engine overheat CHRYSLER VOYAGER 1996 Service Manual

CLUTCH DIAGNOSIS
Problem diagnosis will generally require a road
test to determine the type of fault. Component
inspection will then determine the problem after road
testing.
Drive the vehicle at normal speeds during road
test. Shift the transaxle through all gear ranges andobserve clutch action. If chatter, grab, slip, or
improper release is experienced, remove and inspect
the clutch components. If the problem is noise or
hard shifting, further diagnosis may be needed. The
transaxle or other driveline components may actually
be at fault.
SERVICE DIAGNOSIS±CLUTCH GRAB/CHATTER
CONDITION POSSIBLE CAUSES CORRECTION
CLUTCH DISC FACING
COVERED WITH OIL OR
GREASEOil leak at engine rear main or transaxle
input shaft sealCorrect leak and replace clutch assembly
NO FAULT FOUND WITH
CLUTCH
COMPONENTSProblem actually related to suspension
or driveline componentFurther diagnosis required. Check
engine/transmission mounts, suspension
attaching parts and other driveline
components as needed.
Engine related problems Check EFI and ignition systems
PARTIAL ENGAGEMENT
OF CLUTCH DISCClutch cover, spring, or release fingers
bent, distorted (rough handling, improper
assembly)Replace clutch assembly
Clutch disc damaged or distorted Replace clutch assembly
Clutch misalignment Check alignment and runout of flywheel,
disc, or cover. Check clutch housing to
engine dowels and dowel holes for
damage. Correct as necessary.
SERVICE DIAGNOSIS±CLUTCH SLIPS
CONDITION POSSIBLE CAUSES CORRECTION
DISC FACING WORN
OUTNormal wear. Replace clutch assembly.
Driver frequently rides (slips) clutch,
results in rapid wear overheating.Replace clutch assembly
Insufficient clutch cover diaphragm
spring tensionReplace clutch assembly
CLUTCH DISC FACING
CONTAMINATED WITH
OIL OR GREASELeak at rear main oil seal or transaxle
input shaft sealReplace leaking seals. Replace clutch
assembly.
Road splash, water entering housing Seal housing. Inspect clutch assembly.
CLUTCH IS RUNNING
PARTIALLY
DISENGAGEDRelease bearing sticking or binding,
does not return to normal running
position.Verify that bearing is actually binding.
Then, replace bearing and transmission
front bearing retainer if sleeve surface is
damaged.
Cable self-adjuster mechanism sticking
or binding causing high preload (LHD
Applications only)Verify that self-adjuster is free to move
(LHD Applications only)
CLUTCH DISC FACINGS
HAVE FRACTURED INTO
SMALL PIECESDriver performs a 5-1 downshift at
vehicle speed in excess of 60 miles per
hourAlert driver to problem cause. Replace
clutch assembly.
Excessive heat from slippage Replace clutch assembly
6 - 6 CLUTCHNS/GS
DIAGNOSIS AND TESTING (Continued)

If the gasket is dirty or damaged, a vacuum
may not be achieved, resulting is loss of coolant
and eventual overheating due to low coolant
level in radiator and engine.
ENGINE BLOCK HEATER
The engine block heater is available as an optional
accessory on all models. The heater is operated by
ordinary house current (110 Volt A.C.) through a
power cord located behind the radiator grille. This
provides easier engine starting and faster warm-up
when vehicle is operated in areas having extremely
low temperatures. The heater is mounted in a core
hole (in place of a core hole plug) in the engine block,
with the heating element immersed in coolant.
Fig. 7 Cooling ModuleÐ3.0L (Front A/C Only)
Fig. 8 Cooling ModuleÐ3.0/3.3/3.8L (With Rear A/C)
Fig. 9 Radiator Pressure Cap Filler Neck
NSCOOLING SYSTEM 7 - 5
GENERAL INFORMATION (Continued)

RADIATOR COOLANT FLOW TEST
To determine whether coolant is flowing through
the cooling system, use the following procedure:
(1) If engine is cold, idle engine until normal oper-
ating temperature is reached. Then feel the upper
radiator hose. If it is hot, coolant is circulating.
