OBD-II Network Communication Diagnostic Codes (U0600-U1000)

In general the wiring harnesses itself will never get a short or have a open within the harness unless its been in a fire or had mechanical damage done to the harness. Sometimes the harness may experience wire fatigue breakage when the harness is subjected to being constantly flexed back and forth.

The harness connectors sometimes fail due to mechanical damage or they become faulty because of corrosion and rust within the connector itself causing the contact pins to no longer carry a signal to the other modules.

So start by first inspecting the wiring harness and connectors for obvious damage or the connector just being loose. If the connectors and the harness passes the inspection then maybe you have a faulty computer module. But before even doing that make sure the battery and the charging system are good and supplying the proper voltages to the various modules.

Diagnostic Code U0601

Lost Communication With Particulate Filter Pressure Sensor A

Diagnostic Code U0602

Lost Communication With Particulate Filter Pressure Sensor B

Diagnostic Code U0603

Lost Communication With Fuel Pressure Sensor A

Diagnostic Code U0604

Lost Communication With Fuel Pressure Sensor B

Diagnostic Code U0605

Lost communication With A/C Refrigerant Sensor A

Diagnostic Code U0606

Lost Communication With Throttle/Pedal Position Sensor/Switch A

Diagnostic Code U0607

Lost Communication With Throttle/Pedal Position Sensor/Switch B

Diagnostic Code U0608

Lost Communication With Throttle/Pedal Position Sensor/Switch C

Diagnostic Code U0609

Lost Communication With Manifold Absolute Pressure/Barometric Pressure Sensor

Diagnostic Code U060A

Lost Communication With Manifold Absolute Pressure Sensor B

Diagnostic Code U060B

Lost Communication With Turbocharger/Supercharger Boost Sensor A

Diagnostic Code U060C

Lost Communication With Turbocharger/Supercharger Boost Sensor B

Diagnostic Code U060D

Lost Communication With Turbocharger/Supercharger Boost Sensor C

Diagnostic Code U060E

Lost Communication With Crankcase Pressure Sensor

Diagnostic Code U060F

Lost Communication With Mass or Volume Air Flow Sensor A

Diagnostic Code U0610

Lost Communication With Mass or Volume Air Flow Sensor B

Diagnostic Code U0611

Lost Communication With Intake Air Temperature Sensor 1 Bank 1

Diagnostic Code U0612

Lost Communication With Intake Air Temperature Sensor 1 Bank 2

Diagnostic Code U0613

Lost Communication With Intake Air Temperature Sensor 2 Bank 1

Diagnostic Code U0614

Lost Communication With Intake Air Temperature Sensor 2 Bank 2

Diagnostic Code U0615

Lost Communication With Engine Coolant Bypass Valve A

Diagnostic Code U0616

Lost Communication With Engine Coolant Bypass Valve B

Diagnostic Code U0617

Lost Communication With Engine Coolant Bypass Valve C

Diagnostic Code U0618

Lost Communication With Engine Coolant Bypass Valve D

Diagnostic Code U0619

Lost Communication With Reductant Level Sensor A

Diagnostic Code U061A

Lost Communication With Reductant Level Sensor B

Diagnostic Code U061B

Lost Communication With Reductant Level Sensor C

Diagnostic Code U061C

Lost Communication With Reductant Temperature Sensor A

Diagnostic Code U061D

Lost Communication With Reductant Temperature Sensor B

Diagnostic Code U061E

Lost Communication with Battery Isolation/Voltage Stabilization Control Module

Diagnostic Code U061F

Lost Communication With Exhaust Gas Temperature Sensor Bank 1 Sensor 1

Diagnostic Code U0620

Lost Communication With Exhaust Gas Temperature Sensor Bank 1 Sensor 2

Diagnostic Code U0621

Lost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 1

Diagnostic Code U0622

Lost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 2

Diagnostic Code U0623

Lost Communication With Coolant Pump “A”

Diagnostic Code U0624

Lost Communication With Coolant Pump “B”

Diagnostic Code U0625

Lost Communication With Fuel Rail Pressure Sensor Bank 1

Diagnostic Code U0626

Lost Communication With A/C Refrigerant Pressure Sensor “A”

Diagnostic Code U0627

Lost Communication With A/C Refrigerant Temperature Sensor “A”

Diagnostic Code U0628

Lost Communication With A/C Refrigerant Pressure Sensor “B”

Diagnostic Code U0629

Lost Communication With A/C Refrigerant Temperature Sensor “B”

Diagnostic Code U062A

Lost Communication With A/C Refrigerant Distribution Valve Actuator “A”

Diagnostic Code U062B

Lost Communication With A/C Refrigerant Distribution Valve Actuator “B”

Diagnostic Code U062C

Lost Communication With A/C Refrigerant Distribution Valve Actuator “C”

Diagnostic Code U062D

Lost Communication With A/C Refrigerant Distribution Valve Actuator “D”

