2002 DODGE RAM ECO mode

The primary components within the assembly are:
A three port solenoid that activates both of the func-
tions listed above; a pump which contains a switch,
two check valves and a spring/diaphragm, a canister
vent valve (CVV) seal which contains a spring loaded
vent seal valve.
Immediately after a cold start, between predeter-
mined temperature thresholds limits, the three port
solenoid is briefly energized. This initializes the
pump by drawing air into the pump cavity and also
closes the vent seal. During non test conditions the
vent seal is held open by the pump diaphragm
assembly which pushes it open at the full travel posi-
tion. The vent seal will remain closed while the
pump is cycling due to the reed switch triggering of
the three port solenoid that prevents the diaphragm
assembly from reaching full travel. After the brief
initialization period, the solenoid is de-energized
allowing atmospheric pressure to enter the pump
cavity, thus permitting the spring to drive the dia-
phragm which forces air out of the pump cavity and
into the vent system. When the solenoid is energized
and de energized, the cycle is repeated creating flow
in typical diaphragm pump fashion. The pump is con-
trolled in 2 modes:
Pump Mode: The pump is cycled at a fixed rate to
achieve a rapid pressure build in order to shorten the
overall test length.
Test Mode: The solenoid is energized with a fixed
duration pulse. Subsequent fixed pulses occur when
the diaphragm reaches the Switch closure point.
The spring in the pump is set so that the system
will achieve an equalized pressure of about 7.5º H20.
The cycle rate of pump strokes is quite rapid as the
system begins to pump up to this pressure. As the
pressure increases, the cycle rate starts to drop off. If
there is no leak in the system, the pump would even-
tually stop pumping at the equalized pressure. If
there is a leak, it will continue to pump at a rate rep-
resentative of the flow characteristic of the size of the
leak. From this information we can determine if the
leak is larger than the required detection limit (cur-
rently set at .040º orifice by CARB). If a leak is
revealed during the leak test portion of the test, the
test is terminated at the end of the test mode and no
further system checks will be performed.
After passing the leak detection phase of the test,
system pressure is maintained by turning on the
LDP's solenoid until the purge system is activated.
Purge activation in effect creates a leak. The cycle
rate is again interrogated and when it increases due
to the flow through the purge system, the leak check
portion of the diagnostic is complete.
The canister vent valve will unseal the system
after completion of the test sequence as the pump
diaphragm assembly moves to the full travel position.Evaporative system functionality will be verified by
using the stricter evap purge flow monitor. At an
appropriate warm idle the LDP will be energized to
seal the canister vent. The purge flow will be clocked
up from some small value in an attempt to see a
shift in the 02 control system. If fuel vapor, indicated
by a shift in the 02 control, is present the test is
passed. If not, it is assumed that the purge system is
not functioning in some respect. The LDP is again
turned off and the test is ended.
MISFIRE MONITOR
Excessive engine misfire results in increased cata-
lyst temperature and causes an increase in HC emis-
sions. Severe misfires could cause catalyst damage.
To prevent catalytic convertor damage, the PCM
monitors engine misfire.
The Powertrain Control Module (PCM) monitors
for misfire during most engine operating conditions
(positive torque) by looking at changes in the crank-
shaft speed. If a misfire occurs the speed of the
crankshaft will vary more than normal.
FUEL SYSTEM MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide. The catalyst works best
when the Air Fuel (A/F) ratio is at or near the opti-
mum of 14.7 to 1.
The PCM is programmed to maintain the optimum
air/fuel ratio of 14.7 to 1. This is done by making
short term corrections in the fuel injector pulse width
based on the O2S sensor output. The programmed
memory acts as a self calibration tool that the engine
controller uses to compensate for variations in engine
specifications, sensor tolerances and engine fatigue
over the life span of the engine. By monitoring the
actual fuel-air ratio with the O2S sensor (short term)
and multiplying that with the program long-term
(adaptive) memory and comparing that to the limit,
it can be determined whether it will pass an emis-
sions test. If a malfunction occurs such that the PCM
cannot maintain the optimum A/F ratio, then the
MIL will be illuminated.
CATALYST MONITOR
To comply with clean air regulations, vehicles are
equipped with catalytic converters. These converters
reduce the emission of hydrocarbons, oxides of nitro-
gen and carbon monoxide.
Normal vehicle miles or engine misfire can cause a
catalyst to decay. This can increase vehicle emissions
and deteriorate engine performance, driveability and
fuel economy.
25 - 18 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

INSTALLATION
(1) Install solenoid assembly to support bracket.
(2) Connect vacuum harness.
(3) Connect wiring connector.
