fuse CHRYSLER CARAVAN 2002 Service Manual

(4) The coil ground terminal (85) is connected to
the electromagnet in the relay. It receives battery
feed to energize the accessory relay when the ignition
switch is in the Accessory or On positions. Turn the
ignition switch to the On position. Check for battery
voltage at the fused ignition switch output (acc/run)
circuit cavity for relay terminal 85 in the IPM recep-
tacle for the accessory relay. If OK, go to Step 5. If
not OK, repair the open fused ignition switch output
(acc/run) circuit to the ignition switch as required.
(5) The coil battery terminal (86) is connected to
the electromagnet in the relay. The IPM cavity for
this terminal should have continuity to ground at all
times. If not OK, repair the open ground circuit to
ground as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the Integrated Power Module (IPM)
cover from the IPM.
(3) Remove the accessory relay from the IPM.
Refer to the IPM cover for relay location.
INSTALLATION
(1) Position the accessory relay in the proper
receptacle in the Integrated Power Module (IPM).
(2) Push in firmly on the accessory relay until the
terminals are fully seated in the terminal cavities in
the IPM receptacle.
(3) Install the IPM cover.
(4) Reconnect the battery negative cable.
INTEGRATED POWER MODULE
DESCRIPTION
The Integrated Power Module (IPM) is a combina-
tion of the Power Distribution Center (PDC) and the
Front Control Module (FCM). The IPM is located in
the engine compartment, next to the battery on this
model (Fig. 2). The power distribution center mates
directly with the Front Control Module (FCM) to
form the IPM Fuse and Relay Center. The power dis-
tribution center (PDC) is a printed circuit board
based module that contains fuses and relays, while
the front control module contains the electronics con-
trolling the IPM and other functions. This IPM con-
nects directly to the battery positive via a four pin
connector. The ground connection is via two other
connectors. The IPM provides the primary means of
voltage distribution and protection for the entire
vehicle.
The molded plastic IPM housing includes a base
and cover. The IPM cover is easily opened or removed
for service access by squeezing the two marked coverlatches and has a fuse and relay layout map integral
to the inside surface of the cover. This IPM housing
base and cover are secured in place by an IPM
mounting bracket. This mounting bracket is designed
to allow the IPM to rotate counter-clockwise once the
locking tab is disengaged. The IPM mounting bracket
is secured in place by bolts threaded into the left
front wheel house.
Replaceable components of the IPM assembly are
broken down into the following components: the
Power Distribution Center (PDC) (without fuses or
relays), the IPM cover, the Front Control Module
(FCM), the IPM mounting bracket, IPM bracket
retaining clips and the IPM assembly which includes
the power distribution center, the cover and FCM.
Refer to the Front Control Module in the Elec-
tronic Control Module sectionof this service
manual for information on the FCM.
OPERATION
All of the current from the battery and the gener-
ator output enters the Integrated Power Module
(IPM) via a four- pin connector on the bottom of the
module. The IPM cover is unlatched and opened or
removed to access the fuses or relays. Internal con-
nections of all of the power distribution center cir-
cuits is accomplished by a combination of bus bars
and a printed circuit board. Refer to the Wiring sec-
Fig. 2 BATTERY THERMAL GUARD
1 - BATTERY THERMAL GUARD
2 - INTEGRATED POWER MODULE
3 - FRONT CONTROL MODULE
RS8W-97 POWER DISTRIBUTION SYSTEM8W-97-3
ACCESSORY RELAY (Continued)
ProCarManuals.com

tion of the service manual for complete IPM circuit
schematics.
REMOVAL
(1) Disconnect the negative and positive battery
cables.
(2) Remove the battery thermal guard from the
vehicle. Refer to the Battery section for the proce-
dure.
(3) Remove the battery from the vehicle. Refer to
the Battery section for the procedure.
(4) Using a flat-bladed screwdriver, twist the Inte-
grated Power Module (IPM) bracket retaining latch
outward to free the intelligent power module from its
mounting bracket (Fig. 3).
(5) Rotate the IPM counter-clockwise to access and
disconnect the various electrical connectors (Fig. 4).
(6) Free the IPM from its mounting bracket by
removing the IPM bracket clips from the hinge. A
screwdriver slipped up from under the hinge will free
the clips.
