Car Fault Codes

We provide information about what the fault codes of cars mean. We offer solutions for these fault codes you encounter.

P008B

Low Pressure Fuel System Pressure - Too High

P008A

Low Pressure Fuel System Pressure - Too Low

P0089

Fuel Pressure Regulator 1 Performance

P0088

Fuel Rail/System Pressure - Too High

P0087

Fuel Rail/System Pressure - Too Low

P0086

Exhaust Valve Control Solenoid Circuit High (Bank 2)

P0085

Exhaust Valve Control Solenoid Circuit Low (Bank 2)

P0084

Exhaust Valve Control Solenoid Circuit (Bank 2)

P0083

Intake Valve Control Solenoid Circuit High (Bank 2)

P0082

Intake Valve Control Solenoid Circuit Low (Bank 2)

P0081

Intake valve Control Solenoid Circuit (Bank 2)

P0080

Exhaust Valve Control Solenoid Circuit High (Bank 1)

P007F

Charge Air Cooler Temperature Sensor Bank1/Bank2 Correlation

P007E

Charge Air Cooler Temperature Sensor Circuit Intermittent/Erratic Bank 1

P007D

Charge Air Cooler Temperature Sensor Circuit High Bank 1

P007C

Charge Air Cooler Temperature Sensor Circuit Low Bank 1

P007B

Charge Air Cooler Temperature Sensor Circuit Range/Performance Bank 1

P007A

Charge Air Cooler Temperature Sensor Circuit Bank 1

P0079

Exhaust Valve Control Solenoid Circuit Low (Bank 1)

P0078

Exhaust Valve Control Solenoid Circuit (Bank 1)

P0077

Intake Valve Control Solenoid Circuit High (Bank 1)

P0076

Intake Valve Control Solenoid Circuit Low (Bank 1)

P0075

Intake Valve Control Solenoid Circuit (Bank 1)

P0074

Ambient Air Temperature Sensor Circuit Intermittent

P0073

Ambient Air Temperature Sensor Circuit High Input

P0072

Ambient Air Temperature Sensor Circuit Low Input

P0071

Ambient Air Temperature Sensor Range/Performance

P0070

Ambient Air Temperature Sensor Circuit

P006F

Turbocharger/Supercharger Boost Control "A" Supply Voltage Circuit High

P006E

Turbocharger/Supercharger Boost Control "A" Supply Voltage Circuit Low

P006D

Barometric Pressure - Turbocharger/Supercharger Inlet Pressure Correlation

P006C

MAP - Turbocharger/Supercharger Inlet Pressure Correlation

P006B

MAP - Exhaust Pressure Correlation

P006A

MAP - Mass or Volume Air Flow Correlation Bank 1

P0069

Manifold Absolute Pressure - Barometric Pressure Correlation

P0068

MAP/MAF - Throttle Position Correlation

P0067

Air Assisted Injector Control Circuit High

P0066

Air Assisted Injector Control Circuit or Circuit Low

P0065

Air Assisted Injector Control Range/Performance

P0064

HO2S Heater Control Circuit High (Bank 2 Sensor 3)

P0063

HO2S Heater Control Circuit Low (Bank 2 Sensor 3)

P0062

HO2S Heater Control Circuit (Bank 2 Sensor 3)

P0061

HO2S Heater Resistance (Bank 2, Sensor 3)

P0060

HO2S Heater Resistance (Bank 2, Sensor 2)

P005F

Turbocharger/Supercharger Boost Control B Supply Voltage Circuit High

P005E

Turbocharger/Supercharger Boost Control B Supply Voltage Circuit Low

P005D

B Camshaft Profile Control Stuck On Bank 2

P005C

B Camshaft Profile Control Performance/Stuck Off Bank 2

P005B

B Camshaft Profile Control Stuck On Bank 1

P005A

B Camshaft Profile Control Performance/Stuck Off Bank 1

P0059

HO2S Heater Resistance (Bank 2, Sensor 1)

P0058

HO2S Heater Control Circuit High (Bank 2 Sensor 2)

P0057

HO2S Heater Control Circuit Low (Bank 2 Sensor 2)

P0056

HO2S Heater Control Circuit (Bank 2 Sensor 2)

P0055

HO2S Heater Resistance (Bank 1, Sensor 3)

