OBD-II trouble codes
Car fault codes explained: what each code means, whether you can drive, symptoms, causes and how to diagnose it.
Codes in the guide: 1648
Codes by type
P P — powertrain
Engine, fuel, ignition, emissions and transmission.
B B — body
Body electronics: airbags, climate, seats, lighting.
C C — chassis
Chassis: ABS, stability control, steering, suspension.
U U — network
Communication between control modules over CAN and other networks.
Common codes
- P0011 Intake Camshaft Timing Over-Advanced (Bank 1)
- P0016 Crankshaft/Camshaft Position Correlation (Bank 1 Sensor A)
- P0102 Mass Air Flow Sensor Circuit Low Input
- P0113 Intake Air Temperature Sensor Circuit High Input
- P0128 Coolant Temperature Below Thermostat Regulating Temperature
- P0171 System Too Lean (Bank 1)
- P0300 Random or Multiple Cylinder Misfire Detected
- P0301 Cylinder 1 Misfire Detected
- P0335 Crankshaft Position Sensor "A" Circuit Malfunction
- P0401 Exhaust Gas Recirculation (EGR) Flow Insufficient
- P0420 Catalyst System Efficiency Below Threshold (Bank 1)
- P0442 Small Leak in the Evaporative Emission (EVAP) System
- P0455 EVAP System Large Leak Detected
- P0500 Vehicle Speed Sensor Malfunction
- P0700 Transmission Control System Malfunction
- U0100 Lost Communication with ECM/PCM
Codes by system
- Fuel and air · 561
- Engine · 337
- Emissions · 232
- Airbags · 151
- Transmission · 91
- CAN network · 80
- Ignition · 67
- ABS and brakes · 40
- Cooling · 36
- Electrical and sensors · 28
- Other · 7
- Charging and battery · 7
- Hybrid and EV · 4
- Climate and heating · 3
- Body and comfort · 3
- Steering and suspension · 1
Brand-specific meanings
- Alfa Romeo · 3
- Chevrolet · 12
- Chrysler · 15
- Dodge · 8
- Ford · 193
- Genesis · 1
- GM · 3
- Honda · 8
- Hyundai · 16
- Jaguar · 8
- Jeep · 5
- Kia · 8
- Land Rover · 18
- Lexus · 8
- Mazda · 15
- Mercedes-Benz · 5
- MINI · 13
- Mitsubishi · 3
- Nissan · 1
- Opel · 4
- Porsche · 3
- PSA · 4
- Subaru · 6
- Suzuki · 5
- Toyota · 3
- VAG · 8
How to use this guide
A diagnostic trouble code (DTC) is stored by a control module when a sensor reading or a component goes out of its normal range. Codes are read with a scan tool through the OBD-II port under the dashboard.
The first letter shows the system: P for powertrain, B for body, C for chassis, U for network. A 0 as the second character means a generic SAE code, 1 means a manufacturer code.
A code tells you where to look, not which part failed. Start with the simple checks on the code page, and after a repair clear the code and see whether it comes back.