INSTALLATION
(1) Snap the left side of the Integrated Power Mod-
ule (IPM) housing in its mounting bracket and con-
nect the various electrical connectors. Care must be
taken that the Connector Positive Assurance (CPA)
on the five-pin B+ connector is positively engaged to
prevent generating a Diagnostic Trouble Code (DTC).
NOTE: IPM electrical connectors are color coded to
ease location reference.(2) Being certain no wires are stressed or pinched,
rotate the IPM clock-wise until secured in mounting
bracket. An audible click may be heard.
(3) Install the battery in the vehicle. Refer to the
Battery section for the procedure.
(4) Install the battery thermal guard in the vehi-
cle. Refer to the Battery section for the procedure.
(5)
Connect the negative and positive battery cables.
(6) Using a diagnostic scan tool, check for any
stored diagnostic trouble codes and correct, check
that all vehicle options are operational before return-
ing the vehicle to service.
IOD FUSE
DESCRIPTION
All vehicles are equipped with an Ignition-Off
Draw (IOD) fuse that is removed from its normal
cavity in the Integrated Power Module (IPM) when
the vehicle is shipped from the factory. Dealer per-
sonnel are to remove the IOD fuse from the storage
location and install it into the IPM fuse cavity
marked IOD as part of the preparation procedures
performed just prior to new vehicle delivery.
The IPM has a molded plastic cover that can be
removed to provide service access to all of the fuses
and relays in the IPM. An integral latch and hinges
are molded into the IPM cover for easy removal. A
fuse layout map is integral to the underside of the
IPM cover to ensure proper fuse and relay identifica-
Fig. 3 RELEASING INTEGRATED POWER MODULE
FROM ITS MOUNTING BRACKET
Fig. 4 DISCONNECTING IPM
1 - INTEGRATED POWER MODULE FUSE & RELAY CENTER
8W - 97 - 4 8W-97 POWER DISTRIBUTION SYSTEMRS
INTEGRATED POWER MODULE (Continued)
ProCarManuals.com

tion. The IOD fuse is a 15 ampere blade-type car-
tridge fuse and, when removed, it is stored in a fuse
cavity adjacent to the washer fuse within the IPM.
OPERATION
The term ignition-off draw identifies a normal con-
dition where power is being drained from the battery
with the ignition switch in the Off position. The IOD
fuse feeds the memory and sleep mode functions for
some of the electronic modules in the vehicle as well
as various other accessories that require battery cur-
rent when the ignition switch is in the Off position,
including the clock. The only reason the IOD fuse is
removed is to reduce the normal IOD of the vehicle
electrical system during new vehicle transportation
and pre-delivery storage to reduce battery depletion,
while still allowing vehicle operation so that the
vehicle can be loaded, unloaded and moved as needed
by both vehicle transportation company and dealer
personnel.
The IOD fuse is removed from the IPM fuse cavity
when the vehicle is shipped from the assembly plant.
Dealer personnel must install the IOD fuse when the
vehicle is being prepared for delivery in order to
restore full electrical system operation. Once the
vehicle is prepared for delivery, the IOD function of
this fuse becomes transparent and the fuse that has
been assigned the IOD designation becomes only
another Fused B(+) circuit fuse. The IOD fuse serves
no useful purpose to the dealer technician in the ser-
vice or diagnosis of any vehicle system or condition,
other than the same purpose as that of any other
standard circuit protection device.
The IOD fuse can be used by the vehicle owner as
a convenient means of reducing battery depletion
when a vehicle is to be stored for periods not to
exceed about thirty days. However, it must be
remembered that removing the IOD fuse will not
eliminate IOD, but only reduce this normal condition.
If a vehicle will be stored for more than about thirty
days, the battery negative cable should be discon-
nected to eliminate normal IOD; and, the battery
should be tested and recharged at regular intervals
during the vehicle storage period to prevent the bat-
tery from becoming discharged or damaged. Refer to
Battery Systemfor additional service information.
REMOVAL
(1) Turn the ignition switch to the Off position.
(2) Unlatch and open the cover of the intelligent
power module.
(3) Remove the IOD fuse from fuse location
markedIODof the Integrated Power Module (IPM).
(4) Store the removed IOD fuse by installing it in
the unused fuse storage markedSPAREof the IPM.
(5) Close and latch the IPM.
INSTALLATION
(1) Be certain the ignition switch is in the Off posi-
tion.
(2) Unlatch and open the cover of the Integrated
Power Module (IPM).
(3) Remove the stored 15 amp IOD fuse from fuse
storage markedSPAREof the IPM.
