charging DODGE RAM 2002 Service Workshop Manual

(3) Tighten the cylinder head bolts in two steps
(Fig. 10):
²Step 1ÐTighten all cylinder head bolts, in
sequence, to 58 N´m (43 ft. lbs.) torque.
²Step 2ÐTighten all cylinder head bolts, in
sequence, to 143 N´m (105 ft. lbs.) torque.
²
CAUTION: When tightening the rocker arm bolts,
make sure the piston in that cylinder is NOT at
TDC. Contact between the valves and piston could
occur.
(4) Install push rods and rocker arm assemblies in
their original position (Refer to 9 - ENGINE/CYLIN-
DER HEAD/ROCKER ARM / ADJUSTER ASSY -
INSTALLATION).
(5) Install lower intake manifold (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
INSTALLATION).
(6) Install the upper intake manifold onto the
lower intake manifold (Refer to 9 - ENGINE/MANI-
FOLDS/INTAKE MANIFOLD - INSTALLATION).
(7) Install the exhaust manifolds and new gaskets
(Refer to 9 - ENGINE/MANIFOLDS/EXHAUST
MANIFOLD - INSTALLATION).
(8) Install exhaust pipe to the exhaust manifold.
Tighten the bolts to 34 n´m (25 ft. lbs.) torque.
(9) Using a new gasket, position the EGR tube to
the intake manifold and the exhaust manifold.
Tighten the EGR tube nut to 34 N´m (25 ft. lbs.)
torque. Tighten the bolts to 20 N´m (174 in. lbs.)
torque.
(10) Install the heat shields and the washers.
Make sure that heat shields tabs hook over the
exhaust gasket.Tighten the nuts to 15 N´m (132 in.
lbs.) torque.
(11) Adjust and Install the spark plugs (Refer to 8
- ELECTRICAL/IGNITION CONTROL/SPARK
PLUG - INSTALLATION).
(12) Install coil packs and bracket. Tighten the
bracket bolts to 21 N´m (190 in. lbs.) torque. Connect
the coil wires.
(13) Connect heat indicator sending unit wire.
(14) Connect the heater hoses and bypass hose.(15) Connect the accelerator linkage and if so
equipped, the speed control and transmission kick-
down cables.
(16) Install the fuel line (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE).
(17) Install the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - INSTALLATION)
and drive belt (Refer to 7 - COOLING/ACCESSORY
DRIVE/DRIVE BELTS - INSTALLATION).
(18) Install the intake manifold-to-generator
bracket support rod. Tighten the bolts to 41 N´m (30
ft. lbs.) torque.
(19) The cylinder head cover gasket can be used
again. Install the gasket onto the head rail.For the
left side the number tab is at the front of
engine with the number up. For the right side
the number tab is at the rear of engine with the
number up.
CAUTION: The cylinder head cover fasteners have a
special plating. DO NOT use alternative fasteners.
(20) Install cylinder head cover (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(21) Install closed crankcase ventilation system.
(22) Connect the evaporation control system.
(23) Install the air cleaner.
(24) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(25) Connect the negative cable to the battery.
(26) Check for leaks (fuel, oil, antifreeze, etc.).
CYLINDER HEAD COVER(S)
DESCRIPTION
Die-cast magnesium cylinder head covers (Fig. 11)
reduce noise and provide a good sealing surface. A
steel backed silicon gasket is used with the cylinder
head cover. This gasket can be used again.
REMOVAL
Die-cast magnesium cylinder head covers (Fig. 13)
reduce noise and provide a good sealing surface. A
steel backed silicon gasket is used with the cylinder
head cover (Fig. 12).
(1) Disconnect the negative cable from the battery.
(2) Disconnect closed ventilation system and evap-
oration control system from cylinder head cover.
Identify each system for installation.
(3) Remove the upper intake manifold to remove
the right side head cover (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - REMOVAL).
Fig. 10 Cylinder Head Bolt Tightening Sequence
9 - 78 ENGINE 8.0LBR/BE
CYLINDER HEAD (Continued)

(15) Install the fuel lines (Refer to 14 - FUEL SYS-
TEM/FUEL DELIVERY/QUICK CONNECT FIT-
TING - STANDARD PROCEDURE).
(16) Using a new gasket, install the air cleaner
housing. Tighten the nuts to 11 N´m (96 in. lbs.)
torque. Install the air cleaner filter and cover.
(17) Install the A/C compressor (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION). Position the com-
pressor brace and install the bolts. Tighten the brace
bolts to 41 N´m (30 ft. lbs.) torque.
