ENGINE <NON-TURBO>
-
Control Svstem
1-31
DIAGNOSTIC SYSTEM
id
MALFUNCTION INDICATOR LAMP (MIL)
The PCM provides the ground path for the malfunc-
tion indicator lamp (Check Engine light in the gauge
cluster on the instrument panel). The lamp comes
on each time the ignition key is turned ON and
stays on for a 3 seconds bulb test.
The MIL lamp stays on continuously, when the PCM
has entered a Limp-in mode or identified a failed
emission component. During Limp-in Mode, the
PCM attempts to keep the system operational. The
malfunction indicator lamp signals the need for im-
mediate service. In limp-in mode, the PCM compen-
sates for the failure of certain components that send
incorrect signals by substituting inputs from other
sensors.
GENERAL INFORMATION
The diagnostic system for vehicles with a manual
transaxle conforms to OBD-II, where the one for
vehicles with an automatic transaxle conforms to
OBD-I.
OBD II has been developed to allow to meet the
requirements of the Federal Clean Air Act and
California Air Resources Board (CARB) legislation.
L
It is impractical (and very expensive) to provide
every vehicle on the road with the equipment neces-
sary to measure emissions of carbon monoxide
(CO), hydrocarbons (HC) and oxides of nitrogen
(NOx).
Instead, the proven emissions control de-
vices available for these vehicles are checked for
proper operation.
MIL ILLUMINATION:
WlAK31AA
If the PCM detects active engine misfire severe
enough to cause catalyst damage, it flashes the
malfunction indicator lamp (Check Engine light). ,At
the same time the PCM also sets a diagnostic trouble
code. <vehicles with manual transaxle>
The malfunction indicator lamp can also display
diagnostic trouble codes. Cycle the ignition switch
on, off, on, off, on, within five seconds and the PCM
displays any diagnostic trouble codes stored in
memory.
The diagnostic trouble codes can also be read by
the scan tool.
U71AK32AA
NOTE
When monitoring the misfire and fuel system, if
trouble is detected, the MIL will light until the comple-
tion of the next operation cycle (trip) following the
cycle where the trouble is detected. In addition,
if the detected trouble may cause damage to the
catalytic converter, the MIL will light immediately.
However, if the trouble is not detected in the
succeeding trip under almost the same driving condi-
tion, MIL should go out. And if the same trouble
will not be detected within 80 trips following the
trip where the trouble is detected, the diagnostic
trouble code will be erased.
. FAULT ON TWO SUCCESSIVE TRIPS
-
. (MIL ON) NO FAULT ON THREE
SUCCESSIVE TRIPS
b
MIL ON
MIL OFF
L
FAULT CODE STORAGE:
. FAULT ON TWO SUCCESSIVE TRIPS
h
. (DTC) NO FAULT ON 40-80
SUCCESSIVE TRIPS
b
DIAGNOSTIC TROUBLE
CODE STORED
DIAGNOSTIC TROUBLE
CODE ERASED
To Next Page
Loading...
Need help?
General
