relay JEEP LIBERTY 2002 KJ / 1.G Workshop Manual

(5) Connect the test set hose or probe to the open
end of the leaking circuit. The test set gauge should
return to the 27 kPa (8 in. Hg.) setting shortly after
each connection is made. If OK, replace the faulty
disconnected component. If not OK, go to Step 6.
(6)
To locate a leak in a vacuum line, leave one end
of the line plugged and connect the test set hose or
probe to the other end of the line. Run your fingers
slowly along the line while watching the test set gauge.
The vacuum reading will fluctuate when your fingers
contact the source of the leak. To repair the vacuum
line, cut out the leaking section of the line. Then, insert
the loose ends of the line into a suitable length of 3 mil-
limeter (0.125 inch) inside diameter rubber hose.
STANDARD PROCEDURE - DIODE
REPLACEMENT
(1) Disconnect the battery negative cable and iso-
late it.
(2) Locate the diode in the harness, and remove
the protective covering.
(3) Remove the diode from the harness, pay atten-
tion to the current flow direction (Fig. 5).
(4) Remove the insulation from the wires in the
harness. Only remove enough insulation to solder in
the new diode.
(5) Install the new diode in the harness, making
sure current flow is correct. If necessary refer to the
appropriate wiring diagram for current flow.
(6) Solder the connection together using rosin core
type solder only.Do not use acid core solder.
(7) Tape the diode to the harness using electrical
tape making, sure the diode is completely sealed
from the elements.
(8) Re-connect the battery negative cable, and test
affected systems.
SPECIFICATIONS
A/C APPLICATION TABLE
Item Description Notes
Vehicle KJ- Liberty
System R134a w/ fixed
orifice tube
Compressor Sanden PXF-18 SP-10 PAG oil
Freeze±up
ControlA/C low
pressure switchaccumulator
mounted
Low psi Control opens < 25 psi
- resets > 43
psi
High psi Control switch - opens
> 450-490 psi -
resets <
270-330 psidischarge line
Control Head manual type
Mode Door vacuum
Blend Door electric
Recirculation
Doorvacuum
Blower Motor hardwired to
control headresistor block
Cooling Fan viscous for
cooling, single
speed electric
for A/C
Clutch Electro-
mechanical
Control relay PCM
Draw 2 - 3.7 amps @
12V  0.5V @ 70É F
Gap 0.0169- 0.0319
DRB IIIT
Reads TPS, RPM, A/C
switch test
Actuators clutch and fan
relay
Fig. 5 DIODE IDENTIFICATION
1 - CURRENT FLOW
2 - BAND AROUND DIODE INDICATES CURRENT FLOW
3 - DIODE AS SHOWN IN THE DIAGRAMS
KJHEATING & AIR CONDITIONING 24 - 9
HEATING & AIR CONDITIONING (Continued)

CONTROLS
TABLE OF CONTENTS
page page
A/C COMPRESSOR CLUTCH
DESCRIPTION - 3.7L and 2.4L.............12
OPERATION - 3.7L and 2.4L...............12
DIAGNOSIS AND TESTING - A/C
COMPRESSOR CLUTCH COIL...........12
STANDARD PROCEDURE - A/C
COMPRESSOR CLUTCH BREAK-IN.......12
REMOVAL.............................13
INSPECTION..........................14
INSTALLATION.........................14
A/C COMPRESSOR CLUTCH RELAY
DESCRIPTION.........................15
OPERATION...........................15
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH RELAY......................15
REMOVAL.............................16
INSTALLATION.........................16
A/C HEATER CONTROL
DESCRIPTION.........................16
REMOVAL.............................17
INSTALLATION.........................17
A/C HIGH PRESSURE SWITCH
DESCRIPTION.........................17
OPERATION...........................18
DIAGNOSIS AND TESTING - A/C HIGH
PRESSURE SWITCH...................18
REMOVAL.............................18
INSTALLATION.........................18
A/C LOW PRESSURE SWITCH
DESCRIPTION.........................18
OPERATION...........................18
DIAGNOSIS AND TESTING - A/C LOW
PRESSURE SWITCH...................19
REMOVAL.............................19
INSTALLATION.........................19
BLEND DOOR ACTUATOR
REMOVAL.............................20
INSTALLATION.........................20BLOWER MOTOR RELAY
DESCRIPTION.........................20
OPERATION...........................20
DIAGNOSIS AND TESTING - BLOWER
MOTOR RELAY.......................21
REMOVAL.............................21
INSTALLATION.........................22
BLOWER MOTOR RESISTOR
DESCRIPTION.........................22
