relay DODGE RAM 2002 Service Repair Manual

CONTROLS
TABLE OF CONTENTS
page page
CONTROLS
DIAGNOSIS AND TESTING.................10
DIAGNOSIS AND TESTING - VACUUM
SYSTEM.............................10
A/C COMPRESSOR CLUTCH
DESCRIPTION..........................11
OPERATION............................13
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
COMPRESSOR CLUTCH COIL............13
STANDARD PROCEDURE
STANDARD PROCEDURE - A/C
COMPRESSOR CLUTCH BREAK-IN........13
REMOVAL..............................13
INSPECTION............................15
INSTALLATION..........................15
A/C COMPRESSOR CLUTCH RELAY
DESCRIPTION..........................17
OPERATION............................17
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C
COMPRESSOR CLUTCH RELAY...........17
REMOVAL..............................18
INSTALLATION..........................18
A/C-HEATER CONTROL
DESCRIPTION..........................18
OPERATION............................18
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C HEATER
CONTROL............................18
REMOVAL..............................19
INSTALLATION..........................19
A/C HIGH PRESSURE SWITCH
DESCRIPTION..........................20
OPERATION............................20
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C HIGH
PRESSURE SWITCH....................20
REMOVAL..............................20
INSTALLATION..........................20
A/C LOW PRESSURE SWITCH
DESCRIPTION..........................21
OPERATION............................21DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - A/C LOW
PRESSURE SWITCH....................21
REMOVAL..............................21
INSTALLATION..........................21
BLOWER MOTOR RELAY
DESCRIPTION..........................22
OPERATION............................22
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - BLOWER
MOTOR RELAY........................22
REMOVAL..............................23
INSTALLATION..........................23
BLOWER MOTOR RESISTOR BLOCK
DESCRIPTION..........................23
OPERATION............................23
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - BLOWER
MOTOR RESISTOR BLOCK...............23
REMOVAL..............................24
INSTALLATION..........................24
BLOWER MOTOR SWITCH
DESCRIPTION..........................24
OPERATION............................24
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - BLOWER
MOTOR SWITCH.......................25
REMOVAL..............................25
BLEND DOOR ACTUATOR
REMOVAL..............................25
INSTALLATION..........................25
MODE DOOR ACTUATOR
REMOVAL..............................26
INSTALLATION..........................27
RECIRCULATION DOOR ACTUATOR
REMOVAL..............................27
INSTALLATION..........................28
VACUUM CHECK VALVE
DESCRIPTION..........................28
OPERATION............................28
REMOVAL..............................29
INSTALLATION..........................29
BR/BECONTROLS 24 - 9

OPERATION
The compressor clutch assembly provides the
means to engage and disengage the compressor from
the engine serpentine accessory drive belt. When the
clutch coil is energized, it magnetically draws the
clutch into contact with the pulley and drives the
compressor shaft. When the coil is not energized, the
pulley freewheels on the clutch hub bearing, which is
part of the pulley. 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 loss of charge switch, the a/c pressure
transducer, the compressor clutch relay, the evapora-
tor temperature sensor and the Powertrain Control
Module (PCM). The PCM may delay compressor
clutch engagement for up to thirty seconds(Refer to 8
- ELECTRICAL/ELECTRONIC CONTROL MOD-
ULES/POWERTRAIN CONTROL MODULE -
DESCRIPTION).
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. The following 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
to 2000 rpm. This procedure (burnishing) will seat
the opposing friction surfaces and provide a higher
compressor clutch torque capability.
REMOVAL
The refrigerant system can remain fully-charged
during compressor clutch, pulley, or coil replacement.
The compressor clutch can be serviced in the vehicle.
(1) Disconnect and isolate the battery negative
cable.
(2) On models with the diesel engine option,
remove the compressor from the engine. Do not
Fig. 4 COMPRESSOR CLUTCH - TYPICAL
1 - CLUTCH PLATE
2 - SHAFT KEY
3 - PULLEY
4 - COIL
5 - CLUTCH SHIMS
6 - SNAP RING
7 - SNAP RING
BR/BECONTROLS 24 - 13
A/C COMPRESSOR CLUTCH (Continued)

