SPECIAL TOOLS
BATTERY TEMPERATURE
SENSOR
DESCRIPTION
(NGC Vehicles) The PCM incorporates a Battery
Temperature Sensor (BTS) on its circuit board.
OPERATION
The PCM uses the temperature of the battery area
to control the charge system voltage. This tempera-
ture, along with data from monitored line voltage, is
used by the PCM to vary the battery charging rate.
The system voltage is higher at cold temperatures
and is gradually reduced as temperature around the
battery increases.
For vehicles with 1.6L engine, there is no physical
battery temp sensor in place to detect battery temp.
Rather, an algorithm buit in PCM is employed to pre-
dict battery temp using inlet air temp, vehicle speed,
and coolant temp, among other signals. The PCM
maintains the optimal output of the generator by
monitoring battery voltage and controlling it to a
range of 13.5 - 14.7 volts based on battery tempera-
ture. The system target voltage is 13.5 ± 14.7 volts.
However the actual voltage go below this during
heavy electrical loads and generator speeds. Also the
actual voltage can be lower than the target voltage
between the battery and the battery voltage sense
circuit, approximately 0.2 Ð 0.3 volts.
The battery temperature sensor is also used for
OBD II diagnostics. Certain faults and OBD II mon-
itors are either enabled or disabled depending upon
the battery temperature sensor input (example: dis-
able purge and EGR, enable LDP). Most OBD II
monitors are disabled below 20ÉF.
REMOVAL
The battery temperature sensor is not serviced sep-
arately. If replacement is necessary, the PCM must
be replaced.
GENERATOR
DESCRIPTION
The generator is belt-driven by the engine. The
generator produces DC voltage at the B+ terminal. If
the generator is failed, the generator assembly sub-
components (generator and decoupler pulley) must be
inspected for individual failure and replaced accord-
ingly.
OPERATION
As the energized rotor begins to rotate within the
generator, the spinning magnetic field induces a cur-
rent into the windings of the stator coil. Once the
generator begins producing sufficient current, it also
provides the current needed to energize the rotor.
The Y type stator winding connections deliver the
induced AC current to 3 positive and 3 negative
diodes for rectification. From the diodes, rectified DC
current is delivered to the vehicles electrical system
through the generator, battery, and ground terminals.
Excessive or abnormal noise emitting from the gen-
erator may be caused by:
²Worn, loose or defective bearings
²Loose or defective drive pulley (2.4L) or decou-
pler (3.3/3.8L)
²Incorrect, worn, damaged or misadjusted drive
belt
²Loose mounting bolts
²Misaligned drive pulley
²Defective stator or diode
²Damaged internal fins
REMOVAL
REMOVAL - 2.4L
(1) Release hood latch and open hood.
(2) Disconnect battery negative cable.
(3) Disconnect the Inlet Air Temperature sensor.
(4) Remove the Air Box, refer to the Engine/Air
Cleaner for more information.
(5) Remove the EVAP Purge solenoid from its
bracket and reposition.
(6) Disconnect the push-in field wire connector
from back of generator.
(7) Remove nut holding B+ wire terminal to back
of generator.
(8) Separate B+ terminal from generator.
GENERATOR DECOUPLER 8433
8F - 24 CHARGINGRS
CHARGING (Continued)
(8) Raise vehicle and support.
(9) Install the lower mounting bolt and tighten.
(10) Install the lower oil dip stick tube bolt and
tighten (Fig. 9).
(11) Install accessory drive belt, refer to the Cool-
ing System section for proper procedures.
(12) Install the right front lower splash shield.
(13) Lower vehicle.
(14) Install wiring harness to the oil dip stick tube
(15) Connect battery negative cable.
(16) Verify generator output rate.
GENERATOR DECOUPLER
PULLEY
DESCRIPTION
The Generator Decoupler is a one way clutch (Fig.
11). It is attached to the generator and replaces the
standard pulley. It is a non-serviceable item and is to
be replaced as an assembly. It is a dry operation (no
grease or lubricants). The operation of it is not tem-
perature sensitive and has a low sensitivity to elec-
trical load.
OPERATION
The generator decoupler is a one way clutch and
should be replaced as an assembly. It is designed to
help reduce belt tension fluctuation, reduce fatigue
loads, improve belt life, reduce hubloads on compo-
nents, and reduce noise.
