2001 DODGE RAM change key battery

99,000 Miles (156 000 km)
²Change engine oil.
²Replace engine oil filter.
²Lubricate tie rod ends every 3,000 miles (5 000
km).
²Inspect front wheel bearings (4x2).
102,000 Miles (163 000 km)
²Change engine oil.
²Replace engine oil filter.
²Lubricate tie rod ends every 3,000 miles (5 000
km).
²Inspect front wheel bearings (4x4).
105,000 Miles (168 000 km)
²Change engine oil.
²Replace engine oil filter.
²Lubricate tie rod ends every 3,000 miles (5 000
km).
108,000 Miles (173 000 km)
²Change engine oil.
²Replace engine oil filter.
²Inspect engine air cleaner element and air
pump filter, replace as necessary.
²Drain and refill automatic transmission fluid.
Replace filter and adjust bands.³
²Drain and refill transfer case fluid (4x4).
²Change rear axle fluid.
²Change front axle fluid (4x4).
²Inspect brake linings.
²Flush and replace engine coolant if it has been
30,000 miles (48 000 km) since last change.
²Lubricate tie rod ends every 3,000 miles (5 000
km).
²Inspect front wheel bearings (4x4).
²Inspect front wheel bearings (4x2).
*Requires Service Reminder Indicator Light. If so
equipped, these parts are to be replaced at the indi-
cated mileage or when the service reminder indicator
light remains on continuously with the key in the
ªONº position, whichever occurs first.
³Off-the-highway operation, trailer towing, snow
plowing, prolonged operation with heavy loading,
especially in hot weather require the more frequent
transmission service indicated witha³inSchedule
ªBº. Perform these services if you usually operate
your Ram Truck under these conditions.
Inspection and service should also be performed
anytime a malfunction is observed or suspected.
DESCRIPTION - MAINTENANCE SCHEDULES
Ð 24±VALVE CUMMINS TURBO DIESEL
There are two maintenance schedules that show
proper service for the vehicle.First is ScheduleªA.ºIt lists all the scheduled
maintenance to be performed under ªnormalº operat-
ing conditions.
Second is ScheduleªB.ºIt is a schedule for vehicles
that are operated under the conditions listed at the
beginning of that schedule.
Use the schedule that best describes the driving
conditions.
Where time and mileage are listed, follow the
interval that occurs first.
At Each Stop For Fuel
²Check engine oil level and add as required.
²Check windshield washer solvent and add if
required.
²Clean windshield and wiper blades as required.
²Drain water from fuel filter.
Once A Month
²Check tire pressure and look for unusual wear
or damage.
²Inspect battery and clean and tighten terminals
as required.
²Check fluid levels of coolant reservoir, brake
master cylinder, power steering, and transmission.
Add fluid as required.
²Check all lights and all other electrical items for
correct operation.
²Check Filter Mindery. Replace air cleaner
element if necessary.
²Inspect and clean wiper blades. Replace if
required.
At Each Oil Change
²Inspect exhaust system.
²Inspect brake hoses.
²Adjust rear brakes.
²Rotate the tires at each oil change interval
shown at 7, 5000 miles (12 000 km) on schedule ªAº
or every other interval shown at 7,500 miles (12 000
km) on schedule ªBº.
²Check engine coolant level, hoses, and clamps.
²Lubricate steering linkage.
²Drain crankcase breather canister (if equipped).
EMISSION CONTROL SYSTEM MAINTENANCE
The scheduled emission maintenance listed inbold
typeon the Maintenance Schedules, must be done at
the mileage specified to assure the continued proper
functioning of the emission control system. These,
and all other maintenance services included in this
manual, should be done to provide the best vehicle
performance and reliability. More frequent mainte-
nance may be needed for vehicles in severe operating
conditions such as dusty areas and very short trip
driving.
0 - 22 LUBRICATION & MAINTENANCEBR/BE
MAINTENANCE SCHEDULES (Continued)

NOTE: ECM Outputs:
After inputs are received by the ECM, certain sen-
sors, switches and components are controlled or reg-
ulated by the ECM. These are consideredECM
Outputs.These outputs are for:
²CCD bus (+) circuits
²CCD bus (-) circuits
²CKP and APPS outputs to the PCM
²Data link connection for DRB scan tool
²Five volt sensor supply
²Fuel injection pump
²Fuel injection pump relay
²(FPCM) Fuel Pump Control Module
²Fuel transfer (lift) pump
²Intake manifold air heater relays #1 and #2 con-
trol circuits
²Malfunction indicator lamp (Check engine lamp)
²Oil pressure gauge/warning lamp
²PCM
²Wait-to-start warning lamp
²Water-In-Fuel (WIF) warning lamp
REMOVAL
The ECM is bolted to the engine block behind the
fuel filter (Fig. 16).
