FAQ: OBD2 Codes Explained
OBD-II codes consist of a number of parts. Here is a sample OBD2 code:
Here is a breakdown of what each digit of the code means:
First Character - System
The first character identifies identifies the system related to the trouble code.
- P = Powertrain
- B = Body
- C = Chassis
- U = Undefined
Second Digit - Code Type
The second digit identifies whether the code is a generic code (same on all OBD-II equpped vehicles), or a manufacturer specific code.
- 0 = Generic (this is the digit zero -- not the letter "O")
- 1 = Enhanced (manufacturer specific)
Third Digit - Sub-System
The third digit denotes the type of sub-system that pertains to the code
- 1 = Emission Management (Fuel or Air)
- 2 = Injector Circuit (Fuel or Air)
- 3 = Ignition or Misfire
- 4 = Emission Control
- 5 = Vehicle Speed & Idle Control
- 6 = Computer & Output Circuit
- 7 = Transmission
- 8 = Transmission
- 9 = SAE Reserved
- 0 = SAE Reserved
Fourth and Fifth Digits
These digits, along with the others, are variable, and relate to a particular problem. For example,a P0171 code means P0171 - System Too Lean (Bank 1). To lookup your particular code, visit our OBD Trouble Codes section.
NOTE: This information is presented for information purposes only. It is not intended as repair advice and we are not responsible for any actions you take on any vehicle. All information on this site is copyright protected.