(4) Use a thumb to press the IOD fuse firmly down
into IPM fuse cavity markedIOD.
(5) Close and latch the IPM cover.
POWER OUTLET
DESCRIPTION
Accessory power outlets are standard equipment on
this model. Two power outlets are installed in the
instrument panel center lower bezel, which is located
near the bottom of the instrument panel center stack
area. Two additional power outlets are also incorpo-
rated into the vehicle, one on the left rear C-pillar
trim and the other in the center console, if equipped.
The power outlets bases are secured by a snap fit in
the appropriate bezels. A hinged plug flips closed to
conceal and protect the power outlet base when the
power outlet is not being used.
The power outlet receptacle unit and the power
outlet plugs are each available for service replace-
ment.
OPERATION
The power outlet base or receptacle shell is con-
nected to ground, and an insulated contact in the
bottom of the shell is connected to battery current.
The power outlet on the instrument panel marked
with a battery receives battery voltage from a fuse in
the Integrated Power Module (IPM) at all times. The
other power outlet on the instrument panel marked
with a key receives battery voltage only when the
key is in the on position.
The power outlet located in the center console
receives battery voltage all the time when positioned
between thefront seatsand key-on voltage when
positioned between therear seats. The power outlet
located on the C-pillar receives battery voltage only
when the key is in the on position.
DIAGNOSIS AND TESTING
DIAGNOSIS & TESTING - POWER OUTLET
For complete circuit diagrams, refer toCigar
Lighter/Power Outletin Wiring Diagrams.
RS8W-97 POWER DISTRIBUTION SYSTEM8W-97-5
IOD FUSE (Continued)
ProCarManuals.com

WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO RESTRAINTS BEFORE ATTEMPT-
ING ANY STEERING WHEEL, STEERING COLUMN,
SEAT OR INSTRUMENT PANEL COMPONENT DIAG-
NOSIS OR SERVICE. FAILURE TO TAKE THE
PROPER PRECAUTIONS COULD RESULT IN ACCI-
DENTAL AIRBAG DEPLOYMENT AND POSSIBLE
PERSONAL INJURY.
(1) Check the fused B(+) fuse in the Integrated
Power Module (IPM). If OK, go to Step 2. If not OK,
repair the shorted circuit or component as required
and replace the faulty fuse.
(2) Check for battery voltage at the fused B(+) fuse
in the IPM. If OK, go to Step 3. If not OK, repair the
open fused B(+) circuit to the IPM fuse as required.
(3)
Open the power outlet door. Check for continuity
between the inside circumference of the power outlet
receptacle and a good ground. There should be continu-
ity. If OK, go to Step 4. If not OK, go to Step 5.
(4) Check for battery voltage at the insulated con-
tact located at the back of the power outlet recepta-
cle. If not OK, go to Step 5.
(5) Disconnect and isolate the battery negative
cable. Remove the appropriate bezel. Check for conti-
nuity between the ground circuit cavity of the power
outlet wire harness connector and a good ground.
There should be continuity. If OK, go to Step 6. If not
OK, repair the open ground circuit to ground as
required.
(6) Connect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
power outlet wire harness connector. If OK, replace
the faulty power outlet receptacle. If not OK, repair
the open fused B(+) circuit to the IPM fuse as
required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Look inside and note position of the retaining
bosses (Fig. 5).
(3) Using external snap ring pliers with 90 degree
tips. Insert pliers with tips against bosses and
squeeze forcing bosses out of base.
(4) Pull out the base through mounting ring by
gently rocking pliers. A tool can be made to do the
same. Refer to (Fig. 6).
(5) Disconnect the base wires.
(6) Set base aside. Remove light ring and discon-
nect wire.
INSTALLATION
(1) Position the mounting ring on the instrument
panel and feed the wires through the ring. Index the
cap and the mounting ring with the index tab at the9 o'clock position to the key in the instrument panel.
Install the ring.
(2) Connect the wires to the base. Orientate the
base alignment rib at the 11 o'clock position to mate
the groove in the mounting ring to the base.
(3) Push the base into the bezel until it locks in
place.
(4) Check operation of outlet or element and
install the 12 volt outlet cap.
Fig. 5 Outlet Base Removal
1 - RETAINING BOSSES-ENGAGE PLIERS HERE
2 - PARTIALLY REMOVED
3 - EXTERNAL SNAP-RING PLIERS
4 - PULL BASE OUT-THROUGH MOUNTING RING
Fig. 6 Tool For Outlet Removal
1 - 2.5MM (3/32 INS.)