(1) Record any Diagnostic Trouble Codes (DTC's)
found in the PCM or ECM.To avoid possible voltage spike damage to either
the Powertrain Control Module (PCM) or ECM, igni-
tion key must be off, and negative battery cables
must be disconnected before unplugging ECM con-
nectors.
(2) Disconnect both negative battery cables at both
batteries.
(3) Remove 50±way electrical connector bolt at
ECM (Fig. 16). Note: Connector bolt is female 4mm
hex head. To remove bolt, use a ball-hex bit or ball-
hex screwdriver such as Snap-Ont4mm SDABM4
(5/32º may also be used). As bolt is being removed,
very carefully remove connector from ECM.
(4) Remove three ECM mounting bolts and remove
ECM from vehicle.
INSTALLATION
Do not apply paint to back of ECM. Poor ground
will result.
(1) Clean ECM mounting points at engine block.
(2) Position ECM to engine block and install 3
mounting bolts. Tighten bolts to 24 N´m (18 ft. lbs.).
(3) Check pin connectors in ECM and 50±way con-
nector for corrosion or damage. Repair as necessary.
(4) Clean pins in 50±way electrical connector with
a quick-dry electrical contact cleaner.
(5) Very carefully install 50±way connector to
ECM. Tighten connector hex bolt.
(6) Install battery cables.
(7)Turn key to ON position. Without starting
engine, slowly press throttle pedal to floor and
then slowly release. This step must be done
(one time) to ensure accelerator pedal position
sensor calibration has been learned by ECM. If
not done, possible DTC's may be set.
(8) Use DRB scan tool to erase any stored compan-
ion DTC's from PCM.
POWERTRAIN CONTROL
MODULE
DESCRIPTION - PCM
The Powertrain Control Module (PCM) is located
in the engine compartment (Fig. 17). The PCM is
referred to as JTEC.
DESCRIPTION - MODES OF OPERATION
As input signals to the Powertrain Control Module
(PCM) change, the PCM adjusts its response to the
output devices. For example, the PCM must calculate
different injector pulse width and ignition timing for
idle than it does for wide open throttle (WOT).
The PCM will operate in two different modes:
Open Loop and Closed Loop.
Fig. 16 Engine Control Module (ECM) Location and
Mounting
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - 50-WAY CONNECTOR
4 - FUEL TRANSFER PUMP
5 - MOUNTING BOLTS (3)
8E - 14 ELECTRONIC CONTROL MODULESBR/BE
ENGINE CONTROL MODULE (Continued)

²If both indicator lamps for a heated seat switch
operate, but the heated seat elements do not heat,
refer toHeated Seat Modulein Electronic Control
Modules for the location of the proper heated seat
module diagnosis and testing procedures. Also refer
to the Body Diagnostic Manual for additional diagno-
sis and testing procedures.
²If none of the indicator lamps for both heated
seat switches will operate and the heated seat ele-
ments for both seats do not heat, refer toHeated
Seat Relayin this section for the location of the
proper heated seat relay diagnosis and testing proce-
dures.
²If the an indicator lamp on either heated seat
switch remains illuminated after the heated seat has
been turned Off, refer toHeated Seat Modulein
Electronic Control Modules for the location of the
proper heated seat module diagnosis and testing pro-
cedures. Also refer to the Body Diagnostic Manual for
additional diagnosis and testing procedures.
DRIVER SEAT HEATER
SWITCH
DESCRIPTION
The heated seat switches used on vehicles with
this option are both mounted in a heated seat switch
bezel (Fig. 2), which replaces the standard equipmentcubby bin located in the lower right corner of the
instrument cluster bezel next to the radio receiver.