Diagnostic Code U062E

Lost Communication With A/C Refrigerant Expansion Valve Actuator

Diagnostic Code U062F

Lost Communication With Coolant Pump C

Diagnostic Code U0630

Lost Communication With Engine Coolant Temperature Sensor 4

Diagnostic Code U0631

Lost Communication With Engine Coolant Temperature Sensor 5

Diagnostic Code U0632

Lost Communication With Fan 1

Diagnostic Code U0633

Lost Communication With Fan 2

Diagnostic Code U0634

Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor A

Diagnostic Code U0635

Lost Communication With Hybrid/EV Battery Pack Coolant Temperature Sensor B

Diagnostic Code U0636

Lost Communication With Hybrid/EV Battery Pack Coolant Control Valve A

Diagnostic Code U0637

Lost Communication With Hybrid/EV Battery Pack Coolant Control Valve B

Diagnostic Code U0638

Lost Communication With Hybrid/EV Electronics Coolant Temperature Sensor A

Diagnostic Code U0639

Lost Communication With Hybrid/EV Electronics Coolant Temperature Sensor B

Diagnostic Code U063A

Lost Communication With Hybrid/EV Electronics Coolant Temperature Sensor C

Diagnostic Code U063B

Lost Communication With Coolant Bypass Valve Actuator A

Diagnostic Code U063C

Lost Communication With Coolant Bypass Valve Actuator B

Diagnostic Code U063D

Lost Communication With Hybrid/EV Electronics Coolant Pump A

Diagnostic Code U063E

Lost Communication With Exhaust Heat Exchanger Bypass Valve Actuator A

Diagnostic Code U063F

Lost Communication With Engine Coolant Flow Control Valve Position Sensor

Diagnostic Code U0640

Lost Communication With EVAP Fuel Vapor Temperature Sensor Circuit

Diagnostic Code U0641

Lost Communication With EVAP System Pressure Sensor/Switch Circuit A

Diagnostic Code U0642

Lost Communication With EVAP System Pressure Sensor/Switch Circuit B

Diagnostic Code U0643

Lost Communication With Turbocharger/Supercharger A Temperature Sensor

Diagnostic Code U0644

Lost Communication With Wastegate Position Sensor A

Diagnostic Code U0645

Lost Communication With Active Air Dam Module

Diagnostic Code U0646

Lost Communication With Motor Electronics Coolant Pump A

Diagnostic Code U0647

Lost Communication With Motor Electronics Coolant Pump B

Diagnostic Code U0648

Lost Communication With Motor Electronics Coolant Pump C

Diagnostic Code U0649

Lost Communication With Coolant Pump D

Diagnostic Code U064A

Lost Communication With Hybrid/EV Battery Pack Current Sensor A

Diagnostic Code U064B

Lost Communication With Hybrid/EV Battery Pack Current Sensor B

Diagnostic Code U064C

Lost Communication With Hybrid/EV Battery Pack Current Sensor C

Diagnostic Code U064D

Lost Communication With Trailer Brake Control Switch

Diagnostic Code U064E

Lost Communication With EGR Cooler Bypass Position Sensor Bank 1

Diagnostic Code U064F

Lost Communication With Intake Manifold Runner Position Sensor Bank 1

Diagnostic Code U0650

Lost Communication With Exhaust Pressure Control Valve A Sensor/Switch

Diagnostic Code U0651

Lost Communication With EGR Sensor A

Diagnostic Code U0652

Lost Communication With EGR Sensor B

Diagnostic Code U0653

Lost Communication With EGR Sensor C

Diagnostic Code U0654

Lost Communication With Diesel Intake Air Flow A Position Sensor

Diagnostic Code U0655

Lost Communication With Diesel Intake Air Flow B Position Sensor

Diagnostic Code U0656

Lost Communication With Turbocharger/Supercharger Boost Control A Position Sensor