WARNING: DO NOT REMOVE RADIATOR PRES-
SURE CAP WITH THE SYSTEM HOT AND UNDER
PRESSURE BECAUSE SERIOUS BURNS FROM
COOLANT CAN OCCUR.
(2) Remove radiator pressure cap when engine is
cold, idle engine until thermostat opens, you should
observe coolant flow while looking down the filler
neck. Once flow is detected install radiator pressure
cap.
RADIATOR FAN CONTROL
Fan control is accomplished two ways. A pressure
transducer on the compressor discharge line sends a
signal to the Powertrain Control Module (PCM)
which will activate the fan. In addition to this con-
trol, the fan is turned on by the temperature of the
coolant which is sensed by the coolant temperature
sensor which sends the message to the PCM. The fan
will not run during cranking until the engine starts
no matter what the coolant temperature is.
CAUTION: The solid state fan relay is attached to
the left frame rail near the lower radiator support.
The relay bracket, and fastener are used to dissi-
pate heat from the relay. Ensure the relay is prop-
erly attached to prevent the following:
²Intermittent engine overheating.
²Relay ªthermalº shutdown, or relay damage.
ELECTRIC FAN MOTOR TEST
Refer to Powertrain Diagnostic Manual for proce-
dure.
TESTING COOLING SYSTEM FOR LEAKS
With engine not running, wipe the radiator filler
neck sealing seat clean. The radiator should be full.
Attach the Radiator Pressure Tool to the radiator,
as shown in (Fig. 12) and apply 104 kPa (15 psi)
pressure. If the pressure drops more than 2 psi in 2
minutes, inspect all points for external leaks.
All radiator and heater hoses should be shaken
while at 104 kPa (15 psi), since some leaks occur only
while driving due to engine movement.
If there are no external leaks, after the gauge dial
shows a drop in pressure, detach the tester. Start
engine and run the engine up to normal operating
temperature to open the thermostat and allow the
coolant to expand. Reattach the tester. If the needleon the dial fluctuates it indicates a combustion leak,
usually a head gasket leak.
RADIATOR FAN OPERATION
Radiator Fan Control A/C Pressure
Fan
Operation
Low
Fan
Speed
30%High
Fan
Speed
100%Low
Fan
Speed
30%High
Fan
Speed
100%
On: 104ÉC
(220ÉF)110ÉC
(230ÉF)
Fan
Speed
Duty-
Cycles
(Ramps-
up) from
31% to
99%1,724
Kpa
(250
psi)2,068
Kpa
(300
psi)Fan
Speed
Duty-
Cycles
(Ramps-
up) from
31% to
99%
Off: 101ÉC
(214ÉF)Fan
Speed
Duty-
Cycles
(Ramps-
down)
from
99% to
31%1,710
Kpa
(248
psi)Fan
Speed
Duty-
Cycles
(Ramps-
down)
from
99% to
31%
Fig. 12 Pressure Testing Cooling System
7 - 14 COOLING SYSTEMNS
DIAGNOSIS AND TESTING (Continued)

NOTE: Do not use any type of tool when tighten-
ing the cap. Hand tighten only (approximately 5 N´m
or 44 in. lbs.) torque.
COOLANT PERFORMANCE
ETHYLENE-GLYCOL MIXTURES
The required ethylene-glycol (antifreeze) and water
mixture depends upon the climate and vehicle oper-
ating conditions. The recommended mixture of 50/50
ethylene-glycol and water will provide protection
against freezing to -37 deg. C (-35 deg. F). The anti-
freeze concentrationmust alwaysbe a minimum of
44 percent, year-round in all climates.If percentage
is lower than 44 percent, engine parts may be
eroded by cavitation, and cooling system com-
ponents may be severely damaged by corrosion.