2 - WELD
3 - 100MM (4 INS.)
4 - 22.25 TO 22.45MM (7/8 TO 57/64 INS.)
8W - 97 - 6 8W-97 POWER DISTRIBUTION SYSTEMRS
POWER OUTLET (Continued)
ProCarManuals.com

FUEL PUMP RELAY
DESCRIPTION
The fuel pump relay is located in the PDC. The
inside top of the PDC cover has a label showing relay
and fuse location.
OPERATION
The fuel pump relay supplies battery voltage to the
fuel pump. A buss bar in the Power Distribution Cen-
ter (PDC) supplies voltage to the solenoid side and
contact side of the relay. The fuel pump relay power
circuit contains a fuse between the buss bar in the
PDC and the relay. The fuse is located in the PDC.
Refer to the Wiring Diagrams for circuit information.
The PCM controls the fuel pump relay by switch-
ing the ground path for the solenoid side of the relay
on and off. The PCM turns the ground path off when
the ignition switch is in the Off position. When the
ignition switch is in the On position, the PCM ener-
gizes the fuel pump. If the crankshaft position sensor
does not detect engine rotation, the PCM de-ener-
gizes the relay after approximately one second.
IDLE AIR CONTROL MOTOR
DESCRIPTION
The idle air control motor is mounted on the throt-
tle body. The PCM operates the idle air control motor
(Fig. 14) or (Fig. 15).
OPERATION
The PCM adjusts engine idle speed through the
idle air control motor to compensate for engine load,
coolant temperature or barometric pressure changes.
The throttle body has an air bypass passage that
provides air for the engine during closed throttle idle.
The idle air control motor pintle protrudes into the
air bypass passage and regulates air flow through it.
The PCM adjusts engine idle speed by moving the
IAC motor pintle in and out of the bypass passage. The
adjustments are based on inputs the PCM receives.
The inputs are from the throttle position sensor, crank-
shaft position sensor, coolant temperature sensor, MAP
sensor, vehicle speed sensor and various switch opera-
tions (brake, park/neutral, air conditioning).
When engine rpm is above idle speed, the IAC is
used for the following functions:
²Off-idle dashpot
²Deceleration air flow control
²A/C compressor load control (also opens the pas-
sage slightly before the compressor is engaged so
that the engine rpm does not dip down when the
compressor engages)
Target Idle
Target idle is determined by the following inputs:
²Gear position
²ECT Sensor
²Battery voltage
²Ambient/Battery Temperature Sensor
²VSS
²TPS
²MAP Sensor
Fig. 14 TPS/IAC 2.4L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
Fig. 15 TPS/IAC 3.3/3.8L
1 - Idle Air Control Motor
2 - Throttle Position Sensor
RSFUEL INJECTION14-27
ProCarManuals.com

TRANSMISSION CONTROL
RELAY
DESCRIPTION
The transmission control relay (Fig. 336) is located
in the Intelligent Power Module (IPM), which is
located on the left side of the engine compartment
between the battery and left fender.
OPERATION
The relay is supplied fused B+ voltage, energized by
the TCM, and is used to supply power to the solenoid
pack when the transmission is in normal operating mode.
When the relay is ªoffº, no power is supplied to the sole-
noid pack and the transmission is in ªlimp-inº mode.
After a controller reset (ignition key turned to the ªrunº
position or after cranking engine), the TCM energizes the
relay. Prior to this, the TCM verifies that the contacts
are open by checking for no voltage at the switched bat-
tery terminals. After this is verified, the voltage at the
solenoid pack pressure switches is checked. After the
relay is energized, the TCM monitors the terminals to
verify that the voltage is greater than 3 volts.
TRANSMISSION RANGE
SENSOR
DESCRIPTION
The Transmission Range Sensor (TRS) is mounted
to the top of the valve body inside the transaxle andcan only be serviced by removing the valve body. The
electrical connector extends through the transaxle
case (Fig. 337) .
The Transmission Range Sensor (TRS) has four
switch contacts that monitor shift lever position and
send the information to the TCM.
The TRS also has an integrated temperature sen-
sor (thermistor) that communicates transaxle tem-
perature to the TCM and PCM (Fig. 338) .