OPERATION...........................22
DIAGNOSIS AND TESTING - BLOWER
MOTOR RESISTOR....................22
REMOVAL.............................22
INSTALLATION.........................22
BLOWER MOTOR SWITCH
DESCRIPTION.........................23
OPERATION...........................23
DIAGNOSIS AND TESTING - BLOWER
MOTOR SWITCH......................23
REMOVAL.............................23
INSTALLATION.........................23
MODE DOOR ACTUATOR
REMOVAL
REMOVAL - PANEL DOOR ACTUATOR.....24
REMOVAL - FLOOR - DEFROST DOOR
ACTUATOR..........................24
INSTALLATION
INSTALLATION - PANEL DOOR ACTUATOR . 25
INSTALLATION - FLOOR - DEFROST DOOR
ACTUATOR..........................25
RECIRCULATION DOOR ACTUATOR
REMOVAL.............................26
INSTALLATION.........................26
VACUUM CHECK VALVE
DESCRIPTION.........................28
OPERATION...........................28
REMOVAL.............................28
INSTALLATION.........................28
KJCONTROLS 24 - 11

A/C COMPRESSOR CLUTCH
DESCRIPTION - 3.7L and 2.4L
The compressor clutch assembly consists of a sta-
tionary electromagnetic coil, a rotor bearing and
rotor assembly, and a clutch plate (Fig. 1). The elec-
tromagnetic coil unit and the rotor bearing and rotor
assembly are each retained on the nose of the com-
pressor front housing with snap rings. The clutch
plate is keyed to the compressor shaft and secured
with a nut. These components provide the means to
engage and disengage the compressor from the
engine serpentine accessory drive belt.
OPERATION - 3.7L and 2.4L
When the clutch coil is energized, it magnetically
draws the clutch into contact with the rotor and
drives the compressor shaft. When the coil is not
energized, the rotor freewheels on the clutch rotor
bearing, which is part of the rotor. The compressor
clutch and coil are the only serviced parts on the
compressor.
The compressor clutch engagement is controlled by
several components: the A/C Heater mode control
switch, the A/C low pressure switch, the A/C high
pressure switch, the compressor clutch relay, and the
Powertrain Control Module (PCM). The PCM may
delay compressor clutch engagement for up to thirty
seconds. Refer to Electronic Control Modules for
more information on the PCM controls.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH COIL
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). The battery must
be fully-charged before performing the following
tests. Refer to Battery for more information.
(1) Connect an ammeter (0 to 10 ampere scale) in
series with the clutch coil terminal. Use a voltmeter
(0 to 20 volt scale) with clip-type leads for measuring
the voltage across the battery and the compressor
clutch coil.
(2) With the A/C Heater mode control switch in
any A/C mode, and the blower motor switch in the
lowest speed position, start the engine and run it at
normal idle.
(3) The compressor clutch coil voltage should read
within 0.2 volts of the battery voltage. If there is
voltage at the clutch coil, but the reading is not
within 0.2 volts of the battery voltage, test the clutch
coil feed circuit for excessive voltage drop and repair
as required. If there is no voltage reading at the
clutch coil, use a DRB IIItscan tool and (Refer to
Appropriate Diagnostic Information) for testing of the
compressor clutch circuit and PCM control. The fol-
lowing components must be checked and repaired as
required before you can complete testing of the clutch
coil:
²Fuses in the junction block and the Power Dis-
tribution Center (PDC)
²A/C heater mode control switch
²Compressor clutch relay
²A/C high pressure switch
²A/C low pressure switch
²Powertrain Control Module (PCM).
(4) The compressor clutch coil is acceptable if the
current draw measured at the clutch coil is 2.0 to 3.9
amperes with the electrical system voltage at 11.5 to
12.5 volts. This should only be checked with the work
area temperature at 21É C (70É F). If system voltage
is more than 12.5 volts, add electrical loads by turn-
ing on electrical accessories until the system voltage
drops below 12.5 volts.
(a) If the clutch coil current reading is four
amperes or more, the coil is shorted and should be
replaced.
(b) If the clutch coil current reading is zero, the
coil is open and should be replaced.