(18) Install the generator (Refer to 8 - ELECTRI-
CAL/CHARGING/GENERATOR - INSTALLATION).
Position the generator brace and install the bolts.
Tighten the brace bolts to 41 N´m (30 ft. lbs.) torque.
(19) Install the accessory drive belt (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
INSTALLATION).
(20) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(21) Connect the negative cable to the battery.
(22) Start engine check for leaks.
EXHAUST MANIFOLD
DESCRIPTION
Engine exhaust manifolds (Fig. 75) are made of
high molybdenum ductile cast iron. A special ribbed
design helps control permanent dimensional changes
during heat cycles.
OPERATION
The exhaust manifolds collect the engine exhaust
exiting the combustion chambers, then channels the
exhaust gases to the exhaust pipes attached to the
manifolds.
REMOVAL
(1) Disconnect the negative cable from the battery.
(2) Raise and support the vehicle.
(3) Remove the bolts and nuts attaching the
exhaust pipe to the engine exhaust manifold..
(4) Lower the vehicle.
(5) Remove the exhaust heat shields (Fig. 76).
(6) Remove the dipstick bracket from the exhaust
manifold (right side only).
(7) Remove bolts attaching manifold to cylinder
head.
(8) Remove manifold from the cylinder head. Dis-
card the gasket.
CLEANING
Clean mating surfaces on cylinder head and mani-
fold. Wash with solvent and blow dry with com-
pressed air.
INSPECTION
Inspect manifold for cracks.
Inspect mating surfaces of manifold for flatness
with a straight edge. Gasket surfaces must be flat
within 0.2 mm per 300 mm (0.008 inch per foot).
INSTALLATION
(1) Using a new gasket position the engine
exhaust manifold onto the cylinder head. Install bolts
and stud bolts in the proper position (Fig. 76).
Tighten the bolts to 22 N´m (16 ft. lbs.) torque.
Fig. 75 Exhaust ManifoldÐ8.0L Engine
1 - EXHAUST MANIFOLD
Fig. 76 8.0L Engine Exhaust ManifoldÐTypical
1 - EXHAUST MANIFOLD
2 - HEAT SHIELD
BR/BEENGINE 8.0L 9 - 109
INTAKE MANIFOLD (Continued)

FUEL INJECTION - DIESEL
TABLE OF CONTENTS
page page
FUEL INJECTION - DIESEL
DESCRIPTION - DIESEL FUEL INJECTION
SYSTEM............................91
DIAGNOSIS AND TESTING - BOOST
PRESSURE..........................93
SPECIFICATIONS
TORQUE - DIESEL ENGINE.............94
ACCELERATOR PEDAL POSITION SENSOR
DESCRIPTION.........................95
OPERATION...........................95
REMOVAL.............................95
INSTALLATION.........................97
FUEL INJECTOR
DESCRIPTION.........................97
OPERATION...........................98
DIAGNOSIS AND TESTINGÐFUEL INJECTOR
TEST...............................99
REMOVAL............................101
INSTALLATION........................102
FUEL INJECTION PUMP RELAY
DESCRIPTION........................103
OPERATION..........................103
FUEL TEMPERATURE SENSOR
DESCRIPTION........................104
OPERATION..........................104
INTAKE AIR HEATER
DESCRIPTION........................104OPERATION..........................104
REMOVAL............................104
INSTALLATION........................105
INTAKE AIR HEATER RELAY
DESCRIPTION........................105
OPERATION..........................105
REMOVAL............................106
INSTALLATION........................106
INTAKE AIR TEMPERATURE SENSOR
DESCRIPTION - DIESEL.................106
OPERATION - DIESEL..................106
REMOVAL - DIESEL....................107
INSTALLATION - DIESEL................107
MAP SENSOR
DESCRIPTION - DIESEL.................108
OPERATION - DIESEL..................108
REMOVAL - DIESEL....................108
INSTALLATION........................108
PTO SWITCH
DESCRIPTION
OPERATION........................108
THROTTLE CONTROL CABLE
REMOVAL............................109
INSTALLATION........................110
FUEL INJECTION - DIESEL
DESCRIPTION - DIESEL FUEL INJECTION
SYSTEM
The Engine Control Module (ECM) and Fuel Injec-
tion Pump Control Module (FPCM) are used prima-
rily for fuel system control. The ECM is a separate
replaceable component, while the FPCM is internal
to the fuel injection pump and is a non-serviceable
part. The ECM and FPCM are interconnected (wired
together) for fuel injection control.The Powertrain Control Module (PCM) is used to
regulate or control the A/C, charging and speed con-
trol systems. It is also used to partially control cer-
tain electronic automatic transmission components.