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 1.0, 0.50, and 0.13 milli-
meter (0.040, 0.020, and 0.005 inch) shims from the
clutch hardware package that is provided with the
new clutch.
(12) On models with the diesel engine option,
install the compressor on the engine. (Refer to 24 -
HEATING & AIR CONDITIONING/PLUMBING/A/C
COMPRESSOR - INSTALLATION)
(13) Connect the battery negative cable.
A/C COMPRESSOR CLUTCH
RELAY
DESCRIPTION
The a/c 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.
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 control, the a/closs of charge switch, the a/c pressure transducer and
the evaporator fin probe.
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.
The compressor clutch relay cannot be repaired
and, if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - A/C COMPRESSOR
CLUTCH RELAY
RELAY TEST
The compressor clutch relay (Fig. 16) 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.
(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, see the Relay Circuit Test below. If not
OK, replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
Fig. 15 CHECK CLUTCH AIR GAP
1 - FEELER GAUGE
Fig. 16 COMPRESSOR CLUTCH RELAY
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
BR/BECONTROLS 24 - 17
A/C COMPRESSOR CLUTCH (Continued)

(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) (Fig. 17).
(3) Refer to the label on the PDC for compressor
clutch relay identification and location.(4) Unplug the compressor clutch relay from the
PDC and remove it.
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 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 man-
ual in the vehicle glove box for more information on
the features, use, and suggested operation of these
controls.
OPERATION
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. On models with the optional
heated mirror system, a momentary push button
switch and indicator lamp are located near the bot-
tom of the a/c heater control panel. Refer to Heated
Mirrors for more information on this feature.
The heater-only or a/c heater control panel cannot
be repaired. If faulty or damaged, the entire unit
must be replaced. The control knobs and the illumi-
nation lamps are available for service replacement.
DIAGNOSIS AND TESTING - A/C HEATER
CONTROL
Satisfactory heater and air conditioner perfor-
mance depends upon proper operation and adjust-
ment of all operating controls and refrigeration
system components. For circuit descriptions and dia-
grams, (Refer to Appropriate Wiring Information).
These inspections, tests, and adjustments should be
used to locate the cause of a malfunction.
Operation must be tested as described in the fol-
lowing sequence:
(1) Inspect and adjust the serpentine drive bel-
t(Refer to 7 - COOLING/ACCESSORY DRIVE/DRIVE
BELTS - DIAGNOSIS AND TESTING).
(2) Start the engine and hold the idle speed at
1,300 rpm.
Fig. 17 POWER DISTRIBUTION CENTER
1 - COVER
2 - POWER DISTRIBUTION CENTER
24 - 18 CONTROLSBR/BE
A/C COMPRESSOR CLUTCH RELAY (Continued)

(4) Connect the battery negative cable.
BLOWER MOTOR RELAY
DESCRIPTION
The blower motor relay is an International Stan-
dards Organization (ISO)-type relay. The relay is an
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. This arrangement reduces the
amount of battery current that must flow through
the ignition switch.
OPERATION
The blower motor relay control circuit is protected
by a fuse located in the junction block. When the
relay is de-energized, the blower motor receives no
battery current.The blower motor relay is located in the PDC in
the engine compartment. Refer to the PDC label for
blower motor relay identification and location.
The blower motor relay cannot be repaired and, if
faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RELAY
RELAY TEST
The blower motor relay (Fig. 21) is located in the
Power Distribution Center (PDC). Remove the blower
motor 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 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, see Relay Circuit Test below. If not
OK, replace the faulty relay.
RELAY CIRCUIT TEST
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
Fig. 20 ACCUMULATOR AND A/C LOW PRESSURE
SWITCH
1 - CLIP
2 - BRACKET
3 - SCREW
4 - BAND
5 - ACCUMULATOR
6 - TO SUCTION LINE
7 - A/C LOW PRESSURE SWITCH
8 - FROM EVAPORATOR OUTLET
Fig. 21 BLOWER MOTOR RELAY
TERMINAL LEGEND
NUMBER IDENTIFICATION
30 COMMON FEED
85 COIL GROUND
86 COIL BATTERY
87 NORMALLY OPEN
87A NORMALLY CLOSED
24 - 22 CONTROLSBR/BE
A/C LOW PRESSURE SWITCH (Continued)