Maximum protection against freezing is provided
with a 68 percent antifreeze concentration, which
prevents freezing down to -67.7 deg. C (-90 deg. F). A
higher percentage will freeze at a warmer tempera-
ture.100 Percent Ethylene-GlycolÐShould Not Be Used in
Chrysler Vehicles
Use of 100 percent ethylene-glycol will cause for-
mation of additive deposits in the system, as the cor-
rosion inhibitive additives in ethylene-glycol require
the presence of water to dissolve. The deposits act as
insulation, causing temperatures to rise to as high as
149 deg. C (300) deg. F). This temperature is hot
enough to melt plastic and soften solder. The
increased temperature can result in engine detona-
tion. In addition, 100 percent ethylene-glycol freezes
at 22 deg. C (-8 deg. F ).
Propylene-glycol FormulationsÐShould Not Be Used in
Chrysler Vehicles
Propylene-glycol formulations do not meet
Chrysler coolant specifications.It's overall effec-
tive temperature range is smaller than that of ethyl-
ene-glycol. The freeze point of 50/50 propylene-glycol
and water is -32 deg. C (-26 deg. F). 5 deg. C higher
than ethylene-glycol's freeze point. The boiling point
(protection against summer boil-over) of propylene-
glycol is 125 deg. C (257 deg.F)at96.5 kPa (14 psi),
compared to 128 deg. C (263 deg. F) for ethylene-gly-
col. Use of propylene-glycol can result in boil-over or
freeze-up in Chrysler vehicles, which are designed for
ethylene-glycol. Propylene glycol also has poorer heat
transfer characteristics than ethylene glycol. This
can increase cylinder head temperatures under cer-
tain conditions.
Propylene-glycol/Ethylene-glycol MixturesÐShould Not Be
Used in Chrysler Vehicles
Propylene-glycol/ethylene-glycol Mixtures can
cause the destabilization of various corrosion inhibi-
tors, causing damage to the various cooling system
components. Also, once ethylene-glycol and propy-
lene-glycol based coolants are mixed in the vehicle,
conventional methods of determining freeze point will
not be accurate. Both the refractive index and spe-
cific gravity differ between ethylene glycol and propy-
lene glycol.
CAUTION: Richer antifreeze mixtures cannot be
measured with normal field equipment and can
cause problems associated with 100 percent ethyl-
ene-glycol.
BELT TENSION
Correct accessory drive belt tension is required to
be sure of optimum performance of belt driven engine
accessories. If specified tension is not maintained,
belt slippage may cause; engine overheating, lack of
power steering assist, loss of air conditioning capac-
ity, reduced generator output rate and greatly
reduced belt life.
Fig. 11 Coolant Tank Pressure/Vent Cap
NS/GSCOOLING SYSTEM 7 - 5
DESCRIPTION AND OPERATION (Continued)

CAUTION: Before performing any starter tests, the
ignition and fuel systems must be disabled.
(1) Connect a volt-ampere tester to the battery ter-
minals (Fig. 7). Refer to the operating instructions
provided with the tester being used.
(2) To disable the ignition and fuel systems, dis-
connect the Automatic Shutdown Relay (ASD). The
ASD relay is located in the Power Distribution Cen-
ter (PDC). Refer to the PDC cover for proper relay
location. The 2.5L Diesel Engine, to disable the
engine from starting, disconnect wire connector from
the Fuel Solenoid.
(3) Verify that all lights and accessories are OFF,
and the transmission shift selector is in the PARK
position or with the clutch pedal depressed and SET
parking brake.
CAUTION: Do not overheat the starter motor or
draw the battery voltage below 9.6 volts during
cranking operations.
(4) Rotate and hold the ignition switch in the
START position. Observe the volt-ampere tester (Fig.
6).
²If voltage reads above 9.6 volts, and amperage
draw reads above 280 amps or the Diesel engine
above 450 amps, check for engine seizing or faulty
starter.
²If voltage reads 12.4 volts or greater and amper-
age reads 0 to 10 amps, check for corroded cables
and/or bad connections.
²Voltage below 9.6 volts and amperage draw
above 300 amps or Diesel engine above 500 amps,
the problem is the starter. Replace the starter refer
to starter removal.