The PCM also has control over certain instrument
panel components.
Refer to either Powertrain Control Module (PCM)
or Engine Control Module (ECM) for additional infor-
mation. Refer to (Fig. 1) for a partial list of fuel sys-
tem components.
BR/BEFUEL INJECTION - DIESEL 14 - 91

(4) Reinstall the cluster bezel to the instrument
panel(Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).
(5) Reach under the instrument panel to reinstall
the a/c heater control vacuum harness retainer to the
side of the center distribution duct.
(6) Plug in the two halves of the a/c heater control
to HVAC housing vacuum harness connector.
(7) Connect the battery negative cable.
A/C HIGH PRESSURE SWITCH
DESCRIPTION
The a/c high pressure switch is located on the dis-
charge line near the compressor. The switch is
screwed onto a fitting that contains a Schrader-type
valve, which allows the switch to be serviced without
discharging the refrigerant system. The discharge
line fitting is equipped with an O-ring to seal the
switch connection.
OPERATION
The a/c high pressure switch is connected in series
electrically with the a/c low pressure switch between
ground and the Powertrain Control Module (PCM).
The switch contacts open and close causing the PCM
to turn the compressor clutch on and off. This pre-
vents compressor operation when the discharge line
pressure approaches high levels.
The a/c high pressure switch contacts are open
when the discharge line pressure rises above about3100 to 3375 kPa (450 to 490 psi). The switch con-
tacts will close when the discharge line pressure
drops to about 1860 to 2275 kPa (270 to 330 psi).
When checking refrigerant system pressures with a
manifold gauge set, keep in mind that the indicated
pressures will be about 172 kpa (25 psi) below the
actual switch pressure values due to the pressure
drop that occurs in the refrigerant system between
the switch and the high pressure service port.
The a/c high pressure switch is a factory-calibrated
unit. The switch cannot be adjusted or repaired and,
if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - A/C HIGH
PRESSURE SWITCH
Before performing diagnosis of the a/c high pres-
sure switch, verify that the refrigerant system has
the correct refrigerant charge. (Refer to 24 - HEAT-
ING & AIR CONDITIONING - DIAGNOSIS AND
TESTING)
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the a/c high pressure switch wire har-
ness connector from the switch on the refrigerant
system fitting.
(3) On the four terminal high pressure switch,
check for continuity between terminals C and D. On
the two terminal switch, check for continuity
between both terminals of the a/c high pressure
switch. There should be continuity. If OK, test and
repair the A/C switch sense circuit as required. If not
OK, replace the faulty switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the a/c
high pressure switch, which is mounted to a fitting
on the discharge line between the compressor and
the condenser inlet.
(3) Unscrew the a/c high pressure switch from the
discharge line fitting.
(4) Remove the a/c high pressure switch from the
vehicle.
(5) Remove the O-ring seal from the discharge line
fitting and discard.
INSTALLATION
(1) Lubricate a new O-ring seal with clean refrig-
erant oil and install it on the discharge line fitting.
Use only the specified O-rings as they are made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the com-
pressor in the vehicle. (Refer to 24 - HEATING &
Fig. 19 A/C HEATER CONTROL REMOVE/INSTALL
1 - HEATED MIRROR WIRE HARNESS CONNECTOR
2 - WIRE HARNESS CONNECTOR
3 - SCREW
4 - HEATER-A/C CONTROL
24 - 20 CONTROLSBR/BE
A/C-HEATER CONTROL (Continued)

AIR CONDITIONING/PLUMBING/REFRIGERANT
OIL - DESCRIPTION)
(2) Install and tighten the high pressure cut-off
switch on the discharge line fitting. The switch
should be hand-tightened onto the discharge line fit-
ting.
(3) Plug the wire harness connector into the high
pressure cut-off switch.
(4) Connect the battery negative cable.
A/C LOW PRESSURE SWITCH
DESCRIPTION
The a/c low pressure switch is located on the top of
the accumulator. The switch is screwed onto an accu-
mulator fitting that contains a Schrader-type valve,
which allows the switch to be serviced without dis-
charging the refrigerant system. The accumulator fit-
ting is equipped with an O-ring to seal the switch
connection.
