MIL Operation
The Malfunction Indicator Lamp (MIL) is located on the instrument panel
(CHECK ENGINE) or (SERVICE ENGINE SOON). The MIL performs the following functions:
| • | It informs the driver that a problem has occurred and that the
vehicle should be taken for service as soon as possible. |
| • | As a bulb check and system check, the MIL will illuminate with
the ignition switch ON and the engine not running. when the engine is started,
the MIL will turn OFF. If the MIL remains ON, the self-diagnostic system has
detected a problem. If the problem goes away, the MIL will turn OFF in most
cases, but a diagnostic trouble code will remain stored. |
| • | If the MIL is illuminated, then the engine stalls, the MIL will
remain Illuminated so long as the ignition switch is ON. |
| • | Now, if the MIL is not
illuminated and
the engine stalls, the MIL will not illuminate until the ignition switch is
cycled OFF, then ON. |
Perform the Powertrain On-Board Diagnostic System Check first, when
the following conditions are present:
| • | When the MIL does not turn ON when the the ignition switch is
turned to the RUN position |
| • | When the MIL remains ON while the engine is running |
| • | When you suspect a driveability problem |
The PCM controlled lamps are intended to alert the driver
to an operating condition which may require immediate attention. The instrument
panel indicators, ignition 1 feed, powers the PCM controlled lamps.
Check Gauges Lamp
The PCM commands the Check Gauges lamp ON under the following conditions:
| • | When the engine speed is greater than 1200 rpm and system
voltage falls below 10 volts for longer than 10 seconds. The
PCM commands the Check Gauges lamp OFF when system voltage rises to above
12 volts. |
| • | When the generator control circuit (L terminal) remains
low for longer than 10 seconds. |
| • | When the engine speed is below 2000 rpm and the generator
PWM control circuit (F terminal) duty cycle falls below 5% and remains
below 15% for longer than 20 seconds. |
| • | When the engine speed is above 4000 rpm and the generator
PWM control circuit (F terminal) duty cycle increases to above 95% and remains
above 85% for longer than 20 seconds. |