FUEL FILLER CAP
DESCRIPTION
The plastic fuel tank filler tube cap is threaded
onto the end of the fuel fill tube. Certain models are
equipped with a 1/4 turn cap.
OPERATION
The loss of any fuel or vapor out of fuel filler tube
is prevented by the use of a pressure-vacuum fuel fill
cap. Relief valves inside the cap will release fuel tank
pressure at predetermined pressures. Fuel tank vac-
uum will also be released at predetermined values.
This cap must be replaced by a similar unit if
replacement is necessary. This is in order for the sys-
tem to remain effective.
CAUTION: Remove fill cap before servicing any fuel
system component to relieve tank pressure. If
equipped with a Leak Detection Pump (LDP), the
cap must be tightened securely. If cap is left loose,
a Diagnostic Trouble Code (DTC) may be set.
REMOVAL/INSTALLATION
If replacement of the 1/4 turn fuel tank filler tube
cap is necessary, it must be replaced with an identi-
cal cap to be sure of correct system operation.
CAUTION: Remove the fuel tank filler tube cap to
relieve fuel tank pressure. The cap must be
removed prior to disconnecting any fuel system
component or before draining the fuel tank.
LEAK DETECTION PUMP
DESCRIPTION
The Leak Detection Pump (LDP) is used only with
certain emission packages.
The LDP is a device used to detect a leak in the
evaporative system.
The pump contains a 3 port solenoid, a pump that
contains a switch, a spring loaded canister vent valve
seal, 2 check valves and a spring/diaphragm.
OPERATION
Immediately after a cold start, engine temperature
between 40ÉF and 86ÉF, the 3 port solenoid is briefly
energized. This initializes the pump by drawing airinto the pump cavity and also closes the vent seal.
During non-test test conditions, the vent seal is held
open by the pump diaphragm assembly which pushes
it open at the full travel position. The vent seal will
remain closed while the pump is cycling. This is due
to the operation of the 3 port solenoid which prevents
the diaphragm assembly from reaching full travel.
After the brief initialization period, the solenoid is
de-energized, allowing atmospheric pressure to enter
the pump cavity. This permits the spring to drive the
diaphragm which forces air out of the pump cavity
and into the vent system. When the solenoid is ener-
gized and de-energized, the cycle is repeated creating
flow in typical diaphragm pump fashion. The pump
is controlled in 2 modes:
PUMP MODE:The pump is cycled at a fixed rate
to achieve a rapid pressure build in order to shorten
the overall test time.
TEST MODE:The solenoid is energized with a
fixed duration pulse. Subsequent fixed pulses occur
when the diaphragm reaches the switch closure
point.
The spring in the pump is set so that the system
will achieve an equalized pressure of about 7.5 inches
of water.
When the pump starts, the cycle rate is quite high.
As the system becomes pressurized pump rate drops.
If there is no leak the pump will quit. If there is a
leak, the test is terminated at the end of the test
mode.
If there is no leak, the purge monitor is run. If the
cycle rate increases due to the flow through the
purge system, the test is passed and the diagnostic is
complete.
The canister vent valve will unseal the system
after completion of the test sequence as the pump
diaphragm assembly moves to the full travel position.
REMOVAL
The LDP and LDP filter are attached to a bracket
mounted to the right-inner fender (Fig. 2). The LDP
and LDP filter are replaced (serviced) as one unit.
(1) Carefully remove hose at LDP filter.
(2) Remove LDP filter mounting bolt and remove
from vehicle.
(3) Carefully remove vapor/vacuum lines at LDP.
(4) Disconnect electrical connector at LDP (Fig. 2).
(5) Remove LDP mounting screws and remove
LDP from vehicle.
INSTALLATION
The LDP and LDP filter are attached to a bracket
mounted to the right-inner fender (Fig. 2) . The LDP
and LDP filter are replaced (serviced) as one unit.
(1) Install LDP to mounting bracket. Tighten
screws to 1 N´m (11 in. lbs.) torque.
