hybrid | Critical |
| U0635 | Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor B | EV/Hybrid | Critical |
| U0636 | Lost Communication With Hybrid/EV Battery Pack Coolant Control Valve A | EV/Hybrid | Critical |
| U0637 | Lost Communication With Hybrid/EV Battery Pack Coolant Control Valve B | EV/Hybrid | Critical |
| U0638 | Lost Communication With Hybrid/EV Electronics Coolant Temperature Sensor A | EV/Hybrid | Critical |
| U0639 | Lost Communication With Hybrid/EV Electronics Coolant Temperature Sensor B | EV/Hybrid | Critical |
| U063A | Lost Communication With Hybrid/EV Electronics Coolant Temperature Sensor C | EV/Hybrid | Critical |
| U063B | Lost Communication With Coolant Bypass Valve Actuator A | Module Communication | High |
| U063C | Lost Communication With Coolant Bypass Valve Actuator B | Module Communication | High |
| U063D | Lost Communication With Hybrid/EV Electronics Coolant Pump A | EV/Hybrid | Critical |
| U063E | Lost Communication With Exhaust Heat Exchanger Bypass Valve Actuator A | Module Communication | High |
| U063F | Lost Communication With Engine Coolant Flow Control Valve Position Sensor | ECM Communication | Critical |
| U0640 | Lost Communication With EVAP Fuel Vapor Temperature Sensor Circuit | Module Communication | High |
| U0641 | Lost Communication With EVAP System Pressure Sensor/Switch Circuit A | Module Communication | High |
| U0642 | Lost Communication With EVAP System Pressure Sensor/Switch Circuit B | Module Communication | High |
| U0643 | Lost Communication With Turbocharger/Supercharger A Temperature Sensor | Module Communication | High |
| U0644 | Lost Communication With Wastegate Position Sensor A | Module Communication | High |
| U0645 | Lost Communication With Active Air Dam Module | Module Communication | High |
| U0646 | Lost Communication With Motor Electronics Coolant Pump A | Module Communication | High |
| U0647 | Lost Communication With Motor Electronics Coolant Pump B | Module Communication | High |
| U0648 | Lost Communication With Motor Electronics Coolant Pump C | Module Communication | High |
| U0649 | Lost Communication With Coolant Pump D | Module Communication | High |
| U064A | Lost Communication With Hybrid/EV Battery Pack Current Sensor A | EV/Hybrid | Critical |
| U064B | Lost Communication With Hybrid/EV Battery Pack Current Sensor B | EV/Hybrid | Critical |
| U064C | Lost Communication With Hybrid/EV Battery Pack Current Sensor C | EV/Hybrid | Critical |
| U064D | Lost Communication With Trailer Brake Control Switch | ABS Communication | Critical |
| U064E | Lost Communication With EGR Cooler Bypass Position Sensor Bank 1 | Module Communication | High |
| U064F | Lost Communication With Intake Manifold Runner Position Sensor Bank 1 | Module Communication | High |
| U0650 | Lost Communication With Exhaust Pressure Control Valve A Sensor/Switch | Module Communication | High |
| U0651 | Lost Communication With EGR Sensor A | Module Communication | High |
| U0652 | Lost Communication With EGR Sensor B | Module Communication | High |
| U0653 | Lost Communication With EGR Sensor C | Module Communication | High |
| U0654 | Lost Communication With Diesel Intake Air Flow A Position Sensor | Module Communication | High |
| U0655 | Lost Communication With Diesel Intake Air Flow B Position Sensor | Module Communication | High |
| U0656 | Lost Communication With Turbocharger/Supercharger Boost Control A Position Sensor | Module Communication | High |
| U0657 | Lost Communication With Turbocharger/Supercharger Bypass Valve A Position Sensor | Module Communication | High |
| U0658 | Lost Communication With Windshield Temperature Sensor | Module Communication | High |
| U0659 | Lost Communication With Left Front Temperature Actuator | Module Communication | High |
| U065A | Lost Communication With Right Front Temperature Actuator | Module Communication | High |
| U065B | Lost Communication With Left Front Mode Actuator | Module Communication | High |
| U065C | Lost Communication With Right Front Mode Actuator | Module Communication | High |
| U065D | Lost Communication With Air Intake Actuator | Module Communication | High |
| U065E | Lost Communication With Ram Air Actuator | Module Communication | High |
| U065F | Lost Communication With Left Rear Temperature Actuator A | Module Communication | High |
| U0660 | Lost Communication With Left Rear Temperature Actuator B | Module Communication | High |
| U0661 | Lost Communication With Right Rear Temperature Actuator A | Module Communication | High |
| U0662 | Lost Communication With Right Rear Temperature Actuator B | Module Communication | High |
| U0663 | Lost Communication With Rear Mode Actuator | Module Communication | High |
| U0664 | Lost Communication With Rear HVAC Air Cutoff Actuator | HVAC | Medium |
| U0665 | Lost Communication With Fuel Rail Pressure Sensor Bank 2 | Module Communication | High |
| U0666 | Lost Communication With Reductant Pressure Sensor | Module Communication | High |
| U0667 | Lost Communication With Engine Oil Temperature Sensor A | ECM Communication | Critical |
| U0668 | Lost Communication With Engine Oil Level Sensor Circuit | ECM Communication | Critical |
| U0669 | Lost Communication With EGR Sensor D | Module Communication | High |
| U066A | Lost Communication With EGR Sensor E | Module Communication | High |
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.