DIAGNOSIS AND TESTING - GENERATOR DECOUPLER PULLEY
CONDITION VERIFICATION PROCEDURE POSSIBLE
CAUSESCORRECTION
Does not drive generator
(Generator not Charging)1. Start engine and allow engine to idle. Clutch
failureReplace
Decoupler
2.Verify generator pulley is rotating.
3. View generator internal fins thru generator housing.
4. Fins either do not rotate or rotate very erratic.
5. Rotate decoupler pulley in clockwise direction then
quickly rotate in counterclockwise direction to see if
clutch engages.
Noise from generator at
engine shut down.1. Start engine and allow engine to idle. Defective
decoupler
pulley
bearing.Replace
decoupler
pulley.
2. Shutdown engine and listen to generator.
3. Noise heard just as engine stops. Sounds like a
click.
4. Remove accessory drive belt.
5. Verify rotation in counterclock wise direction is
rough.
Fig. 11 GENERATOR DECOUPLER 3.3/3.8L
8F - 28 CHARGINGRS
GENERATOR (Continued)
(7) Install the right front lower splash shield.
(8) Lower vehicle.
(9) Connect battery negative cable.
VOLTAGE REGULATOR
DESCRIPTION
The Electronic Voltage Regulator (EVR) is not a
separate component. It is actually a voltage regulat-ing circuit located within the Powertrain Control
Module (PCM). The EVR is not serviced separately. If
replacement is necessary, the PCM must be replaced.
OPERATION
The amount of DC current produced by the gener-
ator is controlled by EVR circuitry contained within
the PCM. This circuitry is connected in series with
the generators second rotor field terminal and its
ground.
Voltage is regulated within the PCM on the NGC
vehicles, to control the strength of the rotor magnetic
field. The EVR circuitry monitors system line voltage
at the PDC and calculated battery temperature or
inlet air temperature sensor (refer to Inlet Air Tem-
perature Sensor, if equipped, for more information ).
It then determines a target charging voltage. If
sensed battery voltage is lower than the target volt-
age, the PCM feeds the field winding until sensed
battery voltage is at the target voltage. A circuit in
the PCM cycles the feed side of the generator field at
250 times per second (250Hz), but has the capability
to feed the field control wire 100% of the time (full
field) to achieve the target voltage. If the charging
rate cannot be monitored (limp-in), a duty cycle of
20% is used by the PCM in order to have some gen-
erator output. Also refer to Charging System Opera-
tion for additional information.
Fig. 15 DECOUPLER INSTALLATION (Litens)
8F - 30 CHARGINGRS
GENERATOR DECOUPLER PULLEY (Continued)
STARTING
TABLE OF CONTENTS
page page
STARTING
DESCRIPTION.........................31
OPERATION...........................31
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - STARTING
SYSTEM TEST.......................31
DIAGNOSIS AND TESTING - CONTROL
CIRCUIT TEST........................33
DIAGNOSIS AND TESTING - FEED CIRCUIT
RESISTANCE TEST....................35
DIAGNOSIS AND TESTING - FEED CIRCUIT
TEST...............................36SPECIFICATIONS
Torques.............................36
STARTER ...........................37
STARTER MOTOR
REMOVAL
REMOVAL - 2.4L......................37
REMOVAL - 3.3/3.8L...................38
REMOVAL - 2.5L......................38
INSTALLATION
INSTALLATION - 2.4L..................39
INSTALLATION - 3.3/3.8L................39
INSTALLATION - 2.5L..................39
STARTING
DESCRIPTION
The starting system consists of:
²Starter relay
²Starter motor (including an integral starter sole-
noid)
Other components to be considered as part of start-
ing system are:
²Battery
²Battery cables
²Ignition switch and key lock cylinder
²Clutch pedal position switch (manual transmis-
sion)
²Park/neutral position switch (automatic trans-
mission)
²Wire harnesses and connections.
The Battery, Starting, and Charging systems oper-
ate in conjunction with one another, and must be
tested as a complete system. For correct operation of
starting/charging systems, all components used in
these 3 systems must perform within specifications.
When attempting to diagnose any of these systems, it
is important that you keep their interdependency in
mind.
