Dtc Types - Daewoo CIELO EURO III Manual

tion is a system of diagnostic trouble codes. When a
malfunction is detected by the control module, a diag-
nostic trouble code is set and the Malfunction Indicator
Lamp (MIL) is illuminated.
Malfunction Indicator Lamp (MIL)
The Malfunction Indicator Lamp (MIL) is required by On-
Board Diagnostics (EOBD) that it illuminates under a
strict set of guide lines.
Basically, the MIL is turned on when the
engine control module (ECM) de-
tects a Diagnostic Trouble Code (DTC) that will impact
the vehicle emissions.
The MIL is under the control of the Diagnostic Execu-
tive. The MIL will be turned on if an emissions-related
diagnostic test indicates a malfunction has occurred. It
will stay on until the system or component passes the
same test, for three (four – 1.5L SOHC)
consecutive trips, with no emissions related faults.
Extinguishing the MIL
When the MIL is on, the Diagnostic Executive will turn
off the MIL after three consecutive trips that a "test
passed" has been reported for the diagnostic test that
originally caused the MIL to illuminate. Although the MIL
has been turned off, the DTC will remain in the
ECM memory (both Freeze Frame and Failure Records)
until forty (40) warm-up cycles after no faults have been
completed.
If the MIL was set by either a fuel trim or misfire-related
DTC, additional requirements must be met. In addition
to the requirements stated in the previous paragraph,
these requirements are as follows:
D The diagnostic tests that are passed must occur with
375 rpm of the rpm data stored at the time the last
test failed.
D Plus or minus ten percent of the engine load that was
stored at the time the last test failed. Similar engine
temperature conditions (warmed up or warming up)
as those stored at the time the last test failed.
Meeting these requirements ensures that the fault which
turned on the MIL has been corrected.
The MIL is on the instrument panel and has the following
functions:
D It informs the driver that a fault that affects vehicle
emission levels has occurred and that the vehicle
should be taken for service as soon as possible.
D As a system check, the MIL will come on with the key
ON and the engine not running. When the engine is
started, the MIL will turn OFF.
D When the MIL remains ON while the engine is run-
ning, or when a malfunction is suspected due to a
driveability or emissions problem, a EOBD System
Check must be performed. The procedures for these
checks are given in EOBD System Check. These
checks will expose faults which may not be detected
if other diagnostics are performed first.
DAEWOO T-154 BL2,3
ENGINE CONTROLS 1F – 419
Data Link Connector (DLC)
The provision for communicating with the control mod-
ule is the Data Link Connector (DLC). The DLC is used
to connect to a scan tool. Some common uses of the
scan tool are listed below:
D Identifying stored Diagnostic Trouble Codes (DTCs).
D Clearing DTCs.
D Performing output control tests.
D Reading serial data.

DTC TYPES

Each Diagnostic Trouble Code (DTC) is directly related
to a diagnostic test. The Diagnostic Management Sys-
tem sets DTC based on the failure of the tests during a
trip or trips. Certain tests must fail two consecutive trips
before the DTC is set. The following are the three types
of DTCs and the characteristics of those codes:
Type A
D Emissions related.
D Requests illumination of the Malfunction Indicator
Lamp (MIL) of the first trip with a fail.
D Stores a History DTC on the first trip with a fail.
D Stores a Freeze Frame (if empty).
D Stores a Fail Record.
D Updates the Fail Record each time the diagnostic test
fails.
Type B
D Emissions related.
D "Armed" after one trip with a fail.
D "Disarmed" after one trip with a pass.
D Requests illumination of the MIL on the second con-
secutive trip with a fail.
D Stores a History DTC on the second consecutive trip
with a fail. (The DTC will be armed after the first fail.)
D Stores a Freeze Frame on the second consecutive
trip with a fail (if empty.)
Type E (1.5L SOHC)
D Emissions related.
D "Armed" after two trip with a fail.
D "Disarmed" after one trip with a pass.
D Request illumination of the MIL on third consecutive
trip with a fail.
D Stores a History DTC on the third consecutive trip
with a fail (The DTC will be armed after the second
fail).
D Stores a Freeze Frame on the third consecutive trip
with a fail (if empty).
Type D (Type D non-emissions related are not utilized
on certain vehicle applications).
D Non-Emissions related.
D Does not request illumination of any lamp.