Chrysler 1991 - AIR INTAKE HEATER RELAYS-ENGINE CONTROLLER OUTPUT; AIR INTAKE HEATER; PREHEAT CYCLE

14 - 4 FUEL SYSTEM
Fig. 8 Vehicle Distance Sensor
ignition key is put in the ON position. It also moni-
tors the input at the end of the intake heater post-
heat cycle.
The engine controller turns the Water-in-Fuel
lamp on if water is detected in the fuel. The water-
in-fuel lamp is located in the instrument panel.
Fig. 7 Water-in-Fuel Sensor
AIR INTAKE HEATER RELAYS-ENGINE
CONTROLLER OUTPUT
The engine controller operates the air intake heat-
ers through the air intake heater relays (Fig. 8). The
relays may be energized before and after cranking,
depending upon intake manifold air temperature.
The engine controller monitors intake manifold air
temperature through the charge temperature sensor.
Refer to Air Intake Heaters in this section.
The relays are not energized during engine crank-
ing. When the solenoids are energized they make a
clicking noise.
CAUTION: Do not energize the air intake heater re-
lays more than once per 15 minutes. If the relays
are cycled, the key turned off, and then turned back
on, the engine could be damaged. Wait 15 minutes
before turning the key back to the ON position.
HEATER
RELAYS
WELL J9114-67
Fig. 8 Air intake Heater Relays
AIR INTAKE HEATER
When energized, the air intake heaters warm in-
coming air as it enters the intake manifold. The air
intake heaters (Fig. 9) are energized by the engine
controller through the air intake heater relays. In-
take manifold air temperature determines when the
heaters are energized. They may be energized before
cranking and after cranking, or both. Refer to Pre-
Heat Cycle and Post Heat Cycle. The heaters are not
energized during cranking.
Fig. 9 Air Intake Heaters
PiEIEAT CYCLE
The engine controller powers up when the ignition
key is turned to the On position. If intake manifold
air temperature is 15°C (59°F) or below, the intake
heaters are energized and the Wait-to-Start light is
illuminated. The heaters are energized for a specific
amount of time, based on the intake manifold air
temperature. Refer to the Air Intake Heater Cycle
Chart.