(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
PDC 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
PDC cavity for terminal 87 and the blower motor
relay output circuit cavity of the blower motor wire
harness connector 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 PDC
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 electromagnetic coil. There should be
continuity between the PDC cavity for relay terminal
85 and a good ground 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) (Fig. 22).
(3) Refer to the label on the PDC for blower motor
relay identification and location.
(4) Unplug the blower motor relay from the PDC
and remove it.
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) Install the PDC cover.
(3) Connect the battery negative cable.
(4) Test the relay operation.
BLOWER MOTOR RESISTOR
BLOCK
DESCRIPTION
The blower motor resistor is mounted to the bot-
tom of the HVAC housing, under the instrument
panel and just inboard of the blower motor. It can be
accessed without removing any other components.
OPERATION
The resistor has multiple resistor wires, each of
which will change the resistance in the blower motor
ground path to change the blower motor speed. The
blower motor switch directs the ground path through
the correct resistor wire to obtain the selected blower
motor speed.
With the blower motor switch in the lowest speed
position, the ground path for the motor is applied
through all of the resistor wires. Each higher speed
selected with the blower motor switch applies the
blower motor ground path through fewer of the resis-
tor wires, increasing the blower motor speed. When
the blower motor switch is in the highest speed posi-
tion, the blower motor resistor is bypassed and the
blower motor receives a direct path to ground.
The blower motor resistor cannot be repaired and,
if faulty or damaged, it must be replaced.
DIAGNOSIS AND TESTING - BLOWER MOTOR
RESISTOR BLOCK
For circuit descriptions and diagrams, (Refer to
Appropriate Wiring Information).
Fig. 22 POWER DISTRIBUTION CENTER
1 - COVER
2 - POWER DISTRIBUTION CENTER
BR/BECONTROLS 24 - 23
BLOWER MOTOR RELAY (Continued)

AIR OUTLETS
REMOVAL - DEMISTER GRILLES
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry at the perimeter edges of
the demister grille to release the snap features from
the instrument panel top cover.
(2) Remove the demister grille from the instru-
ment panel.
REMOVAL - PANEL OUTLET BARRELS
WARNING: THE PANEL OUTLET BARRELS
INSTALLED IN THE PASSENGER SIDE AIRBAG
DOOR PANEL OUTLET HOUSINGS MUST NEVER
BE REINSTALLED FOLLOWING REMOVAL FOR ANY
REASON. THEY MUST BE REPLACED WITH NEW
BARRELS. FAILURE TO OBSERVE THIS WARNING
COULD RESULT IN OCCUPANT INJURIES UPON
AIRBAG DEPLOYMENT.
(1) Using a trim stick or another suitable wide
flat-bladed tool, gently pry near the center of either
side of the panel outlet barrel to release the snap-fit
pivots on the barrel from the pivot pins in the outlet
housing of the passenger side airbag module or the
instrument cluster bezel (Fig. 2).
(2) Remove the barrel from the panel outlet hous-
ing.
INSTALLATION - DEMISTER GRILLES
(1) To install the demister grille, position the grille
in the opening of the instrument panel top cover and
press inwards firmly and evenly near the center of
both sides of the grille until it snaps into place.
INSTALLATION - PANEL OUTLET BARRELS
WARNING: THE PANEL OUTLET BARRELS
INSTALLED IN THE PASSENGER SIDE AIRBAG
DOOR PANEL OUTLET HOUSINGS MUST NEVER
BE REINSTALLED FOLLOWING REMOVAL FOR ANY
REASON. THEY MUST BE REPLACED WITH NEW
BARRELS. FAILURE TO OBSERVE THIS WARNING
COULD RESULT IN OCCUPANT INJURIES UPON
AIRBAG DEPLOYMENT.
(1) To install a new panel outlet barrel, position
the barrel in the outlet housing and press inwards
firmly and evenly near the center of both sides of the
panel outlet barrel until the pivots snap into place.
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 the air flowing through the HVAC housing by spin-
ning a squirrel cage-type blower wheel within the
housing at the selected speed. The blower motor and
blower wheel can be serviced from the passenger
compartment side of the housing.
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).
The blower motor relay control circuit is protected by
a fuse in the junction block. Blower motor speed is
controlled by regulating the ground path through the
a/c heater mode control switch, the blower motor
switch, and the blower motor resistor.
The blower motor and blower wheel cannot be
repaired and, if faulty or damaged, they must be
replaced. The blower motor and blower wheel may be
serviced separately, although if the motor is to be
replaced, a blower wheel will come as part of a pre-
balanced assembly.
Fig. 2 PANEL OUTLET BARRELS
1 - DEFROSTER OUTLETS
2 - DEMISTER OUTLET GRILLE
3 - PANEL OUTLET BARRELS
4 - DEMISTER OUTLET GRILLE
BR/BEDISTRIBUTION 24 - 31