P0054

HO2S Heater Resistance (Bank 1, Sensor 2)

P0053

HO2S Heater Resistance (Bank 1, Sensor 1)

P0052

HO2S Heater Control Circuit High (Bank 2 Sensor 1)

P0051

HO2S Heater Control Circuit Low (Bank 2 Sensor 1)

P0050

HO2S Heater Control Circuit (Bank 2 Sensor 1)

P004F

Turbocharger/Supercharger Boost Control "B" Circuit Intermittent/Erratic

P004E

Turbocharger/Supercharger Boost Control A Circuit Intermittent/Erratic

P004D

Turbocharger/Supercharger Boost Control B Circuit High

P004C

Turbocharger/Supercharger Boost Control B Circuit Low

P004B

Turbocharger/Supercharger Boost Control B Circuit Range/Performance

P004A

Turbocharger/Supercharger Boost Control "B" Circuit/Open

P0049

Turbocharger/Supercharger Turbine Overspeed

P0048

Turbocharger/Supercharger Boost Control "A" Circuit High

P0047

Turbocharger/Supercharger Boost Control "A" Circuit Low

P0046

Turbocharger/Supercharger Boost Control "A" Circuit Range/Performance

P0045

Turbocharger/Supercharger Boost Control "A" Circuit/Open

P0044

HO2S Heater Control Circuit High (Bank 1 Sensor 3)

P0043

HO2S Heater Control Circuit Low (Bank 1 Sensor 3)

P0042

HO2S Heater Control Circuit (Bank 1 Sensor 3)

P0041

Downstream Oxygen Sensors Swapped From Bank To Bank

P0040

Upstream Oxygen Sensors Swapped From Bank To Bank

P003F

A Camshaft Profile Control Stuck On Bank 2

P003E

A Camshaft Profile Control Performance/Stuck Off Bank 2

P003D

A Camshaft Profile Control Stuck On Bank 1

P003C

A Camshaft Profile Control Performance/Stuck Off Bank 1

P003B

Turbocharger/Supercharger Boost Control "B" Position Exceeded Learning Limit

P003A

Turbocharger/Supercharger Boost Control "A" Position Exceeded Learning Limit

P0039

Turbo/Super Charger Bypass Valve Control Circuit Range/Performance

P0038

HO2S Heater Control Circuit High (Bank 1 Sensor 2)

P0037

HO2S Heater Control Circuit Low (Bank 1 Sensor 2)

P0036

HO2S Heater Control Circuit (Bank 1 Sensor 2)

P0035

Turbo Charger Bypass Valve Control Circuit High

P0034

Turbo Charger Bypass Valve Control Circuit Low

P0033

Turbo Charger Bypass Valve Control Circuit

P0032

HO2S Heater Control Circuit High (Bank 1 Sensor 1)

P0031

HO2S Heater Control Circuit Low (Bank 1 Sensor 1)

P0030

HO2S Heater Control Circuit (Bank 1 Sensor 1)

P002F

B Camshaft Profile Control Circuit High Bank 2

P002E

B Camshaft Profile Control Circuit Low Bank 2

P002D

B Camshaft Profile Control Circuit/Open Bank 2

P002C

B Camshaft Profile Control Circuit High Bank 1

P002B

B Camshaft Profile Control Circuit Low Bank 1

P002A

B Camshaft Profile Control Circuit/Open Bank 1

P0029

Exhaust Valve Control Solenoid Circuit Range/Performance Bank 2

P0028

Intake valve Control Solenoid Circuit Range/Performance Bank 2

P0027

Exhaust Valve Control solenoid Circuit Range/Performance Bank 1

P0026

Intake Valve Control Solenoid Circuit Range/Performance Bank 1

P0025

B Camshaft Position - Timing Over-Retarded (Bank 2)

P0024

B Camshaft Position - Timing Over-Advanced or System Performance (Bank 2)

P0023

B Camshaft Position - Actuator Circuit (Bank 2)

P0022

A Camshaft Position - Timing Over-Retarded (Bank 2)

P0021

A Camshaft Position - Timing Over-Advanced or System Performance (Bank 2)

P0020

A Camshaft Position Actuator Circuit (Bank 2)