Fig. 336 Transmission Control Relay Location
1 - TRANSMISSION CONTROL RELAY
2 - LEFT FENDER
3 - INTELLIGENT POWER MODULE (IPM)
4 - BATTERY
Fig. 337 Transmission Range Sensor (TRS)
Location
1 - TRANSMISSION RANGE SENSOR
Fig. 338 Transmission Temperature Sensor
1 - TRANSMISSION RANGE SENSOR
2 - TEMPERATURE SENSOR
RS41TE AUTOMATIC TRANSAXLE21 - 291
ProCarManuals.com

(5) Install and tighten the three screws that secure
the heater core shield to the left end of the heater/air
conditioner housing. Tighten the screws to 2 N´m (17
in. lbs.).
(6) Reinstall the silencer under the driver side end
of the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/INSTRUMENT PANEL
SILENCER - INSTALLATION).
(7) Reconnect the battery negative cable.
(8) Perform the heater-A/C control calibration pro-
cedure. (Refer to 24 - HEATING & AIR CONDITION-
ING/CONTROLS - FRONT/A/C-HEATER CONTROL
- STANDARD PROCEDURE - HEATER-A/C CON-
TROL CALIBRATION).
BLOWER MOTOR RELAY
DESCRIPTION
The blower motor relay (Fig. 6) is a International
Standards Organization (ISO) mini-relay. Relays con-
forming to the ISO specifications have common phys-
ical dimensions, current capacities, terminal
patterns, and terminal functions. The ISO mini-relay
terminal functions are the same as a conventional
ISO relay. However, the ISO mini-relay terminal pat-
tern (or footprint) is different, the current capacity is
lower, and the physical dimensions are smaller than
those of the conventional ISO relay. The blower
motor relay is located in the Intelligent Power Mod-
ule (IPM), which is in the engine compartment near
the battery. See the fuse and relay layout mapmolded into the inner surface of the IPM cover for
blower motor relay identification and location.
The black, molded plastic case is the most visible
component of the blower motor relay. Five male
spade-type terminals extend from the bottom of the
base to connect the relay to the vehicle electrical sys-
tem, and the ISO designation for each terminal is
molded into the base adjacent to each terminal.
OPERATION
The blower motor relay is an electromechanical
switch that uses a low current input from the Front
Control Module (FCM) to control the high current
output to the blower motor resistor (manual heater-
A/C control) or blower power module (ATC control).
The movable common feed contact point is held
against the fixed normally closed contact point by
spring pressure. When the relay coil is energized, an
electromagnetic field is produced by the coil wind-
ings. This electromagnetic field draws the movable
relay contact point away from the fixed normally
closed contact point, and holds it against the fixed
normally open contact point. When the relay coil is
de-energized, spring pressure returns the movable
contact point back against the fixed normally closed
contact point. The resistor or diode is connected in
parallel with the relay coil in the relay, and helps to
dissipate voltage spikes and electromagnetic interfer-
ence that can be generated as the electromagnetic
field of the relay coil collapses.
The blower motor relay terminals are connected to
the vehicle electrical system through a receptacle in
the Intelligent Power Module (IPM). The inputs and
outputs of the blower motor relay include:
²The common feed terminal (30) receives a bat-
tery current input from the battery through a B(+)
circuit at all times.
²The coil ground terminal (85) receives a ground
input through the front/rear blower motor relay con-
trol circuit only when the FCM electronically pulls
the control circuit to ground.
²The coil battery terminal (86) receives a battery
current input from the battery through a B(+) circuit
at all times.
²The normally open terminal (87) provides a bat-
tery current output to the blower motor resistor
(manual heater-A/C control) or blower power module
(automatic heater-A/C control) through a fuse in the
IPM on the fused front blower motor relay output cir-
cuit only when the blower motor relay coil is ener-
gized.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but provides
a battery current output only when the blower motor
relay coil is de-energized.
Fig. 6 Blower Motor Relay
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
RSCONTROLS - FRONT24-13
BLEND DOOR ACTUATOR (Continued)
ProCarManuals.com

Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices, and grounds.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RELAY
The front blower motor relay (Fig. 7) is located in
the Intelligent Power Module (IPM), which is in the
engine compartment near the battery. See the fuse
and relay layout map molded into the inner surface
of the IPM cover for front blower motor relay identi-
fication and location. Remove the relay from the IPM
to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   5 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, use a DRBIIItscan tool to perform
further diagnosis of the relay circuits. Refer to the
appropriate diagnostic information. If not OK,
replace the faulty relay.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unlatch and remove the cover from the Intelli-
gent Power Module (IPM) (Fig. 8).