(5) After the starting system problems have been
corrected, verify the battery state-of-charge and
charge battery if necessary. Disconnect all testingequipment and connect ASD relay or the Fuel Sole-
noid. Start the vehicle several times to assure the
problem has been corrected.
REMOVAL AND INSTALLATION
STARTERÐ2.4L ENGINE
REMOVAL
(1) Release hood latch and open hood.
(2) Disconnect battery negative cable (Fig. 8).
(3) Hoist and support vehicle on safety stands.
(4) Disconnect solenoid wire connector from termi-
nal.
(5) Remove nut holding B+ wire to terminal.
(6) Disconnect solenoid and B+ wires from starter
terminals.
(7) Remove bolts holding starter to transaxle bell-
housing (Fig. 9).
(8) Remove starter.
Fig. 7 Volt-Ampere Tester Connections
Fig. 8 Battery Negative Cable
Fig. 9 Starter±2.4L Engine
NSSTARTER 8B - 5
DIAGNOSIS AND TESTING (Continued)

plugs.Ash encrusted spark plugs can be cleaned
and reused.
HIGH SPEED MISS
When replacing spark plugs because of a high
speed miss condition;wide open throttle opera-
tion should be avoided for approximately 80 km
(50 miles) after installation of new plugs.This
will allow deposit shifting in the combustion chamber
to take place gradually and avoid plug destroying
splash fouling shortly after the plug change.
ELECTRODE GAP BRIDGING
Loose deposits in the combustion chamber can
cause electrode gap bridging. The deposits accumu-
late on the spark plugs during continuous stop-
and-go driving. When the engine is suddenly
subjected to a high torque load, the deposits partially
liquefy and bridge the gap between the electrodes
(Fig. 25). This short circuits the electrodes.Spark
plugs with electrode gap bridging can be
cleaned and reused.
SCAVENGER DEPOSITS
Fuel scavenger deposits may be either white or yel-
low (Fig. 26). They may appear to be harmful, but
are a normal condition caused by chemical additives
in certain fuels. These additives are designed to
change the chemical nature of deposits and decrease
spark plug misfire tendencies. Notice that accumula-
tion on the ground electrode and shell area may be
heavy but the deposits are easily removed.Spark
plugs with scavenger deposits can be consid-
ered normal in condition, cleaned and reused.
CHIPPED ELECTRODE INSULATOR
A chipped electrode insulator usually results from
bending the center electrode while adjusting the
spark plug electrode gap. Under certain conditions,
severe detonation also can separate the insulator
from the center electrode (Fig. 27).Spark plugs
with chipped electrode insulators must be
replaced.
PREIGNITION DAMAGE
Excessive combustion chamber temperature can
cause preignition damage. First, the center electrode
dissolves and the ground electrode dissolves some-
what later (Fig. 28). Insulators appear relatively
deposit free. Determine if the spark plugs are the
correct type, as specified on the VECI label, or if
other operating conditions are causing engine over-
heating.
SPARK PLUG OVERHEATING
Overheating is indicated by a white or gray center
electrode insulator that also appears blistered (Fig.
Fig. 24 Oil or Ash Encrusted
Fig. 25 Electrode Gap Bridging
Fig. 26 Scavenger Deposits
8D - 12 IGNITION SYSTEMNS
DIAGNOSIS AND TESTING (Continued)

(2) Inspect BCM connectors and wires for proper
connection. If OK, replace BCM for tone condition.
DOME LAMP ON CHIME
The dome lamp on chime will warn the driver that
the dome lamps have been left on.
With the ignition is OFF:
²Driver's door OPEN (door ajar switch is closed to
ground)
²Dome lamps are ON (dome lamp switch is closed
to ground),
The chime will sound continuously until driver's
door is closed, dome lamps tuned OFF or until the
battery protection time out of 15 minutes has
expired. Refer Group 8L, Lamps proper procedures.
Chime rate: 168 to 192 chimes per minute.
ENGINE TEMPERATURE CRITICAL CHIME
The engine temperature critical chime will warn
the driver that the vehicle's engine is overheating.