The diagnostic procedures used in each of these
groups include the most basic conventional diagnostic
methods, to the more sophisticated On-Board Diag-
nostics (OBD) built into the Powertrain Control Mod-
ule (PCM). Use of an induction-type milliampere
ammeter, volt/ohmmeter, battery charger, carbon pile
rheostat (load tester), and 12-volt test lamp may be
required.
OPERATION
These components form two separate circuits. A
high amperage circuit that feeds the starter motor up
to 300+ amps, and a control circuit that operates on
less than 20 amps.
The PCM controls a double start over-ride safety
that does not allow the starter to be engaged if the
engine is already running.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - STARTING
SYSTEM TEST
For circuit descriptions and diagrams, refer to the
Wiring Diagrams.
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE PASSIVE RESTRAINT SYS-
TEMS BEFORE ATTEMPTING STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
INSPECTION
Before removing any unit from the starting system
for repair or diagnosis, perform the following inspec-
tions:
²Battery- Visually inspect the battery for indi-
cations of physical damage and loose or corroded
cable connections. Determine the state-of-charge and
cranking capacity of the battery. Charge or replace
RSSTARTING8F-31
CONDITION POSSIBLE CAUSE CORRECTION
2. STARTING CIRCUIT
WIRING FAULTY.2. REFER TO THE FEED CIRCUIT RESISTANCE TEST AND
THE FEED CIRCUIT TEST IN THIS SECTION. REPAIR AS
NECESSARY.
3. STARTER ASSEMBLY
FAULTY.3. IF ALL OTHER STARTING SYSTEM COMPONENTS AND
CIRCUITS CHECK OK, REPLACE STARTER ASSEMBLY.
4. ENGINE SEIZED. 4. REFER TO THE ENGINE SECTION, FOR DIAGNOSTIC AND
SERVICE PROCEDURES.
5. LOOSE
CONNECTION AT
BATTERY, PDC,
STARTER, OR ENGINE
GROUND.5. INSPECT FOR LOOSE CONNECTIONS.
6. FAULTY TEETH ON
RING GEAR.6. ROTATE FLYWHEEL 360É, AND INSPECT TEETH AND RING
GEAR REPLACED IF DAMAGED.
STARTER
ENGAGES,
SPINS OUT
BEFORE
ENGINE
STARTS.1. BROKEN TEETH ON
STARTER RING GEAR.1. REMOVE STARTER. INSPECT RING GEAR AND REPLACE
IF NECESSARY.
2. STARTER ASSEMBLY
FAULTY.2. IF ALL OTHER STARTING SYSTEM COMPONENTS AND
CIRCUITS CHECK OK, REPLACE STARTER ASSEMBLY.
STARTER DOES
NOT
DISENGAGE.1. STARTER
IMPROPERLY
INSTALLED.1. INSTALL STARTER. TIGHTEN STARTER MOUNTING
HARDWARE TO CORRECT TORQUE SPECIFICATIONS.
2. STARTER RELAY
FAULTY.2. REFER TO RELAY TEST, IN THIS SECTION. REPLACE
RELAY, IF NECESSARY.
3. IGNITION SWITCH
FAULTY.3. REFER TO IGNITION SWITCH TEST, IN THE STEERING
SECTION. REPLACE SWITCH, IF NECESSARY.
4. STARTER ASSEMBLY
FAULTY.4. IF ALL OTHER STARTING SYSTEM COMPONENTS AND
CIRCUITS CHECK OK, REPLACE STARTER ASSEMBLY.
5. FAULTY TEETH ON
RING GEAR.5. ROTATE FLYWHEEL 360É, AND INSPECT TEETH AND RING
GEAR REPLACED IF DAMAGED.
DIAGNOSIS AND TESTING - CONTROL
CIRCUIT TEST
The starter control circuit has:
²Starter motor with integral solenoid
²Starter relay
²Transmission range sensor, or Park/Neutral
Position switch with automatic transmissions
²Ignition switch
²Battery
²All related wiring and connections
²Powertrain Control Module (PCM)
CAUTION: Before performing any starter tests, the
ignition and fuel systems must be disabled.²To disable ignition and fuel systems, disconnect
the Automatic Shutdown Relay (ASD). The ASD relay
is located in the Power Distribution Center (PDC).
Refer to the PDC cover for the proper relay location.