STANDARD PROCEDURE - A/C COMPRESSOR
CLUTCH BREAK-IN
After a new compressor clutch has been installed,
cycle the compressor clutch approximately twenty
times (five seconds on, then five seconds off). During
this procedure, set the A/C Heater control to the
Recirculation Mode, the blower motor switch in the
highest speed position, and the engine speed at 1500
Fig. 1 COMPRESSOR CLUTCH - TYPICAL
1 - CLUTCH PLATE
2 - NOT USED ON KJ
3 - ROTOR
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
24 - 12 CONTROLSKJ

CAUTION: If the snap ring is not fully seated in the
groove it will vibrate out, resulting in a clutch fail-
ure and severe damage to the front housing of the
compressor.
(6) Install the original clutch shims on the com-
pressor shaft.
(7) Install the clutch plate. Install the shaft hex
nut and tighten to 15±20 N´m (11±15 ft. lbs.).
(8) Check the clutch air gap with a feeler gauge
(Fig. 9). If the air gap does not meet the specification,
add or subtract shims as required. The air gap spec-
ification is 0.41 to 0.79 millimeter (0.016 to 0.031
inch).NOTE: The air gap is determined by the spacer
shims. When installing an original, or a new clutch
assembly, try the original shims first. When install-
ing a new clutch onto a compressor that previously
did not have a clutch, use a 1.0, 0.50, and 0.13 mil-
limeter (0.040, 0.020, and 0.005 inch) shims from the
new clutch hardware package that is provided with
the new clutch.
(9) To complete the procedure, (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION).
A/C COMPRESSOR CLUTCH
RELAY
DESCRIPTION
The compressor clutch relay is a International
Standards Organization (ISO) micro-relay. The termi-
nal designations and functions are the same as a con-
ventional ISO relay. However, the micro-relay
terminal orientation (footprint) is different, the cur-
rent capacity is lower, and the relay case dimensions
are smaller than those of the conventional ISO relay.
The compressor clutch relay is located in the Power
Distribution Center (PDC) in the engine compart-
ment. Refer to the PDC label for relay identification
and location.
OPERATION
The compressor clutch relay is a electromechanical
device that switches battery current to the compres-
sor clutch coil when the Powertrain Control Module
(PCM) grounds the coil side of the relay. The PCM
responds to inputs from the A/C Heater mode control
switch, the A/C low pressure switch, and the A/C
high pressure switch. (Refer to 24 - HEATING & AIR
CONDITIONING/CONTROLS/A/C COMPRESSOR
CLUTCH RELAY - DIAGNOSIS AND TESTING)
The compressor clutch relay cannot be repaired
and, if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - COMPRESSOR
CLUTCH RELAY
RELAY TEST
The compressor clutch relay (Fig. 10) is located in
the Power Distribution Center (PDC). Refer to the
PDC label for relay identification and location.
Remove the relay from the PDC to perform the fol-
lowing 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.
Fig. 8 CLUTCH PULLEY INSTALL
1 - ROTOR BEARING ASSEMBLY
2 - INSTALLER
Fig. 9 CHECK CLUTCH AIR GAP
1 - FEELER GAUGE
KJCONTROLS 24 - 15
A/C COMPRESSOR CLUTCH (Continued)

(2) Resistance between terminals 85 and 86 (elec-
tromagnet) should be 67.5 to 82.5 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, see Relay Circuit Test. If not OK,
replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
(1) The relay common feed terminal cavity (30) is
connected to fused battery feed. There should be bat-
tery voltage at the cavity for relay terminal 30 at all
times. If OK, go to Step 2. If not OK, repair the open
circuit to the fuse in the PDC as required.
(2) The relay normally closed terminal (87A) is not
used in this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the compressor clutch coil. There should
be continuity between this cavity and the A/C com-
pressor clutch relay output circuit cavity of the com-
pressor clutch coil wire harness connector. If OK, go
to Step 4. If not OK, repair the open circuit as
required.
(4) The relay coil battery terminal (86) is con-
nected to the fused ignition switch output (run/start)circuit. There should be battery voltage at the cavity
for relay terminal 86 with the ignition switch in the
On position. If OK, go to Step 5. If not OK, repair the
open circuit to the fuse in the junction block as
required.
(5) The coil ground terminal cavity (85) is switched
to ground through the Powertrain Control Module
(PCM). There should be continuity between this cav-
ity and the A/C compressor clutch relay control cir-
cuit cavity of the PCM wire harness connector C
(gray) at all times. If not OK, repair the open circuit
as required.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the cover from the Power Distribution
Center (PDC).
(3) Refer to the label on the PDC for compressor
clutch relay identification and location.
