Chrysler 300M Service Manual page 209

7 - 22 ENGINE
ENGINE COOLANT TEMPERATURE SENSOR (Continued)
Fig. 6 ENGINE COOLANT TEMPERATURE SENSOR -
1 - CAMSHAFT POSITION SENSOR
2 - ENGINE COOLANT TEMPERATURE SENSOR
OPERATION
The sensor provides an input to the Powertrain
Control Module (PCM). As coolant temperature var-
ies, the sensor resistance changes, resulting in a dif-
ferent input voltage to the PCM.
When the engine is cold, the PCM will demand
slightly richer air-fuel mixtures and higher idle
speeds until normal operating temperatures are
reached.
The engine coolant sensor input also determines
operation of the low and high speed cooling fans.
REMOVAL
(1) Disconnect negative cable from remote jumper
terminal.
(2) With the engine cold, disconnect coolant sensor
electrical connector (Fig. 5) or (Fig. 6).
(3) Remove sensor.
INSTALLATION
(1) Install engine coolant temperature sensor (Fig.
5) or (Fig. 6). Tighten sensor to 28 N·m (20 ft. lbs.)
torque.
(2) Attach electrical connector to sensor.
(3) Connect negative cable to remote jumper termi-
nal.
3.5L
ENGINE COOLANT
THERMOSTAT
DESCRIPTION
The thermostat on the 2.7L and 3.5L engines are
located on the lower left side of engine, near the
front (Fig. 7) and (Fig. 8). The thermostat on both
engines are on the inlet side of the water pump. The
thermostats have an air bleed located in the thermo-
stat flange. The air bleed allows internal trapped air
during cooling system filling to be released.
Fig. 7 THERMOSTAT AND HOUSING - 2.7L
1 - THERMOSTAT AND GASKET
2 - THERMOSTAT HOUSING/COOLANT INLET
OPERATION
The engine cooling thermostat is a wax pellet
driven, reverse poppet type. The thermostat is
located in the inlet side of the engine to provide fast
warm up and to optimize a consistent temperature in
the engine. The thermostat is designed to prevent
leakage through it and to guarantee a minimum
engine operating temperature of 82°C (180°F). They
also automatically reach wide open at a temperature
of approximately 95°C (203°F) so they do not restrict
flow to the radiator as temperature of the coolant
rises in hot weather to around 104°C (220°F). Above
102°C (215°F) the coolant temperature is controlled
by the radiator, fan, and ambient temperature, not
the thermostat.
LH