DTC - Diagnostic Trouble Codes
What are DTC codes?
- The SAE J2012 standard defines a 5-digit code in which each digit represents a predetermined value. All codes are presented in the same way for ease of use. Some of these are defined by this standard, and others are reserved for manufacturers.
- The code has the following format: YXXXX (ex. P0308)
- Where Y, the first digit, represents the function of the vehicle:
|P||Motor Electronics & Transmission (Powertrain)|
- The second digit indicates the organization responsible for defining the code:
|2th digit||Organization responsible|
|0||SAE (code common to all brands)|
|1||The manufacturer of the vehicle (different code for different brands)|
- The third digit represents a specific function of the vehicle:
|0||The complete electronic system|
|1 y 2||Air and fuel control|
|4||Auxiliary emission control|
|5||Speed and idle speed control|
|6||ECU and inputs and outputs|
- The fourth and fifth digits are specifically related to the fault.
- For example, code P0308 indicates a problem in the engine electronics (P), defined by SAE (0) and common to any vehicle, related to the ignition system (3) and failure in cylinder # 8 (08 ).
- There may be fault codes stored on the ECU that do not activate the MIL.