OPERATION
The a/c low pressure switch is connected in series
electrically with the a/c high pressure switch and the
a/c heater control, between ground and the Power-
train Control Module (PCM). The switch contacts
open and close causing the PCM to turn the compres-
sor clutch on and off. This regulates the refrigerant
system pressure and controls evaporator tempera-
ture. Controlling evaporator temperature prevents
condensate water on the evaporator fins from freez-
ing and obstructing air conditioning system air flow.
The a/c low pressure switch contacts are open
when the suction pressure is about 152-165 kPa
(22-24 psi) or lower. The switch contacts will close
when the suction pressure rises to about 255-296 kPa
(37-43 psi) or above. Lower ambient temperatures,
below about -1É C (30É F), will also cause the switch
contacts to open. This is due to the pressure/temper-
ature relationship of the refrigerant in the system.
The a/c low pressure switch is a factory-calibrated
unit. It cannot be adjusted or repaired and, if faulty
or damaged, it must be replaced.
DIAGNOSIS AND TESTING - A/C LOW
PRESSURE SWITCH
Before performing diagnosis of the a/c low pressure
switch, be certain that the switch is properly
installed on the accumulator fitting. If the switch is
too loose it may not open the Schrader-type valve in
the accumulator fitting, which will prevent the
switch from correctly monitoring the refrigerant sys-
tem pressure. Also verify that the refrigerant system
has the correct refrigerant charge. (Refer to 24 -HEATING & AIR CONDITIONING - DIAGNOSIS
AND TESTING - A/C PERFORMANCE)
Remember that lower ambient temperatures, below
about -1É C (30É F), during cold weather will open the
switch contacts and prevent compressor operation
due to the pressure/temperature relationship of the
refrigerant. For circuit descriptions and diagrams,
(Refer to Appropriate Wiring Information).
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the a/c low pressure switch wire har-
ness connector from the switch on the accumulator
fitting.
(3) Install a jumper wire between the two cavities
of the a/c low pressure switch wire harness connector.
(4) Connect a manifold gauge set to the refrigerant
system service ports. (Refer to 24 - HEATING & AIR
CONDITIONING/PLUMBING - STANDARD PRO-
CEDURE - REFRIGERANT SYSTEM SERVICE
EQUIPMENT)
(5) Connect the battery negative cable.
(6) Place the a/c heater mode control switch knob
in any A/C position and start the engine.
(7) Check for continuity between the two terminals
of the low pressure cycling clutch switch. There
should be continuity with a suction pressure reading
of 296 kPa (43 psi) or above, and no continuity with a
suction pressure reading of 172 kPa (25 psi) or below.
If OK, test and repair the A/C switch sense circuit as
required. If not OK, replace the faulty switch.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the wire harness connector from the a/c
low pressure switch on the top of the accumulator
(Fig. 20).
(3) Unscrew the a/c low pressure switch from the
fitting on the top of the accumulator.
(4) Remove the O-ring seal from the accumulator
fitting and discard.
INSTALLATION
(1) Lubricate a new O-ring seal with clean refrig-
erant oil and install it on the accumulator fitting.
Use only the specified O-rings as they are made of a
special material for the R-134a system. Use only
refrigerant oil of the type recommended for the com-
pressor in the vehicle. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING/REFRIGERANT
OIL - DESCRIPTION)
(2) Install and tighten the a/c low pressure switch
on the accumulator fitting. The switch should be
hand-tightened onto the accumulator fitting.
(3) Plug the wire harness connector into the a/c
low pressure switch.
BR/BECONTROLS 24 - 21
A/C HIGH PRESSURE SWITCH (Continued)

SERVICE WARNINGS
WARNING:
THE AIR CONDITIONING SYSTEM CONTAINS
REFRIGERANT UNDER HIGH PRESSURE. SEVERE
PERSONAL INJURY MAY RESULT FROM IMPROPER
SERVICE PROCEDURES. REPAIRS SHOULD ONLY
BE PERFORMED BY QUALIFIED SERVICE PERSON-
NEL.
AVOID BREATHING THE REFRIGERANT AND
REFRIGERANT OIL VAPOR OR MIST. EXPOSURE
MAY IRRITATE THE EYES, NOSE, AND/OR THROAT.
WEAR EYE PROTECTION WHEN SERVICING THE
AIR CONDITIONING REFRIGERANT SYSTEM. SERI-
OUS EYE INJURY CAN RESULT FROM DIRECT
CONTACT WITH THE REFRIGERANT. IF EYE CON-
TACT OCCURS, SEEK MEDICAL ATTENTION IMME-
DIATELY.