While monitoring the coolant temperature, the Pow-
ertrain Control Module (PCM) will send on the CCD
bus as engine temperature every 1.376 seconds to the
Body Control Module (BCM). The BCM calculates
engine temperature and determines if a warning
should occur. This feature is functional only with the
Ignition Switch in the Run/Start position.
When the engine temperature reaches 122ÉC
(252ÉF) the BCM will chime one tone and the engine
temperature lamp comes ON. The BCM turns OFF
the lamp when the engine temperature reaches
117ÉC (242ÉF). The BCM will chime continuously
when the engine temperature reaches 125ÉC (257ÉF).
The chime will turn OFF after four minutes or when
the temperature reaches 117ÉC (242ÉF), which ever
occurs first.
EXTERIOR LAMPS ON CHIME
The exterior lamp on chime will warn the driver
that the exterior lights have been left on.
With the ignition switch OFF:
²Driver's door is open (door ajar switch is closed
to ground)
²Parking lamps or headlamps ON (parking lamp
switch is closed to ground)
The chime will sound until lights are turned OFF,
driver's door closed or until the battery protection
time out of 3 minutes has expired.
Refer to Group 8L, Lamps, for proper service pro-
cedures. Chime rate: 168 to 192 chimes per minute.
To test the exterior lamps left on function:
²Turn ignition off
²Remove ignition key
²Turn exterior lamps on with driver's door open.
Chime should sound until lamps are turned off or
driver's door is closed.
KEY-IN IGNITION CHIME
The key-in ignition chime will act as a warning to
the driver that the ignition key has been left in the
ignition switch.
With the ignition switch is in OFF position ONLY:
²Driver's door is open/ajar (door ajar switch is
closed to ground)
²Key is in the ignition switch (key-in ignition
switch is closed to ground)
The chime will sound until one of the above condi-
tions is removed. Chime rate: 168 to 192 chimes per
minute.
To test the key-in ignition function, insert key into
the ignition and open driver's door. Do not turn igni-
tion ON. Chime should sound until key is removed
from ignition or driver's door is closed.
LOW OIL PRESSURE CHIME OPERATION
The low oil pressure chime will warn the driver
that the engine oil pressure is low. The oil pressure
switch, will close to ground during a low oil pressure
condition. The oil pressure lamp will illuminate in
the message center. The body control module will
monitor the oil pressure switch and signal a low oil
pressure condition. A continuous four minute warn-
ing chime will sound and the oil pressure lamp will
come ON when the following conditions are met:
²Ignition on and engine not cranking
²Engine running at 420 to 480 rpm for 10 sec-
onds
²Oil pressure switch closed to ground for (1 sec-
ond minimum, 2 seconds maximum)
Chime rate: 168 to 192 chimes per minute.
SEAT BELT CHIME
The seat belt chime will sound for 4 to 8 seconds,
when the ignition is turned on and the driver's seat
belt is not buckled (seat belt switch is closed to
ground). This is a reminder to the driver to buckle
the seat belt. The seat belt lamp is controlled by the
mechanical instrument cluster. The cluster will also
illuminate the seat belt warning lamp for 6 seconds.
Buckling the driver's seat belt before the time out
has expired will cause the chime to stop immediately.
Chime rate: 38 to 62 chimes per minute.
To test the seat belt warning system, the ignition
switch must be in the OFF position for 1 minute
before starting the test. Turn the ignition switch to
the on position with the driver's seat belt not buck-
led. The seat belt warning lamp should light and the
chime should sound 4 to 8 seconds.
SEAT BELT LAMP
The seat belt lamp in the instrument cluster sig-
nals the vehicle passengers to fasten their seat belts.