(4) Unplug the compressor clutch relay from the
PDC.
INSTALLATION
(1) Install the compressor clutch relay by aligning
the relay terminals with the cavities in the PDC and
pushing the relay firmly into place.
(2) Install the PDC cover.
(3) Connect the battery negative cable.
(4) Test the relay operation.
A/C HEATER CONTROL
DESCRIPTION
Both the heater-only and A/C heater systems use a
combination of mechanical, electrical, and vacuum
controls. These controls provide the vehicle operator
with a number of setting options to help control the
climate and comfort within the vehicle. Refer to the
owner's manual in the vehicle glove box for more
information on the features, use, and suggested oper-
ation of these controls.
The heater-only or A/C heater control panel is
located to the right of the instrument cluster on the
instrument panel. The control panel contains a rota-
ry-type temperature control knob, a rotary-type mode
control switch knob, and a rotary-type blower motor
speed switch knob. The control also has a push but-
ton to activate the rear window defogger.
The heater-only or A/C heater control panel cannot
be repaired. If faulty or damaged, the entire unit
must be replaced. The illumination lamps are avail-
able for service replacement.
Fig. 10 COMPRESSOR CLUTCH RELAY
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
24 - 16 CONTROLSKJ
A/C COMPRESSOR CLUTCH RELAY (Continued)

(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.
(4) Connect the battery negative cable.
BLEND DOOR ACTUATOR
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove A/C housing from vehicle(Refer to 24 -
HEATING & AIR CONDITIONING/DISTRIBUTION/
HVAC HOUSING - REMOVAL).
(3) Remove the screws that secure the blend door
actuator to the top of the HVAC housing. (Fig. 14).
(4) Remove the blend door actuator.
INSTALLATION
(1) Install the blend door actuator in place.
(2) Install and tighten the screws that secure the
blend door actuator to the housing. Tighten the
mounting screws to 2.4 ( .34) N´m (21 ( 3) in. lbs.).
(3) Install the HVAC housing into the vehicle(Re-
fer to 24 - HEATING & AIR CONDITIONING/DIS-
TRIBUTION/HVAC HOUSING - INSTALLATION).
(4) Install the blend door actuator electrical con-
nector from the wiring harness through the glove
box.
(5) Connect the battery negative cable.
BLOWER MOTOR RELAY
DESCRIPTION
The blower motor relay is a International Stan-
dards Organization (ISO)-type relay. The relay is a
electromechanical device that switches battery cur-
rent from a fuse in the Power Distribution Center
(PDC) directly to the blower motor. The relay is ener-
gized when the relay coil is provided a voltage signal
by the ignition switch. (Refer to 24 - HEATING &
AIR CONDITIONING/CONTROLS/BLOWER
MOTOR RELAY - DIAGNOSIS AND TESTING)
OPERATION
The blower motor relay is installed in a wire har-
ness connector that is secured to the passenger side
outboard end of the HVAC housing in the passenger
compartment, next to the HVAC wire harness con-
nector.
The blower motor relay cannot be repaired and, if
faulty or damaged, it must be replaced.
Fig. 14 HEATER CORE REMOVAL/INSTALLATION
1 - HEATER CORE
2- MOUNTING SCREW HOLE
3- INLET AND OUTLET TUBES
4- VACUUM HARNESS
5- ACTUATOR SCREWS (3)
6- ELECTRIC BLEND DOOR ACTUATOR
7- MOUNTING SCREW HOLE
8- HEATER CORE RETAINER TABS (4)
24 - 20 CONTROLSKJ
A/C LOW PRESSURE SWITCH (Continued)

DIAGNOSIS AND TESTING - BLOWER MOTOR
RELAY
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
RELAY TEST
The blower motor relay (Fig. 15) is located in the
PDC which is located under the hood.. Remove the
relay from the PDC 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 60.7 to 80.3 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, see the Relay Circuit Test. If not OK,
replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
(1) The relay common feed terminal cavity (30) is
connected to fused battery feed directly from a fuse
in the Power Distribution Center (PDC), and should
be hot at all times. Check for battery voltage at the
connector cavity for relay terminal 30. If OK, go to
Step 2. If not OK, repair the open circuit to the PDC
fuse as required.
(2) The relay normally closed terminal cavity (87A)
is not used for this application. Go to Step 3.
