Page 345 - Mechanic Diesel - TT
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MECHANIC DIESEL - CITS
OBD2 diagnostic trouble codes are made up of five characters:
The 1st character is a letter (B, C, P or U). It identifies the “main system” where the fault occurred (Body, Chassis,
Powertrain, or Network). The 2nd character is a numeric digit (0 thru 3). It identifies the “type” of code (Generic
or Manufacturer-Specific). Generic DTCs are codes that are used by all vehicle manufacturers. The standards for
generic DTCs, as well as their definitions, are set by the Society of Automotive Engineers (SAE).
Manufacturer-Specific DTCs are codes that are controlled by the vehicle manufacturers. The Federal Government
does not require vehicle manufacturers to go beyond the standardized generic DTCs in order to comply with the
new OBD2 emissions standards. However, manufacturers are free to expand beyond the standardized codes to
make their systems easier to diagnose.
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CITS : Automotive - Mechanic Diesel - Lesson 104 - 107