The seat belt lamp is illuminated directly by the
8U - 2 CHIME WARNING/REMINDER SYSTEMNS
DIAGNOSIS AND TESTING (Continued)

CHIME WARNING/REMINDER SYSTEM
CONTENTS
page page
GENERAL INFORMATION
INTRODUCTION........................ 1
DIAGNOSIS AND TESTING
CATALYST OVERHEAT WARNING CHIME.... 1
CHIME SYSTEM DIAGNOSIS.............. 1
DOME LAMP ON CHIME................. 2
ENGINE TEMPERATURE CRITICAL CHIME . . . 2EXTERIOR LAMPS ON CHIME............. 2
KEY-IN IGNITION CHIME................. 2
LOW OIL PRESSURE CHIME OPERATION . . . 2
SEAT BELT CHIME...................... 3
SEAT BELT LAMP...................... 3
TURN SIGNAL ON CHIME................ 3
WARNING LAMP ANNOUNCEMENT CHIME . . 3
GENERAL INFORMATION
INTRODUCTION
WARNING: ON VEHICLES EQUIPPED WITH AN
AIRBAG, REFER TO GROUP 8M, RESTRAINT SYS-
TEMS FOR SAFETY PRECAUTIONS AND WARN-
INGS TO OBSERVE WHEN SERVICING AIRBAG
RELATED COMPONENTS.
The chime system provides the driver with warn-
ing chimes for:
²Seat Belt
²Exterior Lamps ON
²Key-In Ignition
²Engine Temperature Critical
²Turn Signals ON
²Dome Lamp ON
²Low Oil Pressure
²High Speed Warning
²Warning Lamp Announcement
²Catalyst Overheating
The Chime Warning/Reminder System is diagnosed
using a scan tool (DRB). Refer to the proper Body
Diagnostic Procedures manual for testing procedures
and scan tool usage instructions.
DIAGNOSIS AND TESTING
CATALYST OVERHEAT WARNING CHIME
The Catalyst Overheat Warning Chime will act as
a warning to the driver that the vehicle's catalyst
has entered an overheat condition. The Powertrain
Control Module (PCM) will enable or disable this fea-
ture for the appropriate vehicles. Right hand drive
gas vehicles only. The Body Control Module (BCM)
will monitor the CCD bus for status and signal a cat-
alyst overheat condition with continuous warning
chime when the following conditions are met:²Ignition switch in the ON position
²Engine running at 420 to 480 rpm for 10 sec-
onds
²CCD status and with a chime rate of one chime
per second.
CHIME SYSTEM DIAGNOSIS
NO TONE WHEN IGNITION SWITCH IS
TURNED ON AND DRIVER'S SEAT BELT IS
NOT BUCKLED.
(1) Using a scan tool (DRB), check for tone in any
other function.
(2) Using a voltmeter, check for voltage:
(a) Pin 9 of the internal 32 way connector of the
BCM for battery feed.
(b) Pin 8 of the internal 32 way connector of the
BCM for ignition feed.
(c) If voltage OK, go to step Step 3
(d) If NO voltage repair as necessary. Refer to
Group 8W, Wiring Diagrams for component loca-
tions and circuit information.
(3) Check driver's seat belt buckle switch input for
a closed circuit when not buckled. If input not seen,
look for open in wiring or switch. The switch is
grounded when belt is not buckled.
(4) Repair as necessary.
NO FASTEN SEAT BELT LAMP WHEN
IGNITION SWITCH IS TURNED ON.
(1) Check for burned out lamp.
(2) Using a voltmeter check for voltage:
(a) Pin 2 of the mechanical instrument cluster
for battery feed.
(b) Pin 11 of the mechanical instrument cluster
for ignition voltage.
(3) Repair as necessary.
NS/GSCHIME WARNING/REMINDER SYSTEM 8U - 1

FASTEN SEAT BELT LAMP OR TONE
CONTINUES FOR MORE THAN 10 SECONDS
AFTER SEAT BELTS ARE FASTENED AND
DRIVER'S DOOR IS CLOSED.
(1) Check left door ajar switch for no ground when
switch is depressed.
(a) If continuity replace door ajar switch.
(b) If NO continuity replace BCM for tone condi-
tion, or replace mechanical instrument panel for
lamp condition.
(c) Replace BCM for tone condition.
(d) Replace mechanical instrument cluster for
lamp condition.
