Oil change DODGE RAM 1500 1998 2.G Manual PDF

EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The evaporator temperature sensor is a two-wire
temperature sensing element located at the coldest
point on the face of the evaporator. The sensor is
attached to the evaporator coil fins. The evaporator
temperature sensor prevents condensation on the
evaporator coil from freezing and obstructing A/C
system air flow. The evaporator temperature sensor
cannot be adjusted or repaired and, if faulty or dam-
aged, it must be replaced.
OPERATION
The evaporator temperature sensor monitors the
temperature of the evaporator. The sensor will
change its internal resistance in response to the tem-
peratures it monitors. The A/C-heater control module
is connected to the sensor through a sensor ground
circuit and a sensor signal circuit. As the evaporator
temperature increases, the resistance of the sensor
decreases and the voltage monitored by the module
decreases. The module uses this monitored voltage
reading to an indication of the evaporator tempera-
ture. The A/C-heater control module is programmed
to respond to this input by cycling the air condition-
ing compressor clutch as necessary to optimize air
conditioning system performance and to protect the
system from evaporator freezing. The external loca-
tion of the sensor allows the sensor to be removed or
installed without disturbing the refrigerant in the
system. The evaporator temperature sensor is diag-
nosed using a DRBIIItscan tool. Refer to Body Diag-
nostic Procedures.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the HVAC housing from the vehicle
(Refer to 24 - HEATING & AIR CONDITIONING/
DISTRIBUTION/HVAC HOUSING - REMOVAL).
(3) Disconnect the HVAC wire harness connector
from the evaporator temperature sensor (Fig. 20).
(4) Disassemble the HVAC housing to gain access
to the evaporator coil (Refer to 24 - HEATING & AIR
CONDITIONING/DISTRIBUTION/HVAC HOUSING
- DISASSEMBLY).
(5) Remove the evaporator temperature sensor
probe from the evaporator coil (Fig. 21).
INSTALLATION
(1) Install the evaporator temperature sensor
probe into the evaporator coil.
Fig. 20 Evaporator Temperature Sensor Wire
Connector
1 - HVAC HOUSING
2 - EVAPORATOR TEMPERATURE SENSOR
3 - HVAC WIRE HARNESS
Fig. 21 Evaporator Temperature Sensor Probe
1 - EVAPORATOR COIL
2 - EVAPORATOR TEMPERATURE SENSOR PROBE
3 - BLEND DOOR
4 - HVAC HOUSING
24 - 22 CONTROLSDR

CCV HOSE
DESCRIPTION - 8.0L V-10
The 8.0L V-10 engine is equipped with a Crankcase
Ventilation (CCV) system. The CCV system performs
the same function as a conventional PCV system, but
does not use a vacuum controlled valve (PCV valve).
A molded vacuum tube connects manifold vacuum
to the top of the right cylinder head (valve) cover.
The vacuum tube connects to a fixed orifice fitting
(Fig. 2) of a calibrated size 2.6 mm (0.10 inches).
OPERATION - 8.0L V-10
A molded vacuum tube connects manifold vacuum
to the top of the right cylinder head (valve) cover.
The vacuum tube connects to a fixed orifice fitting
(Fig. 2) of a calibrated size 2.6 mm (0.10 inches). The
fitting meters the amount of crankcase vapors drawn
out of the engine.The fixed orifice fitting is grey
in color.A similar fitting (but does not contain a
fixed orifice) is used on the left cylinder head (valve)
cover. This fitting is black in color. Do not inter-
change these two fittings.
When the engine is operating, fresh air enters the
engine and mixes with crankcase vapors. Manifold
vacuum draws the vapor/air mixture through the
fixed orifice and into the intake manifold. The vapors
are then consumed during engine combustion.
EVAP/PURGE SOLENOID
DESCRIPTION
The duty cycle EVAP canister purge solenoid is
located in the engine compartment. It is attached to
the side of the Power Distribution Center (PDC).
OPERATION
The Powertrain Control Module (PCM) operates
the solenoid.
During the cold start warm-up period and the hot
start time delay, the PCM does not energize the sole-
noid. When de-energized, no vapors are purged. The
PCM de-energizes the solenoid during open loop oper-
ation.
The engine enters closed loop operation after it
reaches a specified temperature and the time delay
ends. During closed loop operation, the PCM ener-
gizes and de-energizes the solenoid 5 or 10 times per
second, depending upon operating conditions. The
PCM varies the vapor flow rate by changing solenoid
pulse width. Pulse width is the amount of time the
solenoid energizes. The PCM adjusts solenoid pulse
width based on engine operating condition.
REMOVAL
The duty cycle EVAP canister purge solenoid is
located in the engine compartment. It is attached to
the side of the Power Distribution Center (PDC) (Fig.
3).
(1) Disconnect electrical wiring connector at sole-
noid.
(2) Disconnect vacuum harness at solenoid (Fig. 3).
(3) Remove solenoid from mounting bracket.
INSTALLATION
(1) Install solenoid assembly to mounting bracket.
(2) Connect vacuum harness.
(3) Connect electrical connector.
Fig. 2 FIXED ORIFICE FITTING - 8.0L V-10 ENGINE -
TYPICAL
1 - VACUUM TUBE
2 - FIXED ORIFICE FITTING
3 - COIL PACKS
4 - ORIFICE FITTING HOSE CONNECTIONS
25 - 12 EVAPORATIVE EMISSIONSDR