P001F

A Camshaft Profile Control Circuit High Bank 2

P001E

A Camshaft Profile Control Circuit Low Bank 2

P001D

A Camshaft Profile Control Circuit/Open Bank 2

P001C

A Camshaft Profile Control Circuit High Bank 1

P001B

"A" Camshaft Profile Control Circuit Low Bank 1

P001A

"A" Camshaft Profile Control Circuit/Open Bank 1

P0019

Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor B)

P0018

Crankshaft Position - Camshaft Position Correlation (Bank 2 Sensor A)

P0017

Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor B)

P0016

Crankshaft Position - Camshaft Position Correlation (Bank 1 Sensor A)

P0015

"B" Camshaft Position -Timing Over-Retarded (Bank 1)

P0014

"B" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)

P0013

"B" Camshaft Position - Actuator Circuit (Bank 1)

P0012

"A" Camshaft Position - Timing Over-Retarded (Bank 1)

P0011

"A" Camshaft Position - Timing Over-Advanced or System Performance (Bank 1)

P0010

"A" Camshaft Position Actuator Circuit (Bank 1)

P000F

Fuel System Over Pressure Relief Valve Activated

P000E

Fuel Volume Regulator Control Exceeded Learning Limit

P000D

"B" Camshaft Position Slow Response Bank 2

P000C

"A" Camshaft Position Slow Response Bank 2

P000B

"B" Camshaft Position Slow Response Bank 1

P000A

"A" Camshaft Position Slow Response Bank 1

P0009

Engine Position System Performance Bank 2

P0008

Engine Positions System Performance Bank 1

P0007

Fuel Shutoff Valve "A" Control Circuit High

P0006

Fuel Shutoff Valve "A" Control Circuit Low

P0005

Fuel Shutoff Valve "A" Control Circuit/Open

P0004

Fuel Volume Regulator Control Circuit High

P0003

Fuel Volume Regulator Control Circuit Low

P0002

Fuel Volume Regulator Control Circuit Range/Performance

P0001

Fuel Volume Regulator Control Circuit/Open

P02FA

Diesel Intake Air Flow Position Sensor Minimum/Maximum Stop Performance

P02F9

Cylinder 12 Injector Circuit Range/Performance

P02F8

Cylinder 11 Injector Circuit Range/Performance

P02F7

Cylinder 10 Injector Circuit Range/Performance

P02F6

Cylinder 9 Injector Circuit Range/Performance

P02F5

Cylinder 8 Injector Circuit Range/Performance

P02F4

Cylinder 7 Injector Circuit Range/Performance

P02F3

Cylinder 6 Injector Circuit Range/Performance

P02F2

Cylinder 5 Injector Circuit Range/Performance

P02F1

Cylinder 4 Injector Circuit Range/Performance

P02F0

Cylinder 3 Injector Circuit Range/Performance

P02EF

Cylinder 2 Injector Circuit Range/Performance

P02EE

Cylinder 1 Injector Circuit Range/Performance

P02ED

Diesel Intake Air Flow Control System - Low Air Flow Detected

P02EC

Diesel Intake Air Flow Control System - High Air Flow Detected

P02EB

Diesel Intake Air Flow Control Motor Current Range/Performance

P02EA

Diesel Intake Air Flow Position Sensor Circuit Intermittent/Erratic

P02E9

Diesel Intake Air Flow Position Sensor Circuit High

P02E8

Diesel Intake Air Flow Position Sensor Circuit Low

P02E7

Diesel Intake Air Flow Position Sensor Circuit Range/Performance

P02E6

Diesel Intake Air Flow Position Sensor Circuit

P02E5

Diesel Intake Air Flow Control Stuck Closed

P02E4

Diesel Intake Air Flow Control Stuck Open

P02E3

Diesel Intake Air Flow Control Circuit High

P02E2

Diesel Intake Air Flow Control Circuit Low

P02E1

Diesel Intake Air Flow Control Performance

P02E0

Diesel Intake Air Flow Control Circuit/Open

P02DF

Cylinder 10 Fuel Injector Offset Learning At Max Limit

P02DE

