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CRP12X Premium Series User's Manual
2.2 Diagnostic Trouble Codes (DTCs)
OBD II Diagnostic Trouble Codes are codes that are stored by the on-board
computer diagnostic system in response to a problem found in the vehicle. These
codes identify a particular problem area and are intended to provide you with a
guide as to where a fault might be occurring within a vehicle. OBD II Diagnostic
Trouble Codes consist of a five-digit alphanumeric code. The first character,
a letter, identifies which control system sets the code. The second character,
a number, 0-3; other three characters, a hex character, 0-9 or A-F provide
additional information on where the DTC originated and the operating conditions
that caused it to set. Here below is an example to illustrate the structure of the
digits:
Figure 2-1
2.3 Location of the Data Link Connector (DLC)
The DLC (Data Link Connector or Diagnostic Link Connector) is typically a 16-
pin connector where diagnostic code readers interface with the vehicle’s on-