The two switches are snapped into the mounting
holes of the heated seat switch bezel, and the heated
seat switch bezel is secured with three screws to the
instrument panel. The mounts for the heated seat
switch bezel are concealed behind the instrument
cluster bezel. The two heated seat switches are iden-
tical in appearance and construction, except for the
location of a keyway in the single connector recepta-
cle on the back of each switch. The instrument panel
wire harness connectors for the heated seat switches
are keyed to match the connector receptacles on the
switches so that the two heated seat switches can
only be connected to the proper heated seat.
The momentary, bidirectional rocker-type heated
seat switch provides a resistor-multiplexed signal to
the heated seat module. Each switch has a center
neutral position and momentary Low and High posi-
tions so that both the driver and the front seat pas-
senger can select a preferred seat heating mode.
Each heated seat switch has two Light-Emitting
Diode (LED) indicator lamps, which indicate the
selected mode (Low or High) of the seat heater for
each seat and to provide diagnostic feedback for the
heated seat system. Each switch also has an incan-
descent bulb, which provides panel lamps dimmer
controlled back lighting of the switch nomenclature
when the headlamps or park lamps are turned on.
The two LED indicator lamps and the incandescent
bulb in each heated seat switch cannot be repaired. If
the indicator lamps or back lighting bulb are faulty
or damaged, the individual heated seat switch unit
must be replaced.
OPERATION
The heated seat switches receive battery current
through a fused ignition switch output (run) circuit
when the ignition switch is in the On position.
Depressing the heated seat switch rocker to its
momentary High or Low position provides a hard-
wired resistor multiplexed voltage request signal to
the heated seat module to power the heated seat ele-
ment of the selected seat and maintain the requested
temperature setting. If the heated seat switch is
depressed to a different position (Low or High) than
the currently selected state, the heated seat module
will change states to support the new selection. If a
heated seat switch is depressed a second time to the
same position as the currently selected state, the
heated seat module interprets the second input as a
request to turn the seat heater off. The heated seat
module will then turn the heated seat elements for
that seat off.
Fig. 2 Heated Seat Switches
1 - DRIVER SIDE SWITCH
2 - PASSENGER SIDE SWITCH
3 - INDICATOR LAMPS
4 - HEATED SEAT SWITCH BEZEL
BR/BEHEATED SEAT SYSTEM 8G - 7
HEATED SEAT SYSTEM (Continued)

INSTALLATION
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE AIRBAG SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE PERSONAL INJURY.
WARNING: WHEN REMOVING A DEPLOYED AIR-
BAG, RUBBER GLOVES, EYE PROTECTION, AND A
LONG-SLEEVED SHIRT SHOULD BE WORN. THERE
MAY BE DEPOSITS ON THE AIRBAG UNIT AND
OTHER INTERIOR SURFACES. IN LARGE DOSES,
THESE DEPOSITS MAY CAUSE IRRITATION TO THE
SKIN AND EYES.
WARNING: USE EXTREME CARE TO PREVENT ANY
FOREIGN MATERIAL FROM ENTERING THE PAS-
SENGER AIRBAG, OR BECOMING ENTRAPPED
BETWEEN THE PASSENGER AIRBAG CUSHION
AND THE PASSENGER AIRBAG DOOR. FAILURE TO
OBSERVE THIS WARNING COULD RESULT IN
OCCUPANT INJURIES UPON AIRBAG DEPLOY-
MENT.
WARNING: THE PASSENGER AIRBAG DOOR MUST
NEVER BE PAINTED. REPLACEMENT PASSENGER
AIRBAG DOORS ARE SERVICED IN THE ORIGINAL
COLORS. PAINT MAY CHANGE THE WAY IN WHICH
THE MATERIAL OF THE AIRBAG DOOR RESPONDS
TO AN AIRBAG DEPLOYMENT. FAILURE TO
OBSERVE THIS WARNING COULD RESULT IN
OCCUPANT INJURIES UPON AIRBAG DEPLOY-
MENT.
(1) Carefully inspect the five receptacle slots
around the top and sides of the passenger airbag
door opening of the instrument panel top cover.
Remove any of the small metal airbag door snap
retainers that did not remain on the molded airbag
door tabs during the removal procedure.
(2) If the removed passenger airbag module is
being reinstalled, install the metal snap retainers
recovered in Step 1onto the proper airbag door tabs.
Each of the five molded airbag door tabs must have a
snap retainer on it before it is installed in the instru-ment panel. New replacement passenger airbags
come with new airbag door snap retainers installed.