Cylinder 10 Fuel Injector Offset Learning At Min Limit

P02DD

Cylinder 9 Fuel Injector Offset Learning At Max Limit

P02DC

Cylinder 9 Fuel Injector Offset Learning At Min Limit

P02DB

Cylinder 8 Fuel Injector Offset Learning At Max Limit

P02DA

Cylinder 8 Fuel Injector Offset Learning At Min Limit

P02D9

Cylinder 7 Fuel Injector Offset Learning At Max Limit

P02D8

Cylinder 7 Fuel Injector Offset Learning At Min Limit

P02D7

Cylinder 6 Fuel Injector Offset Learning At Max Limit

P02D6

Cylinder 6 Fuel Injector Offset Learning At Min Limit

P02D5

Cylinder 5 Fuel Injector Offset Learning At Max Limit

P02D4

Cylinder 5 Fuel Injector Offset Learning At Min Limit

P02D3

Cylinder 4 Fuel Injector Offset Learning At Max Limit

P02D2

Cylinder 4 Fuel Injector Offset Learning At Min Limit

P02D1

Cylinder 3 Fuel Injector Offset Learning At Max Limit

P02D0

Cylinder 3 Fuel Injector Offset Learning At Min Limit

P02CF

Cylinder 2 Fuel Injector Offset Learning At Max Limit

P02CE

Cylinder 2 Fuel Injector Offset Learning At Min Limit

P02CD

Cylinder 1 Fuel Injector Offset Learning At Max Limit

P02CC

Cylinder 1 Fuel Injector Offset Learning At Min Limit

P02CB

Turbocharger/Supercharger B Underboost Condition

P02CA

Turbocharger / Supercharger "B" Overboost Condition

P02C9

Cylinder 12 Injector Leaking

P02C8

Cylinder 12 Injector Restricted

P02C7

Cylinder 12 Fuel Trim at Min Limit

P02C6

Cylinder 12 Fuel Trim at Max Limit

P02C5

Cylinder 11 Injector Leaking

P02C4

Cylinder 11 Injector Restricted

P02C3

Cylinder 11 Fuel Trim at Min Limit

P02C2

Cylinder 11 Fuel Trim at Max Limit

P02C1

Cylinder 10 Injector Leaking

P02C0

Cylinder 10 Injector Restricted

P02BF

Cylinder 10 Fuel Trim at Min Limit

P02BE

Cylinder 10 Fuel Trim at Max Limit

P02BD

Cylinder 9 Injector Leaking

P02BC

Cylinder 9 Injector Restricted

P02BB

Cylinder 9 Fuel Trim at Min Limit

P02BA

Cylinder 9 Fuel Trim at Max Limit

P02B9

Cylinder 8 Injector Leaking

P02B8

Cylinder 8 Injector Restricted

P02B7

Cylinder 8 Fuel Trim at Min Limit

P02B6

Cylinder 8 Fuel Trim at Max Limit

P02B5

Cylinder 7 Injector Leaking

P02B4

Cylinder 7 Injector Restricted

P02B3

Cylinder 7 Fuel Trim at Min Limit

P02B2

Cylinder 7 Fuel Trim at Max Limit

P02B1

Cylinder 6 Injector Leaking

P02B0

Cylinder 6 Injector Restricted

P02AF

Cylinder 6 Fuel Trim at Min Limit

P02AE

Cylinder 6 Fuel Trim at Max Limit

P02AD

Cylinder 5 Injector Leaking

P02AC

Cylinder 5 Injector Restricted

P02AB

Cylinder 5 Fuel Trim at Min Limit

P02AA

Cylinder 5 Fuel Trim at Max Limit

P02A9

Cylinder 4 Injector Leaking

P02A8

Cylinder 4 Injector Restricted

P02A7

Cylinder 4 Fuel Trim at Min Limit

P02A6

Cylinder 4 Fuel Trim at Max Limit

P02A5

Cylinder 3 Injector Leaking

P02A4

Cylinder 3 Injector Restricted

P02A3

Cylinder 3 Fuel Trim at Min Limit

P02A2

Cylinder 3 Fuel Trim at Max Limit

P02A1

Cylinder 2 Injector Leaking

P02A0

Cylinder 2 Injector Restricted

P029F

Cylinder 2 Fuel Trim at Min Limit

P029E

Cylinder 2 Fuel Trim at Max Limit

P029D

Cylinder 1 Injector Leaking

P029C

Cylinder 1 Injector Restricted

P029B

Cylinder 1 Fuel Trim at Min Limit

P029A

Cylinder 1 Fuel Trim at Max Limit

P0299

Turbocharger/Supercharger A Underboost Condition

P0298

Engine Oil Over Temperature Condition

P0297

Vehicle Overspeed Condition

P0296

Cylinder 12 Contribution/Balance

P0295

Cylinder #12 Injector Circuit High

P0294

Cylinder #12 Injector Circuit Low