(3) The relay normally open terminal cavity (87) is
connected to the blower motor. When the relay is
energized, terminal 87 is connected to terminal 30
and provides full battery current to the blower motor
feed circuit. There should be continuity between the
connector cavity for terminal 87 and the blower
motor at all times. If OK, go to Step 4. If not OK,
repair the open circuit to the blower motor as
required.
(4) The coil battery terminal cavity (86) is con-
nected to the ignition switch. When the ignition
switch is placed in the On position, fused ignition
switch output is directed from a fuse in the junction
block to the relay electromagnetic coil to energize the
relay. There should be battery voltage at the connec-
tor cavity for relay terminal 86 with the ignition
switch in the On position. If OK, go to Step 5. If not
OK, repair the open circuit to the junction block fuse
as required.
(5) The coil ground terminal cavity (85) is con-
nected to ground. This terminal supplies the ground
for the relay electromagnet coil. There should be con-
tinuity between the connector cavity for relay termi-
nal 85 and a good ground at all times. If not OK,
repair the open circuit as required.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
Fig. 15 BLOWER MOTOR RELAY
30 - COMMON FEED
85 - COIL GROUND
86 - COIL BATTERY
87 - NORMALLY OPEN
87A - NORMALLY CLOSED
KJCONTROLS 24 - 21
BLOWER MOTOR RELAY (Continued)

(1) Disconnect and isolate the battery negative
cable.
(2) Unplug the blower motor relay from the PDC
located under the hood.
(3) Remove the blower motor relay.
INSTALLATION
(1) Install the blower motor relay by aligning the
relay terminals with the cavities in the PDC and
pushing the relay firmly into place.
(2) Connect the battery negative cable.
(3) Test the relay operation.
BLOWER MOTOR RESISTOR
DESCRIPTION
The blower motor resistor is mounted to the rear
side of the HVAC housing on the passenger side of
the vehicle.
OPERATION
The resistor is a credit card resistor that utilizes
resistor circuit tracers to reduce current flow to the
blower. The blower motor switch directs the ground
path through the correct resistor circuit to obtain the
selected speed.
The blower motor resistor cannot be repaired and,
if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RESISTOR
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.(2) Open the glove box door and reach in and
unplug the wire harness connector from the blower
motor resistor.
(3) Check for continuity between each of the
blower motor switch input terminals of the resistor
and the resistor output terminal. In each case there
should be continuity. If OK, repair the wire harness
circuits between the blower motor switch and the
blower motor resistor or blower motor relay as
required. If not OK, replace the faulty blower motor
resistor.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Open the glove box door to gain access to the
blower motor resistor.
(3) Pull out the lock on the blower motor resistor
wire harness connector to unlock the connector latch.
(4) Depress the latch on the blower motor resistor
wire harness connector and unplug the connector
from the resistor.
(5) Remove the two screws that secure the resistor
to the HVAC housing.
(6) Remove the resistor from the HVAC housing.
INSTALLATION
(1) Install the new resistor in the HVAC housing.
(2) Install the two screws that secure the resistor
to the HVAC housing and tighten to 2.2 N´m (20 in.
lbs.).
(3) Plug in the blower motor harness connector.
(4) Push in the lock on the blower motor resistor
harness connector.
(5) Close the glove box door.
(6) Connect the battery negative cable.
24 - 22 CONTROLSKJ
BLOWER MOTOR RELAY (Continued)

BLOWER MOTOR
DESCRIPTION
The blower motor and blower wheel are located in
the passenger side end of the HVAC housing, below
the glove box. The blower motor controls the velocity
of air flowing through the HVAC housing by spinning
a squirrel cage-type blower wheel within the housing
at the selected speed. The blower motor and wheel
can be removed from the housing inside the vehicle
without removing the dash or HVAC housing assem-
bly.
OPERATION
The blower motor will only operate when the igni-
tion switch is in the On position, and the A/C Heater
mode control switch knob is in any position, except
Off. The blower motor receives a fused battery feed
through the blower motor relay whenever the igni-
tion switch is in the On position. The blower motor
battery feed circuit is protected by a fuse in the
Power Distribution Center (PDC). Blower motor
speed is controlled by regulating the ground path
through the A/C Heater control blower motor switch
and the blower motor resistor.
The blower motor and blower motor wheel cannot
be repaired and, if faulty or damaged, they must be
replaced. The blower motor and blower wheel are ser-
viced only as a unit.