STARTER SOLENOID
WARNING: CHECK TO ENSURE THAT THE TRANS-
MISSION IS IN THE PARK POSITION WITH THE
PARKING BRAKE APPLIED. THIS MAY RESULT IN
PERSONAL INJURY OR DEATH.
(1) Verify battery condition. Battery must be in
good condition with a full charge before performing
any starter tests. Refer to Battery Tests.
RSSTARTING8F-33
STARTING (Continued)
HEATED SEAT SYSTEM
TABLE OF CONTENTS
page page
HEATED SEAT SYSTEM
DESCRIPTION..........................7
OPERATION............................8
DIAGNOSIS AND TESTING
HEATED SEAT SYSTEM.................8
HEATED SEAT SWITCH
DESCRIPTION..........................8
OPERATION............................9
DIAGNOSIS AND TESTING
DRIVER HEATED SEAT SWITCH..........9
REMOVAL.............................10
INSTALLATION.........................10HEATED SEAT ELEMENTS
DESCRIPTION.........................11
OPERATION...........................11
DIAGNOSIS AND TESTING
HEATED SEAT ELEMENTS..............11
REMOVAL.............................12
INSTALLATION.........................12
HEATED SEAT SENSOR
DESCRIPTION.........................13
OPERATION...........................13
DIAGNOSIS AND TESTING
HEATED SEAT SENSOR................13
HEATED SEAT SYSTEM
DESCRIPTION
Vehicles with the heated seat option can be visu-
ally identified by the two separate heated seat
switches located in the instrument panel center
stack, just above the radio (Fig. 1). The heated seat
system allows the front seat driver and passenger to
select from two different levels of supplemental elec-
trical seat heating (HI/LO), or no seat heating to suit
their individual comfort requirements. The heated
seat system for this vehicle includes the following
major components:
²Heated Seat Elements- Four heated seat ele-
ments are used per vehicle, two for each front seat.
One heated seat element is integral to each front
seat trim cover, one in the seat back and one in the
seat bottom (cushion). Service replacement heating
elements are available, (Refer to 8 - ELECTRICAL/
HEATED SEATS/HEATED SEAT ELEMENT -
DESCRIPTION) for additional information.
²Heated Seat Modules- Two heated seat mod-
ules are used per vehicle. One module is mounted to
each of the seat cushion pans, located under the for-
ward edge of each front seat. (Refer to 8 - ELECTRI-
CAL/ELECTRONIC CONTROL MODULES/
MEMORY HEATED SEAT/MIRROR MODULE -
DESCRIPTION) for additional information.
²Heated Seat Sensors- Two heated seat sen-
sors are used per vehicle, one for each front seat. The
heated seat sensors are integral to each of the heated
seat bottoms (cushions).
²Heated Seat Switch- Two heated seat
switches are used per vehicle, one for the driver and
one for the passenger side front seats. The switches
are mounted in the instrument panel center stack.
(Refer to 8 - ELECTRICAL/HEATED SEATS/
DRIVER HEATED SEAT SWITCH - DESCRIPTION)
for additional information.
Fig. 1 HEATED SEAT SWITCH LOCATIONS
1 - HEATED SEAT SWITCHES
RSHEATED SEAT SYSTEM8G-7
OPERATION
There are three positions that can be selected with
each of the heated seat switches: Off, Low, or High.
When the left side of the switch rocker is fully
depressed, the Low position is selected and the low
position LED indicator illuminates. When the right
side of the switch rocker is fully depressed, the High
position is selected and the high position LED indi-
cator illuminates. When the switch rocker is moved
to its neutral position (middle), Off is selected and
both LED indicators are extinguished.
Each switch provides separate resistor, hard wire
inputs to its respective Heated Seat Module (HSM) to
indicate the selected switch position. The heated seat
module responds to the heated seat switch status
messages by controlling the output to the seat heater
elements of the selected seat. The Low heat position
set point is about 36É C (97É F), and the High heat
position set point is about 41É C (105É F).
DIAGNOSIS AND TESTING
DRIVER HEATED SEAT SWITCH
Refer to the appropriate wiring information for
complete circuit schematic or connector pin-out infor-
mation.
