GM and several other manufacturers have added additional information to the 5 digit codes. These are not “codes” but are “Symptom categories”. The DTC symptom is made up of an additional 2 digit code that is place after the 5 digit code (usually a space between the two codes) The first digit following the DTC indicates the symptom category, while the second digit refers to the subsystem or a more in depth information about the symptom. There are 16 possible symptom categories available for 0 to 9 and A to F. Currently there are only 8 categories in use, 0 through 7
My question is where can I get a comprehensive list of these symptom categories and subsystems?
Internet is not of much use to me!
I can find Symptom categories 0 to 7 online.
8 to F are reserved for future use. Have these been allocated?