DIAGNOSIS AND TESTING - BLOWER MOTOR
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information). Possible causes of
an inoperative blower motor include:²Faulty fuse
²Faulty blower motor circuit wiring or wire har-
ness connectors
²Faulty blower motor resistor
²Faulty blower motor relay
²Faulty blower motor switch
²Faulty A/C Heater mode control switch
²Faulty blower motor.
Possible causes of the blower motor not operating
in all speeds include:
²Faulty blower motor switch
²Faulty blower motor resistor
²Faulty blower motor circuit wiring or wire har-
ness connectors.
VIBRATION
Possible causes of blower motor vibration include:
²Improper blower motor mounting
²Improper blower wheel mounting
²Blower wheel out of balance or bent
²Blower motor faulty.
NOISE
To verify that the blower is the source of the noise,
unplug the blower motor wire harness connector and
operate the HVAC system. If the noise goes away,
possible causes include:
²Foreign material in the HVAC housing
²Improper blower motor mounting
²Improper blower wheel mounting
²Blower motor faulty.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN AN ACCIDENTAL
AIRBAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
24 - 30 DISTRIBUTIONKJ

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. Connect
the 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.
DESCRIPTION - CIRCUIT ACTUATION TEST
MODE
The Circuit Actuation Test Mode checks for proper
operation of output circuits or devices the Powertrain
Control Module (PCM) may not internally recognize.
The PCM attempts to activate these outputs and
allow an observer to verify proper operation. Most of
the tests provide an audible or visual indication of
device operation (click of relay contacts, fuel spray,
etc.). Except for intermittent conditions, if a device
functions properly during testing, assume the device,
its associated wiring, and driver circuit work cor-
rectly. Connect the DRB scan tool to the data link
connector and access the Actuators screen.
DESCRIPTION - DIAGNOSTIC TROUBLE CODES
A Diagnostic Trouble Code (DTC) indicates the
PCM has recognized an abnormal condition in the
system.Remember that DTC's are the results of a sys-
tem or circuit failure, but do not directly iden-
tify the failed component or components.
NOTE: For a list of DTC's, refer to the charts in this
section.
BULB CHECK
Each time the ignition key is turned to the ON
position, the malfunction indicator (check engine)
lamp on the instrument panel should illuminate for
approximately 2 seconds then go out. This is done for
a bulb check.
OBTAINING DTC'S USING DRB SCAN TOOL
(1) Connect the DRB scan tool to the data link
(diagnostic) connector. This connector is located in
the passenger compartment; at the lower edge of
instrument panel; near the steering column.
(2) Turn the ignition switch on and access the
ªRead Faultº screen.
(3) Record all the DTC's and ªfreeze frameº infor-
mation shown on the DRB scan tool.
(4) To erase DTC's, use the ªErase Trouble Codeº
data screen on the DRB scan tool.Do not erase any
DTC's until problems have been investigated
and repairs have been performed.
(M)Malfunction Indicator Lamp (MIL) illuminated during engine operation if this DTC was recorded
(depending if required by CARB and/or EPA). MIL is displayed as an engine icon on instrument panel.
(G)Generator lamp illuminated
Generic Scan
Tool P-CodeDRB Scan Tool Display Brief Description of DTC
P0030 (M) 1/1 O2 Sensor Heater Circuit
MalfunctionProblem detected in oxygen sensor heater relay circuit.
P0031 (M) 1/1 O2 Sensor Heater Circuit Low Problem detected in oxygen sensor heater relay circuit.
P0032 (M) 1/1 O2 Sensor Heater Circuit High Problem detected in oxygen sensor heater relay circuit.
P0036 (M) 1/2 O2 Sensor Heater Circuit
MalfunctionProblem detected in oxygen sensor heater relay circuit.
P0037 (M) 1/2 O2 Sensor Heater Circuit Low Problem detected in oxygen sensor heater relay circuit.
P0038 (M) 1/2 O2 Sensor Heater Circuit High Problem detected in oxygen sensor heater relay circuit.
P0043 (M) 1/3 O2 Sensor Heater Circuit Low Problem detected in oxygen sensor heater relay circuit.
P0044 (M) 1/3 O2 Sensor Heater Circuit High Problem detected in oxygen sensor heater relay circuit.
P0051 (M) 2/1 O2 Sensor Heater Circuit Low Problem detected in oxygen sensor heater relay circuit.
P0052 (M) 2/1 O2 Sensor Heater Circuit High Problem detected in oxygen sensor heater relay circuit.
25 - 2 EMISSIONS CONTROLKJ
EMISSIONS CONTROL (Continued)