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Model: TX-184 Article No. 4983, 04/2022
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 other four
characters, all numbers, provide
additional information on where the
DTC originated and the operating
conditions that caused it to be set.
Left side an example to illustrate
the structure of the digits.
ODB II Definitions:
Powertrain Control Module (PCM) -the OBD II terminology for the on-board computer
that controls the engine and the drive train.
Malfunction Indicator Light (MIL) -Malfunction Indicator Light (Service Engine Soon,
Check Engine) is a term used for the light on the instrument panel. It is to alert the
driver and/or the repair tech
nician that there is a problem with one or more of vehicle’s
systems and may cause emissions to exceed federal standards. If the MIL illuminates
with a steady light, it indicates that a problem has been detected and the vehicle should
be serviced as soon as possible.
Under certain conditions, the dashboard light will blink or flash. This indicates a severe
problem and flashing is intended to discourage vehicle operation. The vehicle on board
diagnostic system can not turn the MIL off until necessary repairs are completed or the
condition no longer exists.
DTC -Diagnostic Trouble Codes (DTC) these identify which section of the emission
control system has malfunctioned.