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 fuse
²Faulty blower motor switch
²Faulty blower motor resistor
²Faulty blower motor relay
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 deformed
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
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the blower motor cooling tube from
the nipple on the blower motor housing (Fig. 3).
(3) Disengage the blower motor wire harness from
the wire harness retainer.
(4) Unplug the blower motor wire harness connec-
tor from the HVAC housing wire harness.
(5) Remove the three screws that secure the
blower motor and blower wheel assembly to the
HVAC housing.
(6) Lower the blower motor and wheel assembly,
and cover, from the HVAC housing.
(7) Remove the blower wheel retainer clip and
remove the wheel from the blower motor shaft (Fig.
4).
INSTALLATION
(1) If installing the blower motor wheel only, press
the blower wheel hub onto the blower motor shaft.
Be sure the flat on the blower motor shaft is indexed
to the flat on the inside of the blower wheel hub.
(2) Install the retainer clip over the blower wheel
hub. The ears of the retainer clip must be indexed
over the flats on the blower motor shaft and blower
wheel hub.
Fig. 3 BLOWER MOTOR REMOVE/INSTALL
1 - BLOWER MOTOR HOUSING
2 - COOLING TUBE
3 - ELECTRICAL CONNECTOR
24 - 32 DISTRIBUTIONBR/BE
BLOWER MOTOR (Continued)

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.
Fig. 2 Engine Control Module (ECM) Location
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - FUEL TRANSFER PUMP
4 - MOUNTING BOLTS (3)
5 - 50±WAY CONNECTOR
25 - 2 EMISSIONS CONTROLBR/BE
EMISSIONS CONTROL (Continued)

(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.
P0057 (M) 2/2 O2 Sensor Heater Circuit Low Problem detected in oxygen sensor heater relay circuit.
P0058 (M) 2/2 O2 Sensor Heater Circuit High Problem detected in oxygen sensor heater relay circuit.
P0071 (M) Amb/Bat Temp Sensor Performance
P0106 Barometric Pressure Out of Range MAP sensor input voltage out of an acceptable range
detected during reading of barometric pressure at key-on.
P0107 (M) Map Sensor Voltage Too Low MAP sensor input below minimum acceptable voltage.
P0108 (M) Map Sensor Voltage Too High MAP sensor input above maximum acceptable voltage.
PO111 (M) Intake Air Temp Sensor Performance
P0112 (M) Intake Air Temp Sensor Voltage Low Intake air (charge) temperature sensor input below the
minimum acceptable voltage.
P0113 (M) Intake Air Temp Sensor Voltage High Intake air (charge) temperature sensor input above the
maximum acceptable voltage.
P0116 Coolant Temp Sensor Performance A rationatilty error has been detected in the coolant temp
sensor.
P0117 (M) ECT Sensor Voltage Too Low Engine coolant temperature sensor input below the minimum
acceptable voltage.
P0118 (M) ECT Sensor Voltage Too High Engine coolant temperature sensor input above the
maximum acceptable voltage.
P0121 (M) TPS Voltage Does Not Agree With
MAPTPS signal does not correlate to MAP sensor signal.
P0121 (M) Accelerator Position Sensor (APPS)
Signal Voltage Too LowAPPS voltage input below the minimum acceptable voltage.
P0122 (M) Throttle Position Sensor Voltage Low Throttle position sensor input below the acceptable voltage
range.
P0122 (M) Accelerator Position Sensor (APPS)
Signal Voltage Too LowAPPS voltage input below the minimum acceptable voltage.
P0123 (M) Throttle Position Sensor Voltage High Throttle position sensor input above the maximum
acceptable voltage.
P0123 (M) Accelerator Position Sensor (APPS)
Signal Voltage Too HighAPPS voltage input above the maximum acceptable voltage.
BR/BEEMISSIONS CONTROL 25 - 3
EMISSIONS CONTROL (Continued)