WARNING: REFER TO THE RESTRAINTS SECTION
OF THIS MANUAL BEFORE ATTEMPTING ANY
STEERING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
CHECKING SWITCH SIGNAL AND WIRING AT THE
MODULE
(1) Disconnect and isolate the battery negative
cable.
(2) Access and disconnect the gray 4-way connector
from the heated seat module. Visually inspect wiring
terminals for damage that would prevent positive
connection. If not OK, repair or replace the necessary
components.(3) Connect the battery negative cable. Place the
heated seat switch in the LO position. Using an
Ohmmeter, check the resistance between cavities 2
and 3 of the gray connector noted above. Resistance
should be about 3.5 kilohms (3500 ohms). If not OK,
check resistance directly at switch, as noted below. If
OK, proceed to the next step. If not OK, replace the
faulty switch.
(4) Place the heated seat switch in the HI position.
Using an ohmmeter, check the resistance between
cavities 2 and 3 of the gray connector noted above.
Resistance should be about 1.4 kilohms (1400 ohms).
If not OK, check resistance directly at the switch, as
indicated in the Heated Seat Switch Test Table. If
OK, proceed. If not OK replace the faulty switch.
(5) With the system ON in the HI position, check
for battery voltage and ground at cavities 4 and 1. If
OK, proceed with testing remaining components. If
not OK, repair open or shorted wiring.
CHECKING SWITCH ONLY
(1) Disconnect and isolate the battery negative
cable. Remove the center bezel from the instrument
panel (Refer to 23 - BODY/INSTRUMENT PANEL/
INSTRUMENT PANEL CENTER BEZEL -
REMOVAL). Check for continuity between the
ground circuit cavity (#10) of the instrument panel
center bezel switch electrical connector and a good
ground. There should be continuity. If OK, go to Step
2. If not OK, repair the open ground circuit to ground
as required.
(2) Connect the battery negative cable. Turn the
ignition switch to the On position. Check for battery
voltage at the fused ignition switch output (run) cir-
cuit cavity of the instrument panel center bezel
switch electrical connector (#4). If OK, turn the igni-
tion switch to the Off position, and go to Step 3. If
not OK, repair the open fused ignition switch output
(run) circuit as required.
(3) Test the heated seat switch as shown in the
Heated Seat Switch Test chart and the connector pin-
out below (Fig. 3). If OK, go to Step 4. If not OK,
replace the instrument panel center bezel switch
assembly.
RSHEATED SEAT SYSTEM8G-9
HEATED SEAT SWITCH (Continued)
DRIVER HEATED SEAT SWITCH TEST
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
(OHMS)
Off Pin4&5OPEN
Low Pin4&53570
High Pin4&51430
All resistance values are 1%.
PASSENGER HEATED SEAT SWITCH TEST
SWITCH
POSITIONRESISTANCE
BETWEENRESISTANCE
(OHMS)
Off Pin3&4OPEN
Low Pin3&43570
High Pin3&41430
All resistance values are 1%.
(4) Connect the instrument panel center bezel
switch and test the heated seat system for proper
operation. If the system is still inoperative proceed
with checking remaining components.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO THE RESTRAINTS SECTION OF
THIS MANUAL BEFORE ATTEMPTING ANY STEER-
ING WHEEL, STEERING COLUMN, SEAT OR
INSTRUMENT PANEL COMPONENT DIAGNOSIS OR
SERVICE. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the instrument panel center bezel,
(Refer to 23 - BODY/INSTRUMENT PANEL/IN-
STRUMENT PANEL CENTER BEZEL - REMOVAL).
(3) Remove the three screws (Fig. 4) that secure
the heated seat switch to the back of the instrument
panel center bezel.
(4) Remove the heated seat switch from the back
of the instrument panel center bezel.
INSTALLATION
(1) Position the heated seat switch onto the back
of the instrument panel center bezel.
(2) Install and tighten the three screws (Fig. 5)
that secure the heated seat switch to the back of the
instrument panel center bezel. Tighten the screws to
1.5 N´m (13 in. lbs.).
Fig. 3 Instrument Panel Center Bezel Switch
Connector
Fig. 4 SWITCH RETAINING SCREWS
1 - HEATED SEAT SWITCH ASSEMBLY
2 - RETAINING SCREWS
8G - 10 HEATED SEAT SYSTEMRS
HEATED SEAT SWITCH (Continued)