P0293

Cylinder 11 Contribution/Balance

P0292

Cylinder 11 Injector Circuit High

P0291

Cylinder 11 Injector Circuit Low

P0290

Cylinder 10 Contribution/Balance

P0289

Cylinder #10 Injector Circuit High

P0288

Cylinder #10 Injector Circuit Low

P0287

Cylinder 9 Contribution/Balance

P0286

Cylinder #9 Injector Circuit High

P0285

Cylinder #9 Injector Circuit Low

P0284

Cylinder 8 Contribution/Balance

P0283

Cylinder #8 Injector Circuit High

P0282

Cylinder #8 Injector Circuit Low

P0281

Cylinder 7 Contribution/Balance

P0280

Cylinder #7 Injector Circuit High

P0279

Cylinder #7 Injector Circuit Low

P0278

Cylinder 6 Contribution/Balance

P0277

Cylinder #6 Injector Circuit High

P0276

Cylinder #6 Injector Circuit Low

P0275

Cylinder 5 Contribution/Balance

P0274

Cylinder #5 Injector Circuit High

P0273

Cylinder #5 Injector Circuit Low

P0272

Cylinder 4 Contribution/Balance

P0271

Cylinder #4 Injector Circuit High

P0270

Cylinder #4 Injector Circuit Low

P0269

Cylinder 3 Contribution/Balance

P0268

Cylinder #3 Injector Circuit High

P0267

Cylinder #3 Injector Circuit Low

P0266

Cylinder 2 Contribution/Balance

P0265

Cylinder #2 Injector Circuit High

P0264

Cylinder #2 Injector Circuit Low

P0263

Cylinder 1 Contribution/Balance

P0262

Cylinder #1 Injector Circuit High

P0261

Cylinder #1 Injector Circuit Low

P0260

Injection Pump Fuel Metering Control B Intermittent (Cam/Rotor/Injector)

P025D

Fuel Pump Module Control High

P025C

Fuel Pump Module Control Low

P025B

Fuel Pump Module Control Range/Performance

P025A

Fuel Pump Module Control Circuit/Open

P0259

Injection Pump Fuel Metering Control B High (Cam/Rotor/Injector)

P0258

Injection Pump Fuel Metering Control B Low (Cam/Rotor/Injector)

P0257

Injection Pump Fuel Metering Control B Range/Performance (Cam/Rotor/Injector)

P0256

Injection Pump Fuel Metering Control B Malfunction (Cam/Rotor/Injector)

P0255

Injection Pump Fuel Metering Control B Intermittent (Cam/Rotor/Injector)

P0254

Injection Pump Fuel Metering Control A High (Cam/Rotor/Injector)

P0212

Cylinder 12 Injector Circuit Malfunction

P0253

Injection Pump Fuel Metering Control A Low (Cam/Rotor/Injector)

P0252

Injection Pump Fuel Metering Control A Range/Performance (Cam/Rotor/Injector)

P0251

Injection Pump Fuel Metering Control A Malfunction (Cam/Rotor/Injector)

P0250

Turbocharger Wastegate Solenoid B High

P024F

Charge Air Cooler Bypass Position Sensor A Circuit High

P024E

Charge Air Cooler Bypass Position Sensor A Circuit Low

P024D

Charge Air Cooler Bypass Position Sensor A Circuit Range/Performance

P024C

Charge Air Cooler Bypass Position Sensor A Circuit

P024A

Charge Air Cooler Bypass Control A Circuit Range/Performance

P0249

Turbocharger Wastegate Solenoid B Low

P0248

Turbocharger Wastegate Solenoid B Range/Performance

P0247

Turbocharger Wastegate Solenoid B Malfunction

P0246

Turbocharger Wastegate Solenoid A High

P0245

Turbocharger Wastegate Solenoid A Low

P0244

Turbocharger Wastegate Solenoid A Range/Performance

P0243

Turbocharger Wastegate Solenoid A Malfunction

P0242

Turbocharger/Supercharger Boost Sensor "B" Circuit High Input

P0241

Generic: Turbocharger/Supercharger Boost Sensor "B" Circuit Low

P0240

Turbocharger Boost Sensor B Range/Performance

P023F

Fuel Pump Secondary Circuit/Open

P023E

Manifold Absolute Pressure - Turbocharger/Supercharger Boost Sensor B Correlation