25 - 34 EVAPORATIVE EMISSIONSBR/BE
EVAP/PURGE SOLENOID (Continued)

DIESEL - INSTALLATION, WATER PUMP -
5.9L................................7-72
DIESEL - OPERATION.................8E-18
DIESEL - OPERATION.................25-20
DIESEL - OPERATION..........14-106,14-108
DIESEL - OPERATION...................8I-6
DIESEL - OPERATION, BELT
TENSIONERS - 5.9L...................7-23
DIESEL - OPERATION, COOLANT
RECOVERY CONTAINER - 3.9L/5.2L/
5.9L/5.9L............................7-40
DIESEL - OPERATION, ENGINE BLOCK
HEATER - 5.9L........................7-46
DIESEL - OPERATION, ENGINE COOLANT
THERMOSTAT - 5.9L...................7-53
DIESEL - OPERATION, FAN DRIVE
VISCOUS CLUTCH - 5.9L...............7-56
DIESEL - OPERATION, NON-MONITORED
CIRCUITS...........................25-24
DIESEL - OPERATION, RADIATOR - 5.9L . . . 7-62
DIESEL - OPERATION, TRANS COOLER -
5.9L................................7-84
DIESEL - OPERATION, VACUUM PUMP -
5.9L................................7-34
DIESEL - OPERATION, WATER PUMP -
5.9L................................7-72
DIESEL - REMOVAL............14-107,14-108
DIESEL - REMOVAL....................8I-7
DIESEL - REMOVAL, BELT TENSIONERS -
5.9L................................7-23
DIESEL - REMOVAL, COOLANT
RECOVERY CONTAINER - 3.9L/5.2L/
5.9L/5.9L............................7-40
DIESEL - REMOVAL, DRIVE BELTS - 5.9L . . 7-32
DIESEL - REMOVAL, ENGINE BLOCK
HEATER - 5.9L........................7-46
DIESEL - REMOVAL, ENGINE COOLANT
THERMOSTAT - 5.9L...................7-54
DIESEL - REMOVAL, EXHAUST PIPE -
5.9L................................11-9
DIESEL - REMOVAL, MUFFLER - 5.9L.....11-11
DIESEL - REMOVAL, RADIATOR - 5.9L.....7-62
DIESEL - REMOVAL, RADIATOR FAN -
5.9L................................7-43
DIESEL - REMOVAL, TAILPIPE - 5.9L.....11-12
DIESEL - REMOVAL, VACUUM PUMP -
5.9L................................7-34
DIESEL - REMOVAL, WATER PUMP -
5.9L................................7-72
DIESEL ENGINE - DESCRIPTION, FUEL
REQUIREMENTS.......................0-3
DIESEL ENGINE - DIAGNOSIS AND
TESTING............................11-4
DIESEL ENGINE - DIAGNOSIS AND
TESTING, COOLING SYSTEM............7-13
DIESEL ENGINE - INSTALLATION........19-37
DIESEL ENGINE - REMOVAL............19-36
DIESEL ENGINE - STANDARD
PROCEDURE, DRAINING COOLING
SYSTEM 5.9L........................7-15
DIESEL ENGINE - STANDARD
PROCEDURE, REFILLING COOLING
SYSTEM 5.9L........................7-16
DIESEL ENGINE - TORQUE.............14-94
DIESEL ENGINE, SPECIAL TOOLS - 5.9L . . 9-128
DIESEL ENGINES - DESCRIPTION,
COMPONENT MONITORS
..............25-20
DIESEL ENGINES - FUEL SYSTEM
PRESSURES
........................14-62
DIESEL FUEL DELIVERY SYSTEM -
DESCRIPTION
.......................14-55
DIESEL FUEL INJECTION SYSTEM -
DESCRIPTION
.......................14-91
DIESEL FUEL SYSTEM, SPECIAL TOOLS
. . 14-63
DIESEL FUEL TANK - DESCRIPTION
......14-82
DIESEL, SPECIFICATIONS - 5.9L
.........9-127
DIESEL WITH AUTO. TRANS. -
INSTALLATION
..................8P-12,8P-6
DIESEL WITH AUTO. TRANS. -
REMOVAL
.......................8P-5,8P-9
DIFFERENTIAL - ASSEMBLY
....3-126,3-38,3-66,
3-97
DIFFERENTIAL - DISASSEMBLY
. 3-126,3-38,3-65,
3-97
DIFFERENTIAL - INSTALLATION
. 3-126,3-39,3-66,
3-97
DIFFERENTIAL - POWR-LOK - ASSEMBLY
. . 3-99DIFFERENTIAL - POWR-LOK -
DISASSEMBLY........................3-99
