文档介绍：On Board Diagnostic (OBD) Página 1 de 22
01-1
On Board Diagnostic (OBD)
On Board Diagnostic (OBD) features
The Motronic Engine Control Module (ECM)
-J220- is equipped with a DTC memory.
If Diagnostic Trouble Codes (DTCs) occur in
the sensors ponents being
monitored, they will be stored in the DTC
memory together with an indication of the
type of malfunction.
After evaluating the information the Motronic
Engine Control Module (ECM) -J220-
decides between the different Diagnostic
Trouble Codes (DTCs) DTC table from
Page 01-30 and stores these until the
contents of the DTC memory are erased.
Diagnostic Trouble Codes (DTCs) which
only occur sporadically will have the
addendum "sporadic fault" on the print out.
These Diagnostic Trouble Codes (DTCs) will
be indicated on the display by the
addendum "/SP". The cause of sporadic
Diagnostic Trouble Codes (DTCs) can be
. a loose terminal or a brief open circuit. If
a "sporadic malfunction" does not occur
again within 40 warm-up phases (engine
start below 50 C coolant temperature -
switched off above 72 C), it will be erased
from the DTC memory.
The Diagnostic Trouble Codes (DTCs)
stored can be read-out with the VAG 1551
scan tool, the vehicle system tester VAG
1552 or the vehicle diagnostic, testing and
information system VAS 5051 Page 01-
23 .
http://ebahn./vw/servlet/Display?action=Goto&type=repair&id=... 12/2/2005
On Board Diagnostic (OBD) Página 2 de 22
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The DTC memory must be erased after the
malfunction(s) have been repaired Page
01-23 and the readiness code must be
regenerated Page 01-149 .
All Motronic Engine Control Module (ECM) -
J220- learned values will be erased when
the Motronic Engine Control Module (ECM)
-J220- connector is pulled off or the battery
is disconnected. However the contents of
the DTC memory are retained. When the
engine is subsequently started the i