DO NOT EXPOSE THE REFRIGERANT TO OPEN
FLAME. POISONOUS GAS IS CREATED WHEN
REFRIGERANT IS BURNED. AN ELECTRONIC LEAK
DETECTOR IS RECOMMENDED.
IF ACCIDENTAL SYSTEM DISCHARGE OCCURS,
VENTILATE THE WORK AREA BEFORE RESUMING
SERVICE. LARGE AMOUNTS OF REFRIGERANT
RELEASED IN A CLOSED WORK AREA WILL DIS-
PLACE THE OXYGEN AND CAUSE SUFFOCATION.
THE EVAPORATION RATE OF R-134a REFRIGER-
ANT AT AVERAGE TEMPERATURE AND ALTITUDE
IS EXTREMELY HIGH. AS A RESULT, ANYTHING
THAT COMES IN CONTACT WITH THE REFRIGER-
ANT WILL FREEZE. ALWAYS PROTECT THE SKIN
OR DELICATE OBJECTS FROM DIRECT CONTACT
WITH THE REFRIGERANT.
THE R-134a SERVICE EQUIPMENT OR THE VEHI-
CLE REFRIGERANT SYSTEM SHOULD NOT BE
PRESSURE TESTED OR LEAK TESTED WITH COM-
PRESSED AIR. SOME MIXTURES OF AIR AND
R-134a HAVE BEEN SHOWN TO BE COMBUSTIBLE
AT ELEVATED PRESSURES. THESE MIXTURES ARE
POTENTIALLY DANGEROUS, AND MAY RESULT IN
FIRE OR EXPLOSION CAUSING INJURY OR PROP-
ERTY DAMAGE.
SERVICE CAUTIONS
CAUTION: Liquid refrigerant is corrosive to metal
surfaces. Follow the operating instructions supplied
with the service equipment being used.
Never add R-12 to a refrigerant system designed to
use R-134a. Damage to the system will result.
R-12 refrigerant oil must not be mixed with R-134a
refrigerant oil. They are not compatible.
Do not use R-12 equipment or parts on the R-134a
system. Damage to the system will result.Do not overcharge the refrigerant system. This will
cause excessive compressor head pressure and
can cause noise and system failure.
Recover the refrigerant before opening any fitting
or connection. Open the fittings with caution, even
after the system has been discharged. Never open
or loosen a connection before recovering the refrig-
erant.
Do not remove the secondary retention clip from
any spring-lock coupler connection while the refrig-
erant system is under pressure. Recover the refrig-
erant before removing the secondary retention clip.
Open the fittings with caution, even after the sys-
tem has been discharged. Never open or loosen a
connection before recovering the refrigerant.
The refrigerant system must always be evacuated
before charging.
Do not open the refrigerant system or uncap a
replacement component until you are ready to ser-
vice the system. This will prevent contamination in
the system.
Before disconnecting a component, clean the out-
side of the fittings thoroughly to prevent contami-
nation from entering the refrigerant system.
Immediately after disconnecting a component from
the refrigerant system, seal the open fittings with a
cap or plug.
Before connecting an open refrigerant fitting,
always install a new seal or gasket. Coat the fitting
and seal with clean refrigerant oil before connect-
ing.
Do not remove the sealing caps from a replacement
component until it is to be installed.
When installing a refrigerant line, avoid sharp
bends that may restrict refrigerant flow. Position the
refrigerant lines away from exhaust system compo-
nents or any sharp edges, which may damage the
line.
Tighten refrigerant fittings only to the specified
torque. The aluminum fittings used in the refriger-
ant system will not tolerate overtightening.
When disconnecting a refrigerant fitting, use a
wrench on both halves of the fitting. This will pre-
vent twisting of the refrigerant lines or tubes.
Refrigerant oil will absorb moisture from the atmo-
sphere if left uncapped. Do not open a container of
refrigerant oil until you are ready to use it. Replace
the cap on the oil container immediately after using.
Store refrigerant oil only in a clean, airtight, and
moisture-free container.
Keep service tools and the work area clean. Con-
tamination of the refrigerant system through care-
less work habits must be avoided.
24 - 42 PLUMBINGBR/BE
PLUMBING (Continued)

(6) Push together firmly on the two halves of the
coupler fitting until the garter spring in the cage on
the male half of the fitting snaps over the flanged
end on the female half of the fitting.