(3) See the fuse and relay layout map molded into
the inner surface of the IPM cover for front blower
motor relay identification and location.
(4) Remove the front blower motor relay from the
IPM by pulling the relay straight up.
INSTALLATION
(1) See the fuse and relay layout map molded into
the inner surface of the Intelligent Power Module
(IPM) cover for front blower motor relay identifica-
tion and location.
(2) Position the front blower motor relay to the
proper receptacle in the IPM.
(3) Align the front blower motor relay terminals
with the terminal cavities in the IPM relay recepta-
cle.
(4) Push down firmly on the front blower motor
relay until the terminals are fully seated in the ter-
minal cavities in the IPM receptacle.
(5) Install and latch the cover onto the IPM.
(6) Reconnect the battery negative cable.
Fig. 7 Blower Motor Relay - Terminal Legend
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
Fig. 8 Intelligent Power Module
1 - BATTERY THERMAL GUARD
2 - INTELLIGENT POWER MODULE
3 - FRONT CONTROL MODULE
24 - 14 CONTROLS - FRONTRS
BLOWER MOTOR RELAY (Continued)
ProCarManuals.com

(2) If the a/c compressor clutch still will not
engage, disconnect the headlamp and dash wire har-
ness connector for the A/C pressure transducer and
check for battery current at the connector with the
engine running and the heater-A/C control set to the
A/C mode. If OK, go to TESTS . If not OK, use a
DRBIIItscan tool to perform further diagnosis. Refer
to the appropriate diagnostic information.
TESTS
(1) Verify the battery state of charge. (Refer to 8 -
ELECTRICAL/BATTERY SYSTEM/BATTERY -
DIAGNOSIS AND TESTING).
(2) Connect an ammeter (0 to 10 ampere scale
selected) in series with the clutch coil feed terminal.
Connect a voltmeter (0 to 20 volt scale selected) to
measure voltage across the battery and the clutch
coil.
(3) With the heater-A/C control in the A/C mode
and the blower at low speed, start the engine and
allow it to run at a normal idle speed.
(4) The compressor clutch should engage immedi-
ately, and the clutch coil voltage should be within
two volts of the battery voltage. If the coil voltage is
not within two volts of battery voltage, test the
clutch coil feed circuit for excessive voltage drop. If
the compressor clutch does not engage, use a
DRBIIItscan tool to perform further diagnosis. Refer
to the appropriate diagnostic information.
(5) With the ambient temperature at 21É C (70É F),
the compressor clutch coil is acceptable if the current
draw is 2.0 to 3.7 amperes at 11.5 to 12.5 volts at the
clutch coil. If the voltage is more than 12.5 volts, add
electrical loads by turning on electrical accessories
until the voltage reads below 12.5 volts.
(a) If the compressor clutch coil current reading
is zero, the coil is open and must be replaced.
(b) If the compressor clutch coil current reading
is four amperes or more, the coil is shorted and
must be replaced.
COMPRESSOR CLUTCH RELAY
DESCRIPTION
The compressor clutch relay (Fig. 17) is a Interna-
tional Standards Organization (ISO) micro-relay.
Relays conforming to the ISO specifications have
common physical dimensions, current capacities, ter-
minal patterns, and terminal functions. The ISO
micro-relay terminal functions are the same as a con-
ventional ISO relay. However, the ISO micro-relay
terminal pattern (or footprint) is different, the cur-
rent capacity is lower, and the physical dimensions
are smaller than those of the conventional ISO relay.
The compressor clutch relay is located in the Intelli-gent Power Module (IPM), which is in the engine
compartment near the battery. See the fuse and relay
layout map molded into the inner surface of the IPM
cover for compressor clutch relay identification and
location.
The black, molded plastic case is the most visible
component of the compressor clutch relay. Five male
spade-type terminals extend from the bottom of the
base to connect the relay to the vehicle electrical sys-
tem, and the ISO designation for each terminal is
molded into the base adjacent to each terminal.