DIFFERENTIAL - REMOVAL . 3-125,3-37,3-64,3-96
DIFFERENTIAL - TRAC-LOK - ASSEMBLY . . 3-129,
3-70
DIFFERENTIAL - TRAC-LOK -
DISASSEMBLY...................3-128,3-68
DIFFERENTIAL CASE BEARINGS -
INSTALLATION.........3-102,3-129,3-41,3-72
DIFFERENTIAL CASE BEARINGS -
REMOVAL.............3-102,3-129,3-40,3-72
DIMENSION, SPECIFICATIONS - FRAME....13-8
DIMENSIONS, SPECIFICATIONS - BODY
OPENING...........................23-60
DIODE - INSTALLATION............8W-01-13
DIODE - REMOVAL................8W-01-13
DIODE REPLACEMENT - STANDARD
PROCEDURE.........................24-7
DISASSEMBLY - OVERHEAD CONSOLE
DISASSEMBLY.......................8M-7
DISASSEMBLY, AXLE VACUUM MOTOR....3-34
DISASSEMBLY, DIAGNOSIS AND
TESTING....................21-115,21-287
DISASSEMBLY, DIFFERENTIAL . . 3-126,3-38,3-65,
3-97
DISASSEMBLY, DIFFERENTIAL -
POWR-LOK..........................3-99
DISASSEMBLY, DIFFERENTIAL -
TRAC-LOK......................3-128,3-68
DISASSEMBLY, DISASSEMBLY -
OVERHEAD CONSOLE.................8M-7
DISASSEMBLY, DOUBLE CARDAN
UNIVERSAL JOINTS...................3-10
DISASSEMBLY, DRIVER AIRBAG.........8O-15
DISASSEMBLY, FLYWHEEL..............6-13
DISASSEMBLY, FRONT CLUTCH . . 21-161,21-331
DISASSEMBLY, FRONT SERVO . . . 21-164,21-334
DISASSEMBLY, GLOVE BOX...........23-110
DISASSEMBLY, HVAC HOUSING.........24-35
DISASSEMBLY, INSTRUMENT CLUSTER . . . 8J-10
DISASSEMBLY, MANUAL - NV4500........21-5
DISASSEMBLY, MANUAL - NV5600.......21-49
DISASSEMBLY, OIL PUMP...............9-47
DISASSEMBLY, OIL PUMP.......21-167,21-337
DISASSEMBLY, OVERDRIVE UNIT . 21-173,21-346
DISASSEMBLY, OVERRUNNING CLUTCH
CAM/OVERDRIVE PISTON RETAINER....21-192,
21-364
DISASSEMBLY, PLANETARY GEARTRAIN/
OUTPUT SHAFT...............21-198,21-369
DISASSEMBLY, REAR CLUTCH . . . 21-204,21-376
DISASSEMBLY, REAR SERVO....21-207,21-378
DISASSEMBLY, REMOVAL...............5-11
DISASSEMBLY, SINGLE CARDAN
UNIVERSAL JOINTS....................3-8
DISASSEMBLY, STANDARD PROCEDURE . . . 7-80
DISASSEMBLY, TRANSFER CASE -
NV241HD..........................21-469
DISASSEMBLY, TRANSFER CASE -
NV241LD..........................21-432
DISASSEMBLY, VALVE BODY.....21-237,21-409
DISC - INSTALLATION, CLUTCH...........6-8
DISC - REMOVAL, CLUTCH...............6-7
DISC BRAKE CALIPERS - DESCRIPTION....5-10
DISC BRAKE CALIPERS - OPERATION.....5-10
DISC BRAKE ROTOR, DIAGNOSIS AND
TESTING............................5-20
DISCHARGE (ESD) SENSITIVE DEVICES -
STANDARD PROCEDURE,
ELECTROSTATIC...................8W-01-8
DISCHARGE LINE - INSTALLATION,
SUCTION...........................24-52
DISCHARGE LINE - REMOVAL, SUCTION . . 24-51
DISPLAY TEST MODE - DESCRIPTION,
STATE ..............................25-1
DISTRIBUTION - DESCRIPTION, POWER . 8W-97-1
DISTRIBUTION - OPERATION, POWER . . 8W-97-1
DISTRIBUTION CENTER - DESCRIPTION,
POWER..........................8W-97-8
DISTRIBUTION CENTER - INSTALLATION,
POWER
.........................8W-97-10
DISTRIBUTION CENTER - OPERATION,
POWER
..........................8W-97-8
DISTRIBUTION CENTER - REMOVAL,
POWER
..........................8W-97-8
DISTRIBUTION SYSTEMS, SPECIAL
TOOLS - POWER
...................8W-97-2
DISTRIBUTOR - DESCRIPTION
..........8I-11DISTRIBUTOR - INSTALLATION..........8I-13
DISTRIBUTOR - OPERATION............8I-12
DISTRIBUTOR - REMOVAL..............8I-12