(7) Ensure that the spring-lock coupler is fully
engaged by trying to separate the two coupler halves.
This is done by pulling the refrigerant lines on either
side of the coupler away from each other.
(8) Reinstall the secondary clip over the spring-
lock coupler cage.
STANDARD PROCEDURE - REFRIGERANT
SYSTEM SERVICE EQUIPMENT
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
When servicing the air conditioning system, a
R-134a refrigerant recovery/recycling/charging sta-
tion that meets SAE Standard J2210 must be used.
Contact an automotive service equipment supplier for
refrigerant recovery/recycling/charging equipment.
Refer to the operating instructions supplied by the
equipment manufacturer for proper care and use of
this equipment.
A manifold gauge set may be needed with some
recovery/recycling/charging equipment (Fig. 3). The
service hoses on the gauge set being used should
have manual (turn wheel), or automatic back-flow
valves at the service port connector ends. This will
prevent refrigerant from being released into the
atmosphere.
MANIFOLD GAUGE SET CONNECTIONS
CAUTION: Do not use an R-12 manifold gauge set
on an R-134a system. The refrigerants are not com-
patible and system damage will result.
LOW PRESSURE GAUGE HOSE The low pressure
hose (Blue with Black stripe) attaches to the suction
service port. This port is located on the suction line
between the accumulator outlet and the compressor.
HIGH PRESSURE GAUGE HOSE The high pres-
sure hose (Red with Black stripe) attaches to the dis-
charge service port. This port is located on the
discharge line between the compressor and the con-
denser inlet.
RECOVERY/RECYCLING/EVACUATION/CHARG-
ING HOSE The center manifold hose (Yellow, or
White, with Black stripe) is used to recover, evacu-
ate, and charge the refrigerant system. When the low
or high pressure valves on the manifold gauge setare opened, the refrigerant in the system will escape
through this hose.
STANDARD PROCEDURE - REFRIGERANT
RECOVERY
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to recover the refrigerant from an R-134a refrig-
erant system. Refer to the operating instructions sup-
plied by the equipment manufacturer for the proper
care and use of this equipment.
Fig. 3 MANIFOLD GAUGE SET - TYPICAL
1 - HIGH PRESSURE GAUGE
2 - VALVE
3 - VACUUM/REFRIGERANT HOSE (YELLOW W/ BLACK
STRIPE)
4 - HIGH PRESSURE HOSE (RED W/ BLACK STRIPE)
5 - LOW PRESSURE HOSE (BLUE W/ BLACK STRIPE)
6 - VALVE
7 - LOW PRESSURE GAUGE
BR/BEPLUMBING 24 - 45
PLUMBING (Continued)

STANDARD PROCEDURE - REFRIGERANT
SYSTEM EVACUATE
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
If the refrigerant system has been open to the
atmosphere, it must be evacuated before the system
can be charged. If moisture and air enters the system
and becomes mixed with the refrigerant, the com-
pressor head pressure will rise above acceptable
operating levels. This will reduce the performance of
the air conditioner and damage the compressor.
Evacuating the refrigerant system will remove the
air and boil the moisture out of the system at near
room temperature. To evacuate the refrigerant sys-
tem, use the following procedure:
(1) Connect a R-134a refrigerant recovery/recy-
cling/charging station that meets SAE Standard
J2210 and a manifold gauge set to the refrigerant
system of the vehicle.
(2) Open the low and high side valves and start
the charging station vacuum pump. When the suc-
tion gauge reads 88 kPa (26 in. Hg.) vacuum or
greater, close all of the valves and turn off the vac-
uum pump.
(a) If the refrigerant system fails to reach the
specified vacuum, the system has a leak that must
be corrected. (Refer to 24 - HEATING & AIR CON-
DITIONING/PLUMBING - DIAGNOSIS AND
TESTING - REFRIGERANT SYSTEM LEAKS)
(b) If the refrigerant system maintains the spec-
ified vacuum for five minutes, restart the vacuum
pump, open the suction and discharge valves and
evacuate the system for an additional ten minutes.
(3) Close all of the valves, and turn off the charg-
ing station vacuum pump.
(4) The refrigerant system is now ready to be
charged with R-134a refrigerant. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE)
STANDARD PROCEDURE - REFRIGERANT
SYSTEM CHARGE
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)After the refrigerant system has been tested for
leaks and evacuated, a refrigerant charge can be
injected into the system. (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - SPECIFICA-
TIONS - CHARGE CAPACITY)
A R-134a refrigerant recovery/recycling/charging
station that meets SAE Standard J2210 must be
used to charge the refrigerant system with R-134a
refrigerant. Refer to the operating instructions sup-
plied by the equipment manufacturer for proper care
and use of this equipment.