(3) Carefully position the passenger airbag onto
the instrument panel.
(4) Align the five tabs and retainers on the upper
edge and sides of the passenger airbag door with the
receptacles in the instrument panel top cover.
(5) Using hand pressure, press firmly on the pas-
senger airbag door over each of the tab and retainer
locations until each of them is fully engaged in its
receptacle. Be certain that each of the metal snap
retainers is in position on the airbag door tabs.
(6) Install and tighten the five screws that secure
the passenger airbag front and rear mounting brack-
ets to the instrument panel (Fig. 18). Tighten the
screws to 9 N´m (80 in. lbs.).
(7) Install and tighten the four screws that secure
the two plastic support brackets of the passenger air-
bag door panel outlet housing to the glove box open-
ing upper reinforcement. Tighten the screws to 2.2
N´m (20 in. lbs.).
(8) Reach through and above the glove box opening
to access and reconnect the passenger airbag pigtail
wire connector to the instrument panel wire harness
connector (Fig. 17). Be certain that the passenger air-
bag pigtail wire connector is fully engaged with and
latched to the instrument panel wire harness connec-
tor.
(9) Reinstall the glove box opening upper trim onto
the instrument panel. (Refer to 23 - BODY/INSTRU-
MENT PANEL/GLOVE BOX OPENING UPPER
TRIM - INSTALLATION).
(10) Reinstall the glove box onto the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - INSTALLATION).
(11) Do not reconnect the battery negative cable at
this time. The airbag system verification test proce-
dure should be performed following service of any
airbag system component. (Refer to 8 - ELECTRI-
CAL/RESTRAINTS - STANDARD PROCEDURE -
VERIFICATION TEST).
PASSENGER AIRBAG ON/OFF
SWITCH
DESCRIPTION
The passenger airbag on-off switch is standard
equipment on this model when it is not equipped
with a full size rear seat. This switch is a single pole,
single throw switch with a single integral red Light-
Emitting Diode (LED), and a non-coded key cylinder-
type actuator. The switch is located in the upper
right corner of instrument panel cluster bezel, near
the center of instrument panel to make the Off indi-
cator visible to all front seat occupants. When the
BR/BERESTRAINTS 8O - 23
PASSENGER AIRBAG (Continued)

switch is in its installed position, the only compo-
nents visible through the dedicated opening of the
cluster bezel are the switch face plate and nomencla-
ture, the key cylinder actuator, and a small round
lens with the text9Off9imprinted on it. The ªOnº
position of the switch is designated by text imprinted
upon the face plate of the switch, but is not illumi-
nated. The remainder of the switch is concealed
behind the switch face plate and the instrument
panel cluster bezel.
The passenger airbag on-off switch housing is con-
structed of molded plastic and has three integral
mounting tabs. These mounting tabs are used to
secure the switch to the back of the molded plastic
switch face plate with three small screws. The
molded plastic face plate also has three integral
mounting tabs that are used to secure the switch and
face plate unit to the instrument panel carrier with
three additional screws. Two short pigtail wires with
molded plastic connector insulators exit the back of
the switch housing and connect the switch to the
vehicle electrical system through two dedicated take
outs of the instrument panel wire harness. The har-
ness take outs are equipped with molded plastic con-
nector insulators that are keyed and latched to
ensure proper and secure switch electrical connec-
tions. The passenger airbag on/off switch cannot be
adjusted or repaired and, if faulty or damaged, the
switch must be replaced.
OPERATION
The passenger airbag on-off switch allows the cus-
tomer to turn the passenger airbag function On or
Off to accommodate certain uses of the right front
seating position where airbag protection may not be
desired. See the owner's manual in the vehicle glove
box for specific recommendations on when to enable
or disable the passenger airbag. The Off indicator of
the switch will be illuminated whenever the switch is
turned to the Off position. The ignition key is the
only key or object that should ever be inserted into
the switch. The on-off switch requires only a partial
key insertion to fully depress a spring-loaded locking
plunger. The spring-loaded locking plunger prevents
the user from leaving the key in the switch. The key
will be automatically ejected when force is not
applied. To actuate the passenger side airbag on/off
switch, insert the ignition key into the switch key
actuator far enough to fully depress the plunger and
rotate to the desired switch position. When the
switch key actuator is rotated to its clockwise stop
(the key actuator slot will be aligned with the Off
indicator lamp), the Off indicator is illuminated and
the passenger airbag is disabled. When the switch is
rotated to its counterclockwise stop (the key actuator
slot will be in a vertical position), the Off indicatorwill be extinguished and the passenger airbag is
enabled.