OPERATION
The compressor clutch relay is an electromechani-
cal switch that uses a low current input from the
Powertrain Control Module (PCM) to control the high
current output to the compressor clutch electromag-
netic coil. The movable common feed contact point is
held against the fixed normally closed contact point
by spring pressure. When the relay coil is energized,
an electromagnetic field is produced by the coil wind-
ings. This electromagnetic field draws the movable
relay contact point away from the fixed normally
closed contact point, and holds it against the fixed
normally open contact point. When the relay coil is
de-energized, spring pressure returns the movable
contact point back against the fixed normally closed
contact point. The resistor or diode is connected in
parallel with the relay coil in the relay, and helps to
dissipate voltage spikes and electromagnetic interfer-
ence that can be generated as the electromagnetic
field of the relay coil collapses.
The compressor clutch relay terminals are con-
nected to the vehicle electrical system through a
receptacle in the Intelligent Power Module (IPM).
The inputs and outputs of the compressor clutch
relay include:
²The common feed terminal (30) receives a bat-
tery current input from a fuse in the IPM through a
fused B(+) circuit at all times.
²The coil ground terminal (85) receives a ground
input from the PCM through the compressor clutch
relay control circuit only when the PCM electroni-
cally pulls the control circuit to ground.
²The coil battery terminal (86) receives a battery
current input from the PCM through a fused ignition
switch output (run-start) circuit only when the igni-
tion switch is in the On or Start positions.
²The normally open terminal (87) provides a bat-
tery current output to the compressor clutch coil
through the compressor clutch relay output circuit
only when the compressor clutch relay coil is ener-
gized.
²The normally closed terminal (87A) is not con-
nected to any circuit in this application, but provides
RSCONTROLS - FRONT24-21
COMPRESSOR CLUTCH COIL (Continued)
ProCarManuals.com

a battery current output only when the compressor
clutch relay coil is de-energized.
Refer to the appropriate wiring information. The
wiring information includes wiring diagrams, proper
wire and connector repair procedures, further details
on wire harness routing and retention, as well as
pin-out and location views for the various wire har-
ness connectors, splices, and grounds.
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH RELAY
The compressor clutch relay (Fig. 17) is located in
the Intelligent Power Module (IPM), which is in the
engine compartment near the battery. See the fuse
and relay layout map molded into the inner surface
of the IPM cover for compressor clutch relay identifi-
cation and location. Remove the relay from the IPM
to perform the following tests:
(1) A relay in the de-energized position should
have continuity between terminals 87A and 30, and
no continuity between terminals 87 and 30. If OK, go
to Step 2. If not OK, replace the faulty relay.
(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 75   5 ohms. If OK, go to Step
3. If not OK, replace the faulty relay.
(3) Connect a battery to terminals 85 and 86.
There should now be continuity between terminals
30 and 87, and no continuity between terminals 87A
and 30. If OK, use a DRBIIItscan tool to perform
further diagnosis of the relay circuits. Refer to the
appropriate diagnostic information. If not OK,
replace the faulty relay.
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Unlatch and remove the cover from the Intelli-
gent Power Module (IPM).
(3) See the fuse and relay layout map molded into
the inner surface of the IPM cover for compressor
clutch relay identification and location.
(4) Remove the compressor clutch relay from the
IPM by pulling it straight up.
INSTALLATION
(1) See the fuse and relay layout map molded into
the inner surface of the Intelligent Power Module
(IPM) cover for compressor clutch relay identification
and location.
(2) Position the compressor clutch relay to the
proper receptacle in the IPM.
(3) Align the compressor clutch relay terminals
with the terminal cavities in the IPM relay recepta-
cle.
(4) Push down firmly on the compressor clutch
relay until the terminals are fully seated in the ter-
minal cavities in the IPM receptacle.
(5) Install and latch the cover onto the IPM.
(6) Reconnect the battery negative cable.
EVAPORATOR TEMPERATURE
SENSOR
DESCRIPTION
The evaporator temperature sensor is a switch that
is installed on the top of the expansion valve in the
right rear corner of the engine compartment (Fig.
18). The sensor has a small probe that is inserted in
a small well in the body of the expansion valve that
is filled with a special silicone-based thermal grease.
A small molded plastic push-in retainer secures the
sensor to a threaded hole in the top surface of the
expansion valve. Two terminals within a molded
plastic connector receptacle on the sensor connect it
to the vehicle electrical system through a take out
and connector of the HVAC wire harness.
Fig. 17 Compressor Clutch Relay
24 - 22 CONTROLS - FRONTRS
COMPRESSOR CLUTCH RELAY (Continued)
ProCarManuals.com