P023D

Manifold Absolute Pressure - Turbocharger/Supercharger Boost Sensor A Correlation

P023C

Charge Air Cooler Coolant Pump Control Circuit High

P023B

Charge Air Cooler Coolant Pump Control Circuit Low

P023A

Charge Air Cooler Coolant Pump Control Circuit Open

P0239

Turbocharger Boost Sensor B Circuit Malfunction

P0238

Turbocharger/Supercharger Boost Sensor "A" Circuit High Input

P0237

Turbocharger/Supercharger Boost Sensor "A" Circuit Low

P0236

Turbocharger Boost Sensor A Range/Performance

P0235

Turbocharger Boost Sensor A Circuit Malfunction

P0234

Turbocharger / Supercharger "A" Overboost Condition

P0233

Fuel Pump Secondary Circuit Intermittent

P0232

Fuel Pump Secondary (Feedback) Circuit High Voltage

P0231

Fuel Pump Secondary (Feedback) Circuit Low Voltage

P0230

Fuel Pump Primary (Control) Circuit Malfunction

P022F

Charge Air Cooler Bypass Control B Circuit High

P022E

Charge Air Cooler Bypass Control B Circuit Low

P022D

Charge Air Cooler Bypass Control B Circuit Open

P022C

Charge Air Cooler Bypass Control A Circuit High

P022B

Turbocharger Boost Control "B" Circuit Range/Performance.

P022A

Charge Air Cooler Bypass Control A Circuit Open

P0229

Throttle Position Sensor/Switch C Circuit Intermittent

P0228

Throttle Position Sensor/Switch C Circuit High Input

P0227

Throttle Position Sensor/Switch C Circuit Low Input

P0226

Throttle Position Sensor/Switch C Circuit Range/Performance

P0225

Throttle Position Sensor/Switch (TPS) C Circuit Malfunction

P0224

Throttle Position Sensor/Switch B Circuit Intermittent

P0223

Throttle Position Sensor/Switch B Circuit High Input

P0222

Throttle Position Sensor/Switch B Circuit Low Input

P0221

Throttle Position Sensor/Switch B Circuit Range/Performance

P0220

Throttle Position Sensor/Switch (TPS) B Circuit Malfunction

P021F

Cylinder 12 Injection Timing

P021E

Cylinder 11 Injection Timing

P021D

Cylinder 10 Injection Timing

P021C

Cylinder 9 Injection Timing

P021B

Cylinder 8 Injection Timing

P021A

Cylinder 7 Injection Timing

P0219

Engine Overspeed Condition

P0218

Transmission Over Temperature Condition

P0217

Engine Overtemp Condition

P0216

Injection Timing Control Circuit Malfunction

P0215

Engine Shutoff Solenoid Malfunction

P0214

Cold Start Injector 2 Malfunction

P0211

Cylinder 11 Injector Circuit Malfunction

P0210

Cylinder 10 Injector Circuit Malfunction

P020F

Cylinder 6 Injection Timing

P020E

Cylinder 5 Injection Timing

P020D

Cylinder 4 Injection Timing

P020C

Cylinder 3 Injection Timing

P020B

Cylinder 2 Injection Timing

P020A

Cylinder 1 Injection Timing

P0209

Cylinder 9 Injector Circuit Malfunction

P0208

Cylinder 8 Injector Circuit Malfunction

P0207

Cylinder 7 Injector Circuit Malfunction

P0206

Cylinder 6 Injector Circuit Malfunction

P0205

Cylinder 5 Injector Circuit Malfunction

P0204

Cylinder 4 Injector Circuit Malfunction

P0203

Cylinder 3 Injector Circuit Malfunction

P0202

Cylinder 2 Injector Circuit Malfunction

P0201

Cylinder 1 Injector Circuit Malfunction

P0200

Fuel Injector Circuit Malfunction