The passenger airbag switch is connected in series
between the Airbag Control Module (ACM) and the
passenger airbag inflator unit. When the switch is in
the On position, the switch connects the ACM
directly to the passenger airbag inflator. When the
switch is in the Off position it interrupts the inflator
circuits, but replaces the normal resistance in these
circuits with an internal resistor. Thus, the ACM is
unable to distinguish the mode of the switch and still
sends an electrical signal as though it were deploying
the passenger airbag when it detects a sufficient
impact. However, the switch position should not be
changed while the ignition switch is in the On posi-
tion, as the ACM may detect a fault, record a Diag-
nostic Trouble Code (DTC), and illuminate the Airbag
indicator in response to a momentary open it senses
in the passenger airbag inflator circuits as the on/off
switch changes states.
REMOVAL
WARNING: DISABLE THE AIRBAG SYSTEM
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. DISCON-
NECT AND ISOLATE THE BATTERY NEGATIVE
(GROUND) CABLE, THEN WAIT TWO MINUTES FOR
THE AIRBAG SYSTEM CAPACITOR TO DISCHARGE
BEFORE PERFORMING FURTHER DIAGNOSIS OR
SERVICE. THIS IS THE ONLY SURE WAY TO DIS-
ABLE THE AIRBAG SYSTEM. FAILURE TO TAKE
THE PROPER PRECAUTIONS COULD RESULT IN
ACCIDENTAL AIRBAG DEPLOYMENT AND POSSI-
BLE PERSONAL INJURY.
(1) Disconnect and isolate the battery negative
cable. If either of the airbags has not been deployed,
wait two minutes for the system capacitor to dis-
charge before further service.
(2) Remove the cluster bezel from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).
(3) Remove the glove box from the instrument
panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
GLOVE BOX - REMOVAL).
(4) Reach through the glove box opening to access
and disconnect the two passenger airbag on/off
switch pigtail wire harness connectors from the
instrument panel wire harness connectors. These
connectors are retained on a bracket located on the
inboard glove box opening reinforcement (Fig. 20).
(5) Remove the three screws that secure the pas-
senger airbag on/off switch face plate to the instru-
ment panel (Fig. 21).
8O - 24 RESTRAINTSBR/BE
PASSENGER AIRBAG ON/OFF SWITCH (Continued)

(8) Turn crankshaft and camshaft to line up with
keyway location in crankshaft sprocket and in cam-
shaft sprocket.
(9) Lift sprockets and chain (keep sprockets tight
against the chain in position as described).
(10) Slide both sprockets evenly over their respec-
tive shafts and use a straightedge to check alignment
of timing marks (Fig. 22).
(11) Install the camshaft bolt/cup washer. Tighten
bolt to 68 N´m (50 ft. lbs.) torque.
(12) Measure camshaft end play (Fig. 23). (Refer to
9 - ENGINE - SPECIFICATIONS) for proper clear-
ance. If not within limits, install a new timing chain
tensioner.
(13) Each tappet reused must be installed in the
same position at which it was removed.When cam-
shaft is replaced, all of the tappets must be
replaced.Install hydraulic tappets (Refer to 9 -
ENGINE/ENGINE BLOCK/HYDRAULIC LIFTERS
(CAM IN BLOCK) - INSTALLATION).
(14) Install timing chain cover (Refer to 9 -
ENGINE/VALVE TIMING/TIMING BELT / CHAIN
COVER(S) - INSTALLATION).
(15) Install intake manifold (Refer to 9 - ENGINE/
MANIFOLDS/INTAKE MANIFOLD - INSTALLA-
TION).
(16) Install distributor.
(17) Install cylinder head covers (Refer to 9 -
ENGINE/CYLINDER HEAD/CYLINDER HEAD
COVER(S) - INSTALLATION).
(18) Install radiator (Refer to 7 - COOLING/EN-
GINE/RADIATOR - INSTALLATION).
(19) Fill cooling system (Refer to 7 - COOLING -
STANDARD PROCEDURE).
(20) Connect battery negative cable.
(21) Start engine and check for leaks.
