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If the trouble codes are erased when the trouble remains unresolved, the trouble code will reappear in the ECU the next
time the ECU performs the specific diagnostic test for that trouble.
If the trouble is resolved but there is a stored trouble code, sometimes the ECU will detect the resolution and clear the
trouble code or more likely, classify it as "historical" trouble.
If the trouble is resolved and the user clears the trouble codes, the trouble history will be cleared.
If the user intends to have another colleague or mechanic investigate the problem, it is not recommended for the user to
clear the trouble code since doing so may erase information helpful to others who may investigate the issue.
DTC Status
Current DTC's are trouble codes that are stored in the
ECU when both continuous and non-continuous (2 trip)
Current /Present
monitors fail. Current DTC's command the MIL On the
instant they are stored in the ECU.
History DTC's are trouble codes stored in the ECU
when continuous and non-continuous monitors (2nd
trip) fail. History DTC's set in conjunction with Current
History/Stored
DTC's and are not cleared by the ECU monitor. History
DTC's can only be cleared using the Clear DTC function
of the Scantool.
Pending codes are codes that prep themselves when
they determine a fault that engine cycle. They are
basically a preliminary investigation for your engine. To
Pending
simplify, a random malfunction can occur during the
current drive cycle but only happen for a split second.
This will cause the malfunction to throw a "pending
code".
Permanent DTC's are trouble codes that are stored in
the ECU when continuous and non-continuous
Permanent
monitors fail. Permanent DTC's are set in conjunction
with Current and History DTC's.
For Volkswagen
Active/Static means that the fault is happening at the
Active/static
moment and can/should be take care of.
It is a fault that has occurred in the past and can be
Passive/sporadic
cleared by Scantool, and user should to check if the
DTC will appear again.
⚫
READ LIVE DATA
Real-time information about various sensors is called "Live Data". Live Data includes parameter identifications (PIDs) of
the running engine such as oil pressure, temperature, engine speed, fuel oil temperature, coolant temperature, intake air
temperature, etc. Based on these parameters, we can predict directly where the problem lies, which helps to narrow the
scope of maintenance. For some vehicles, during their actual operation, the problems such as performance characteristics
or sensitivity reduction, can be evaluated using live data.
Descriptions
12
Suggestions
Current DTC's can be cleared using the
Clear DTC's function of the Scantool, or
when the ECU monitor (2 trip monitor) has
ran and completed 40 consecutive trips
without a fault.
History DTC's set in conjunction with
Current DTC's and are not cleared by the
ECU monitor. History DTC's can only be
cleared using the Clear DTC function of
the Scantool.
Typically pending codes are not to severe
but you shouldn't ignore them either, it can
be cleared using the Clear DTC's function
of the Scantool
Permanent DTC's cannot be cleared using
the Clear DTC's function on the Scantool.
Instead, Permanent DTC's are cleared
when the ECU monitor completes and
passes three consecutive trips.
The fault cannot be cleared directly by
using the Clear DTC's function of the
diagnostic tool and the internal fault of the
car must be eliminated manually
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