SPECIFICATIONS
SPECIFICATIONS
The R-134a refrigerant system charge capacity for
this vehicle is: 0.907 kilograms (32 ounces).
A/C COMPRESSOR
DESCRIPTION
The air conditioning system uses a Sanden
SD7H15 seven cylinder, reciprocating wobble plate-
type compressor on all models. This compressor has a
fixed displacement of 150 cubic centimeters (9.375
cubic inches), and has both the suction and discharge
ports located on the cylinder head. A label identifying
the use of R-134a refrigerant is located on the com-
pressor.
DESCRIPTION - HIGH PRESSURE RELIEF
VALVE
A high pressure relief valve is located on the com-
pressor cylinder head, which is at the rear of the
compressor. This mechanical valve is designed to
vent refrigerant from the system to protect against
damage to the compressor and other system compo-
nents, caused by condenser air flow restriction or an
overcharge of refrigerant.
OPERATION
The compressor is driven by the engine through an
electric clutch, drive pulley and belt arrangement.
The compressor is lubricated by refrigerant oil that is
circulated throughout the refrigerant system with the
refrigerant.
The compressor draws in low-pressure refrigerant
vapor from the evaporator through its suction port. It
then compresses the refrigerant into a high-pressure,
high-temperature refrigerant vapor, which is then
pumped to the condenser through the compressor dis-
charge port.
The compressor cannot be repaired. If faulty or
damaged, the entire compressor assembly must be
24 - 46 PLUMBINGBR/BE
PLUMBING (Continued)

replaced. The compressor clutch, pulley and clutch
coil are available for service.
OPERATION - HIGH PRESSURE RELIEF VALVE
The high pressure relief valve vents the system
when a discharge pressure of 3445 to 4135 kPa (500
to 600 psi) or above is reached. The valve closes with
a minimum discharge pressure of 2756 kPa (400 psi)
is reached.
The high pressure relief valve vents only enough
refrigerant to reduce the system pressure, and then
re-seats itself. The majority of the refrigerant is con-
served in the system. If the valve vents refrigerant, it
does not mean the valve is faulty.
The high pressure relief valve is a factory-cali-
brated unit. The valve cannot be adjusted or
repaired, and must not be removed or otherwise dis-
turbed. The valve is only serviced as a part of the
compressor assembly.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
When investigating an air conditioning related
noise, you must first know the conditions under
which the noise occurs. These conditions include:
weather, vehicle speed, transmission in gear or neu-
tral, engine speed, engine operating temperature,
and any other special conditions. Noises that develop
during air conditioning operation can often be mis-
leading. For example: What sounds like a failed front
bearing or connecting rod, may be caused by loose
bolts, nuts, mounting brackets, or a loose compressor
clutch assembly.
Drive belts are speed sensitive. At different engine
speeds and depending upon belt tension, belts can
develop noises that are mistaken for a compressor
noise. Improper belt tension can cause a misleading
noise when the compressor clutch is engaged, which
may not occur when the compressor clutch is disen-
gaged. Check the serpentine drive belt condition and
tension before beginning this procedure(Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
DIAGNOSIS AND TESTING).
(1) Select a quiet area for testing. Duplicate the
complaint conditions as much as possible. Switch the
compressor on and off several times to clearly iden-
tify the compressor noise. Listen to the compressor
while the clutch is engaged and disengaged. Probe
the compressor with an engine stethoscope or a long
screwdriver with the handle held to your ear to bet-
ter localize the source of the noise.
(2) Loosen all of the compressor mounting hard-
ware and retighten. Tighten the compressor clutch
mounting nut. Be certain that the clutch coil is
mounted securely to the compressor, and that the
clutch plate and pulley are properly aligned and have
the correct air gap. (Refer to 24 - HEATING & AIRCONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH - INSTALLATION)
(3) To duplicate a high-ambient temperature condi-
tion (high head pressure), restrict the air flow
through the condenser. Install a manifold gauge set
to be certain that the discharge pressure does not
exceed 2760 kPa (400 psi).