Diagnostic Code U0657

Lost Communication With Turbocharger/Supercharger Bypass Valve A Position Sensor

Diagnostic Code U0658

Lost Communication With Windshield Temperature Sensor

Diagnostic Code U0659

Lost Communication With Left Front Temperature Actuator

Diagnostic Code U065A

Lost Communication With Right Front Temperature Actuator

Diagnostic Code U065B

Lost Communication With Left Front Mode Actuator

Diagnostic Code U065C

Lost Communication With Right Front Mode Actuator

Diagnostic Code U065D

Lost Communication With Air Intake Actuator

Diagnostic Code U065E

Lost Communication With Ram Air Actuator

Diagnostic Code U065F

Lost Communication With Left Rear Temperature Actuator A

Diagnostic Code U0660

Lost Communication With Left Rear Temperature Actuator B

Diagnostic Code U0661

Lost Communication With Right Rear Temperature Actuator A

Diagnostic Code U0662

Lost Communication With Right Rear Temperature Actuator B

Diagnostic Code U0663

Lost Communication With Rear Mode Actuator

Diagnostic Code U0664

Lost Communication With Rear HVAC Air Cutoff Actuator

Diagnostic Code U0665

Lost Communication With Fuel Rail Pressure Sensor Bank 2

Diagnostic Code U0666

Lost Communication With Reductant Pressure Sensor

Diagnostic Code U0667

Lost Communication With Engine Oil Temperature Sensor A

Diagnostic Code U0668

Lost Communication With Engine Oil Level Sensor Circuit

Diagnostic Code U0669

Lost Communication With EGR Sensor D

Diagnostic Code U066A

Lost Communication With EGR Sensor E

Diagnostic Code U066B

Lost Communication With Turbocharger/Supercharger Bypass Valve B Position Sensor

Diagnostic Code U066C

Lost Communication With Exhaust Heat Exchanger Bypass Valve Actuator B

Diagnostic Code U066D

Lost Communication With Charge Air Cooler Temperature Sensor Bank 1

Diagnostic Code U066E

Lost Communication With Charge Air Cooler Temperature Sensor Bank 2

Diagnostic Code U066F

Lost Communication With Low Pressure Fuel System Sensor

Diagnostic Code U0670

Lost Communication With Fuel Temperature Sensor A

Diagnostic Code U0671

Lost Communication With Fuel Temperature Sensor B

Diagnostic Code U0672

Lost Communication With Engine Coolant Pump

Diagnostic Code U0673

Lost Communication With Ion Sense Module

Diagnostic Code U0674

Lost Communication With Wastegate Position Sensor B

Diagnostic Code U0675

Lost Communication With Turbocharger/Supercharger Speed Sensor A

Diagnostic Code U0676

Lost Communication With Fuel Level Sensor A

Diagnostic Code U0677

Lost Communication With Fuel Level Sensor B

Diagnostic Code U0678

Lost Communication With Fuel Level Sensor C

Diagnostic Code U0679

Lost Communication With Transmission Fluid Pressure Sensor/Switch A

Diagnostic Code U067A

Lost Communication With Transmission Fluid Pressure Sensor/Switch B

Diagnostic Code U067B

Lost Communication With Engine Disconnect Clutch Pressure Sensor

Diagnostic Code U067C

Lost Communication With Fan 3

Diagnostic Code U067D

Lost Communication With Fan 4

Diagnostic Code U067E

Lost Communication With Exhaust Pressure Control Valve B Sensor/Switch

Diagnostic Code U067F

Lost Communication With Barometric Pressure Sensor A

Diagnostic Code U0680

Lost Communication With Barometric Pressure Sensor B

Diagnostic Code U0681

Lost Communication With Throttle/Pedal Position Sensor/Switch D

Diagnostic Code U0682

Lost Communication With Throttle/Pedal Position Sensor/Switch E

Diagnostic Code U0683

Lost Communication With Throttle/Pedal Position Sensor/Switch F

Diagnostic Code U0684

Lost Communication With Catalyst Temperature Bank 1 Sensor 1

Diagnostic Code U0685

Lost Communication With Catalyst Temperature Bank 1 Sensor 2

Diagnostic Code U0686

Lost Communication With Catalyst Temperature Bank 2 Sensor 1

Diagnostic Code U0687

Lost Communication With Catalyst Temperature Bank 2 Sensor 2

Diagnostic Code U0688

Lost Communication With Throttle Position Sensor/Switch G

Diagnostic Code U0689

Lost Communication With Turbocharger/Supercharger B Temperature Sensor

Diagnostic Code U068A

Lost Communication With Barometric Pressure Sensor C

Diagnostic Code U068B

Lost Communication With Turbocharger/Supercharger Inlet Pressure Sensor A

Diagnostic Code U068C

Lost Communication With Turbocharger/Supercharger Inlet Pressure Sensor B

Diagnostic Code U068D

Lost Communication With EGR Temperature Sensor A

Diagnostic Code U068E

Lost Communication With EGR Temperature Sensor B

Diagnostic Code U068F

Lost Communication With EGR Temperature Sensor C

Diagnostic Code U0690

Lost Communication With EGR Temperature Sensor D

Diagnostic Code U0691

Lost Communication With Exhaust Pressure Sensor A

Diagnostic Code U0692

Lost Communication With Exhaust Pressure Sensor B

Diagnostic Code U0693

Lost Communication With Humidity Sensor

Diagnostic Code U0694

Lost Communication With Hybrid/EV Battery Pack Coolant Pump A

Diagnostic Code U0695

Lost Communication With Hybrid/EV Battery Pack Coolant Pump B

Diagnostic Code U0696

Lost Communication With Particulate Filter Pressure Sensor C

Diagnostic Code U0697

Lost Communication With Particulate Filter Pressure Sensor D

Diagnostic Code U0698

Lost Communication with Coolant Pump “E”

Diagnostic Code U0699

Lost Communication with Coolant Pump “F”

Diagnostic Code U069A

Lost Communication With Exhaust Gas Temperature Sensor Bank 1 Sensor 3

Diagnostic Code U069B

Lost Communication With Exhaust Gas Temperature Sensor Bank 1 Sensor 4

Diagnostic Code U069C

Lost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 3

Diagnostic Code U069D

Lost Communication With Exhaust Gas Temperature Sensor Bank 2 Sensor 4

Diagnostic Code U069E

Lost Communication with Coolant Heater A

Diagnostic Code U069F

Lost Communication With Exhaust Pressure Sensor C

Diagnostic Code U0901

Invalid Data from Ion Sense Module

Diagnostic Code U1000

Invalid or Missing Data for Primary Id





Network Codes (U)