DISTRIBUTOR BUSHING - INSTALLATION . . 9-35
DISTRIBUTOR BUSHING - REMOVAL......9-35
DISTRIBUTOR CAP - DIAGNOSIS AND
TESTING............................8I-14
DISTRIBUTOR ROTOR - DIAGNOSIS AND
TESTING............................8I-14
DOME LAMP - INSTALLATION..........8L-34
DOME LAMP - REMOVAL..............8L-34
DOOR - ADJUSTMENT, CARGO..........23-78
DOOR - INSTALLATION...........23-69,23-78
DOOR - INSTALLATION, BLEND.........24-37
DOOR - INSTALLATION, FUEL FILL.......23-95
DOOR - INSTALLATION, HEAT/DEFROST . . . 24-38
DOOR - INSTALLATION, PANEL/DEFROST . . 24-38
DOOR - INSTALLATION, RECIRCULATION . . 24-39
DOOR - REMOVAL...............23-69,23-78
DOOR - REMOVAL, BLEND.............24-37
DOOR - REMOVAL, FUEL FILL..........23-95
DOOR - REMOVAL, HEAT/DEFROST......24-37
DOOR - REMOVAL, PANEL/DEFROST.....24-38
DOOR - REMOVAL, RECIRCULATION.....24-38
DOOR ACTUATOR - INSTALLATION,
BLEND.............................24-25
DOOR ACTUATOR - INSTALLATION,
HEAT/DEFROST......................24-27
DOOR ACTUATOR - INSTALLATION,
PANEL/DEFROST.....................24-27
DOOR ACTUATOR - INSTALLATION,
RECIRCULATION.....................24-28
DOOR ACTUATOR - REMOVAL, BLEND....24-25
DOOR ACTUATOR - REMOVAL,
HEAT/DEFROST......................24-26
DOOR ACTUATOR - REMOVAL,
PANEL/DEFROST.....................24-26
DOOR ACTUATOR - REMOVAL,
RECIRCULATION.....................24-27
DOOR AJAR SWITCH - DESCRIPTION....8L-34
DOOR AJAR SWITCH - DIAGNOSIS AND
TESTING...........................8L-34
DOOR AJAR SWITCH - INSTALLATION....8L-35
DOOR AJAR SWITCH - REMOVAL........8L-35
DOOR CYLINDER LOCK SWITCH -
DESCRIPTION........................8N-5
DOOR CYLINDER LOCK SWITCH -
DIAGNOSIS AND TESTING..............8N-6
DOOR CYLINDER LOCK SWITCH -
INSTALLATION.......................8N-6
DOOR CYLINDER LOCK SWITCH -
OPERATION..........................8N-5
DOOR CYLINDER LOCK SWITCH -
REMOVAL...........................8N-6
DOOR FORE/AFT - ADJUSTMENT, FRONT . . 23-69
DOOR GLASS - INSTALLATION..........23-70
DOOR GLASS - REMOVAL.............23-70
DOOR GLASS RUN WEATHERSTRIP -
INSTALLATION, FRONT...............23-153
DOOR GLASS RUN WEATHERSTRIP -
REMOVAL, FRONT...................23-152
DOOR INNER BELT WEATHERSTRIP -
INSTALLATION, FRONT...............23-153
DOOR INNER BELT WEATHERSTRIP -
REMOVAL, FRONT...................23-153
DOOR IN/OUT - ADJUSTMENT, FRONT....23-70
DOOR LATCH - ADJUSTMENT, FRONT....23-73
DOOR OPENING SEAL - INSTALLATION . . 23-152
DOOR OPENING SEAL - REMOVAL......23-152
DOOR OUTER BELT WEATHERSTRIP -
INSTALLATION, FRONT...............23-153
DOOR OUTER BELT WEATHERSTRIP -
REMOVAL, FRONT...................23-153
DOOR SEAL - INSTALLATION, B-PILLAR . 23-151
DOOR SEAL - REMOVAL, B-PILLAR.....23-151
DOOR SECOND WEATHERSTRIP -
INSTALLATION, FRONT...............23-154
DOOR SECOND WEATHERSTRIP -
REMOVAL, FRONT...................23-154
DOOR SILL TRIM - INSTALLATION......23-121
DOOR SILL TRIM - REMOVAL.........23-121
DOOR SPEAKER - INSTALLATION, FRONT . 8A-19
DOOR SPEAKER - INSTALLATION, REAR
. . 8A-21
DOOR SPEAKER - REMOVAL, FRONT
.....8A-19
DOOR SPEAKER - REMOVAL, REAR
......8A-20
DOOR UP/DOWN - ADJUSTMENT, FRONT
. 23-70
DOOR UPPER CORNER SEAL -
INSTALLATION, FRONT
...............23-154
10 INDEXBR/BE
Description Group-Page Description Group-Page Description Group-Page