CONNECTING ROD BEARINGS
STANDARD PROCEDURE-CONNECTING ROD
BEARING FITTING
Fit all rods on a bank until completed. DO NOT
alternate from one bank to another, because connect-
ing rods and pistons are not interchangeable from
one bank to another.
The bearing caps are not interchangeable and
should be marked at removal to ensure correct
assembly.
Each bearing cap has a small V-groove across the
parting face. When installing the lower bearing shell,
be certain that the V-groove in the shell is in line
with the V-groove in the cap. This provides lubrica-
tion of the cylinder wall in the opposite bank.The bearing shells must be installed so that the
tangs are in the machined grooves in the rods and
caps.
Limits of taper or out-of-round on any crankshaft
journals should be held to 0.025 mm (0.001 in.).
Bearings are available in 0.025 mm (0.001 in.), 0.051
mm (0.002 in.), 0.076 mm (0.003 in.), 0.254 mm
(0.010 in.) and 0.305 mm (0.012 in.) undersize.
Install the bearings in pairs. DO NOT use a new
bearing half with an old bearing half. DO NOT
file the rods or bearing caps.
CRANKSHAFT
DESCRIPTION
The crankshaft (Fig. 24) is of a forged steel splayed
type design, with four main bearing journals.The
crankshaft is located at the bottom of the engine
block and is held in place with four main bearing
caps.
OPERATION
The crankshaft transfers force generated by com-
bustion within the cylinder bores to the flywheel or
flexplate.
REMOVAL
(1) Remove the oil pan (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - REMOVAL).
(2) Remove the oil pump (Refer to 9 - ENGINE/
LUBRICATION/OIL PUMP - REMOVAL).
(3) Identify bearing caps before removal. Remove
bearing caps and bearings one at a time.
(4) Lift the crankshaft out of the block.
Fig. 24 CrankshaftÐ3.9L Engine
BR/BEENGINE 3.9L 9 - 31
CAMSHAFT & BEARINGS (IN BLOCK) (Continued)

(1) Be sure fuel tank contains fuel before starting
test. If tank is empty or near empty, amperage read-
ings will be incorrect.
(2) Obtain LCS adapter.
(3) Plug cable from LCS adapter into DRB scan
tool at SET 1 receptacle.
(4) Plug DRB into vehicle 16±way connector (data
link connector).
(5) Connect (-) and (+) test cable leads into LCS
adapter receptacles. Use10 amp (10A +)receptacle
and common (-) receptacles.
(6) Gain access to MAIN MENU on DRB screen.
(7) Press DVOM button on DRB.
(8) Using left/right arrow keys, highlight CHAN-
NEL 1 function on DRB screen.
(9) Press ENTER three times.
(10) Using up/down arrow keys, highlight RANGE
on DRB screen (screen will default to 2 amp scale).
(11) Press ENTER to change 2 amp scale to 10
amp scale.This step must be done to prevent
damage to DRB scan tool or LCS adapter
(blown fuse).
(12) Remove cover from Power Distribution Center
(PDC).
(13) Remove fuel pump relay from PDC. Refer to
label on PDC cover for relay location.
WARNING: BEFORE PROCEEDING TO NEXT STEP,
NOTE THE FUEL PUMP WILL BE ACTIVATED AND
SYSTEM PRESSURE WILL BE PRESENT. THIS WILL
OCCUR AFTER CONNECTING TEST LEADS FROM
LCS ADAPTER INTO FUEL PUMP RELAY CAVITIES.
THE FUEL PUMP WILL OPERATE EVEN WITH IGNI-
TION KEY IN OFF POSITION. BEFORE ATTACHING
TEST LEADS, BE SURE ALL FUEL LINES AND
FUEL SYSTEM COMPONENTS ARE CONNECTED.
CAUTION: To prevent possible damage to the vehi-
cle electrical system and LCS adapter, the test
leads must be connected into relay cavities exactly
as shown in following steps.
Depending upon vehicle model, year or engine con-
figuration, three different types of relays may be
used: Type-1, type-2 and type±3.
(14) If equipped withtype±1 relay(Fig. 13),
attach test leads from LCS adapter into PDC relay
cavities number 30 and 87. For location of these cav-
ities, refer to numbers stamped to bottom of relay
(Fig. 13).
