Standard or "Generic" Codes
Standard or "generic" codes (sometimes called "P codes") are a set of standardized diagnostic codes that turn on the check engine light and will be readable on any OBDII compatible vehicle regardless of the year and model.
Standard codes generally cover the engine and emissions equipment and will report issues such as misfires, evap leaks, failing O2 sensors, etc.
There are three types of generic/standard OBDII codes:
Pending Codes
A pending code will not turn on your check engine light and indicates that a system on your vehicle is behaving abnormally, but not so much as to mean there is an actual problem.
For example a temperature sensor might have a normal operating range of 90-110 degrees, but 80-120 degrees is considered acceptable. Once the sensor starts to read 85 degrees it is outside of the "normal" range but isn't a problem yet, so a pending code will appear.
Confirmed Codes
A confirmed code indicates that a vehicle system is experiencing an issue requiring your attention. In the temperature sensor example above, once the reading drops below 80 or above 120 degrees the vehicle would then throw a confirmed code as well.
Permanent Codes
Permanent codes are a special type introduced more recently which can not be cleared using a scan tool. If you have a permanent code the vehicle will clear it itself once the cause has been addressed and sufficient data has been gathered by driving under different conditions (idling, stop and go, highway)
Generally permanent codes cover emissions related equipment.
Enhanced or Manufacturer Codes
Enhanced codes cover all non-engine related vehicle systems, including:
ABS
Airbags
Transmission
Body Control Module (lights, turn signals, doors, etc)
HVAC
Stereo
Transfer case/4WD/AWD
etc
Enhanced codes are different for every manufacturer and are not accessible using generic scan tools, typically you will see four different types:
P Codes - Powertrain related (enhanced engine codes, transmission, etc)
C Codes - Chassis systems (ABS, suspension etc)
B Codes - Body codes (BCM, HVAC, SRS, Stereo, etc)
U Codes - Generally electrical/vehicle network related (e.g. modules no longer responding, etc)
To check what codes are supported on your vehicle, enter your year, make, and model in our FAQ!