(4) Check the refrigerant system plumbing for
incorrect routing, rubbing or interference, which can
cause unusual noises. Also check the refrigerant lines
for kinks or sharp bends that will restrict refrigerant
flow, which can cause noises. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - CAU-
TION)
(5) If the noise is from opening and closing of the
high pressure relief valve, recover, evacuate, and
recharge the refrigerant system. (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - STAN-
DARD PROCEDURE - REFRIGERANT RECOVERY)
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - STANDARD PROCEDURE - REFRIG-
ERANT SYSTEM EVACUATE) (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING -
STANDARD PROCEDURE - REFRIGERANT SYS-
TEM CHARGE) If the high pressure relief valve still
does not seat properly, replace the compressor.
(6) If the noise is from liquid slugging on the suc-
tion line, replace the accumulator. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/AC-
CUMULATOR - REMOVAL) Check the refrigerant oil
level and the refrigerant system charge. (Refer to 24
- HEATING & AIR CONDITIONING/PLUMBING/
REFRIGERANT OIL - STANDARD PROCEDURE -
REFRIGERANT OIL LEVEL) (Refer to 24 - HEAT-
ING & AIR CONDITIONING/PLUMBING - SPECI-
FICATIONS - CHARGE CAPACITY) If the liquid
slugging condition continues following accumulator
replacement, replace the compressor.
(7) If the noise continues, replace the compressor
and repeat Step 1.
REMOVAL
WARNING: REVIEW THE WARNINGS AND CAU-
TIONS IN THE FRONT OF THIS SECTION BEFORE
PERFORMING THE FOLLOWING OPERATION.
(Refer to 24 - HEATING & AIR CONDITIONING/
PLUMBING - WARNING) (Refer to 24 - HEATING &
AIR CONDITIONING/PLUMBING - CAUTION)
The compressor may be removed and repositioned
without disconnecting the refrigerant lines or dis-
charging the refrigerant system. Discharging is not
necessary if servicing the compressor clutch or clutch
coil, the engine, the cylinder head, or the generator.
(1) Recover the refrigerant from the refrigerant
system. (Refer to 24 - HEATING & AIR CONDI-
BR/BEPLUMBING 24 - 47
A/C COMPRESSOR (Continued)

EMISSIONS CONTROL
TABLE OF CONTENTS
page page
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - DIESEL.................1
DESCRIPTION - STATE DISPLAY TEST
MODE...............................1
DESCRIPTION - CIRCUIT ACTUATION TEST
MODE...............................2
DESCRIPTION - DIAGNOSTIC TROUBLE
CODES..............................2
DESCRIPTION - TASK MANAGER.........17
DESCRIPTION - MONITORED SYSTEMS . . . 17
DESCRIPTION - TRIP DEFINITION........19
DESCRIPTION - COMPONENT MONITORS -
GAS ENGINES.......................19DESCRIPTION - COMPONENT MONITORS -
DIESEL ENGINES.....................20
OPERATION
OPERATION - GAS ENGINES............20
OPERATION - DIESEL..................20
OPERATION - TASK MANAGER..........21
OPERATION - NON-MONITORED
CIRCUITS - GAS ENGINES..............24
OPERATION - NON-MONITORED
CIRCUITS - DIESEL....................24
AIR INJECTION.........................26
EVAPORATIVE EMISSIONS................32
EMISSIONS CONTROL
DESCRIPTION
DESCRIPTION - DIESEL
Two different modules are used for powertrain con-
trol with the diesel engine. The Powertrain Control
Module (PCM) is used primarily for charging system,
transmission, A/C compressor clutch operation and
speed control functions. The Engine Control Module
(ECM) is used to control thefuel and emissions
systems.The PCM is located in the right/rear of
engine compartment (Fig. 1). The ECM is bolted to
the left side of the engine cylinder block (Fig. 2).
DESCRIPTION - STATE DISPLAY TEST MODE
The switch inputs to the Powertrain Control Mod-
ule (PCM) have two recognized states; HIGH and
LOW. For this reason, the PCM cannot recognize the
difference between a selected switch position versus
an open circuit, a short circuit, or a defective switch.
If the State Display screen shows the change from
HIGH to LOW or LOW to HIGH, assume the entire
switch circuit to the PCM functions properly. Connectthe DRB scan tool to the data link connector and
access the state display screen. Then access either
State Display Inputs and Outputs or State Display
Sensors.
Fig. 1 Powertrain Control Module (PCM) Location
1 - PCM MOUNTING BOLTS (3)
2 - POWERTRAIN CONTROL MODULE (PCM)
3 - (3) 32±WAY CONNECTORS
BR/BEEMISSIONS CONTROL 25 - 1