(15) If equipped withtype±2 relay(Fig. 14),
attach test leads from LCS adapter into PDC relay
cavities number 30 and 87. For location of these cav-
ities, refer to numbers stamped to bottom of relay
(Fig. 14).(16) If equipped withtype±3 relay(Fig. 15),
attach test leads from LCS adapter into PDC relay
cavities number 3 and 5. For location of these cavi-
ties, refer to numbers stamped to bottom of relay
(Fig. 15).
Fig. 13 FUEL PUMP RELAY - TYPE 1
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
Fig. 14 FUEL PUMP RELAY - TYPE 2
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
BR/BEFUEL DELIVERY - GASOLINE 14 - 11
FUEL PUMP (Continued)

(5) Install new plastic tie strap (Fig. 28) to secure
sensor pigtail harness to side of engine block. Thread
tie strap through casting hole on cylinder block.
FUEL PUMP RELAY
DESCRIPTION
The 5±pin, 12±volt, fuel pump relay is located in
the Power Distribution Center (PDC). Refer to the
label on the PDC cover for relay location.
OPERATION
The Powertrain Control Module (PCM) energizes
the electric fuel pump through the fuel pump relay.
The fuel pump relay is energized by first applying
battery voltage to it when the ignition key is turned
ON, and then applying a ground signal to the relay
from the PCM.
Whenever the ignition key is turned ON, the elec-
tric fuel pump will operate. But, the PCM will shut-
down the ground circuit to the fuel pump relay in
approximately 1±3 seconds unless the engine is oper-
ating or the starter motor is engaged.
REMOVAL
The fuel pump relay is located in the Power Distri-
bution Center (PDC) (Fig. 31). Refer to label on PDC
cover for relay location.
(1) Remove PDC cover.
(2) Remove relay from PDC.
(3) Check condition of relay terminals and PDC
connector terminals for damage or corrosion. Repair
if necessary before installing relay.
(4) Check for pin height (pin height should be the
same for all terminals within the PDC connector).
Repair if necessary before installing relay.
INSTALLATION
The fuel pump relay is located in the Power Distri-
bution Center (PDC) (Fig. 31). Refer to label on PDC
cover for relay location.
(1) Install relay to PDC.
(2) Install cover to PDC.
IDLE AIR CONTROL MOTOR
DESCRIPTION
The IAC stepper motor is mounted to the throttle
body, and regulates the amount of air bypassing the
control of the throttle plate. As engine loads and
ambient temperatures change, engine rpm changes.
A pintle on the IAC stepper motor protrudes into a
passage in the throttle body, controlling air flow
through the passage. The IAC is controlled by the
Powertrain Control Module (PCM) to maintain the
target engine idle speed.
OPERATION
At idle, engine speed can be increased by retract-
ing the IAC motor pintle and allowing more air to
pass through the port, or it can be decreased by
restricting the passage with the pintle and diminish-
ing the amount of air bypassing the throttle plate.
The IAC is called a stepper motor because it is
moved (rotated) in steps, or increments. Opening the
IAC opens an air passage around the throttle blade
which increases RPM.
The PCM uses the IAC motor to control idle speed
(along with timing) and to reach a desired MAP dur-
ing decel (keep engine from stalling).
The IAC motor has 4 wires with 4 circuits. Two of
the wires are for 12 volts and ground to supply electri-
cal current to the motor windings to operate the step-
per motor in one direction. The other 2 wires are also
for 12 volts and ground to supply electrical current to
operate the stepper motor in the opposite direction.
To make the IAC go in the opposite direction, the
PCM just reverses polarity on both windings. If only
1 wire is open, the IAC can only be moved 1 step
(increment) in either direction. To keep the IAC
motor in position when no movement is needed, the
PCM will energize both windings at the same time.
This locks the IAC motor in place.
In the IAC motor system, the PCM will count
every step that the motor is moved. This allows the
PCM to determine the motor pintle position. If the
memory is cleared, the PCM no longer knows the
position of the pintle. So at the first key ON, the
PCM drives the IAC motor closed, regardless of
where it was before. This zeros the counter. From
this point the PCM will back out the IAC motor and
keep track of its position again.
Fig. 31 Power Distribution Center (PDC)
1 - POWER DISTRIBUTION CENTER (PDC)
BR/BEFUEL INJECTION - GASOLINE 14 - 41
CRANKSHAFT POSITION SENSOR (Continued)