NO TONE WHEN PARK OR HEADLAMPS ARE
ON AND DRIVER'S DOOR IS OPEN.
(1) Check left door ajar switch for good ground
when driver's door is open. Repair as necessary.
(2) Inspect BCM connectors and wires for proper
connection. If OK, replace BCM for tone condition.
DOME LAMP ON CHIME
The dome lamp on chime will warn the driver that
the dome lamps have been left on.
With the ignition is OFF:
²Driver's door OPEN (door ajar switch is closed to
ground)
²Dome lamps are ON (dome lamp switch is closed
to ground),
The chime will sound continuously until driver's
door is closed, dome lamps tuned OFF or until the
battery protection time out of 15 minutes has
expired. Refer Group 8L, Lamps proper procedures.
Chime rate: 168 to 192 chimes per minute.
ENGINE TEMPERATURE CRITICAL CHIME
The engine temperature critical chime will warn
the driver that the vehicle's engine is overheating.
While monitoring the coolant temperature, the Pow-
ertrain Control Module (PCM) will send on the CCD
bus as engine temperature every 1.376 seconds to the
Body Control Module (BCM). The BCM calculates
engine temperature and determines if a warning
should occur. This feature is functional only with the
Ignition Switch in the Run/Start position. On the
Diesel vehicles, the coolant temperature sensor is
read directly by the BCM.
When the engine temperature reaches 122ÉC
(252ÉF) or the diesel engine 112ÉC (234ÉF), the BCM
will chime one tone and the engine temperature lamp
comes ON. The BCM turns OFF the lamp when the
engine temperature reaches 117ÉC (242ÉF) or the die-
sel engine 108ÉC (226ÉF). The BCM will chime con-
tinuously when the engine temperature reaches
125ÉC (257ÉF) or diesel engine 116ÉC (241ÉF). The
chime will turn OFF after four minutes or when thetemperature reaches 117ÉC (242ÉF) or diesel engine
108ÉC (226ÉF), which ever occurs first.
EXTERIOR LAMPS ON CHIME
The exterior lamp on chime will warn the driver
that the exterior lights have been left on.
With the ignition switch OFF:
²Driver's door is open (door ajar switch is closed
to ground)
²Parking lamps or headlamps ON (parking lamp
switch is closed to ground)
The chime will sound until lights are turned OFF,
driver's door closed or until the battery protection
time out of 3 minutes has expired.
Refer to Group 8L, Lamps, for proper service pro-
cedures. Chime rate: 168 to 192 chimes per minute.
To test the exterior lamps left on function:
²Turn ignition off
²Remove ignition key
²Turn exterior lamps on with driver's door open.
Chime should sound until lamps are turned off or
driver's door is closed.
KEY-IN IGNITION CHIME
The key-in ignition chime will act as a warning to
the driver that the ignition key has been left in the
ignition switch.
With the ignition switch is in OFF position ONLY:
²Driver's door is open/ajar (door ajar switch is
closed to ground)
²Key is in the ignition switch (key-in ignition
switch is closed to ground)
The chime will sound until one of the above condi-
tions is removed. Chime rate: 168 to 192 chimes per
minute.
To test the key-in ignition function, insert key into
the ignition and open driver's door. Do not turn igni-
tion ON. Chime should sound until key is removed
from ignition or driver's door is closed.
LOW OIL PRESSURE CHIME OPERATION
The low oil pressure chime will warn the driver
that the engine oil pressure is low. The oil pressure
switch, will close to ground during a low oil pressure
condition. The oil pressure lamp will illuminate in
the message center. The body control module will
monitor the oil pressure switch and signal a low oil
pressure condition. A continuous four minute warn-
ing chime will sound and the oil pressure lamp will
come ON when the following conditions are met:
²Ignition on and engine not cranking
²Engine running at 420 to 480 rpm for 10 sec-
onds
²Oil pressure switch closed to ground for (1 sec-
ond minimum, 2 seconds maximum)
Chime rate: 168 to 192 chimes per minute.
8U - 2 CHIME WARNING/REMINDER SYSTEMNS/GS
DIAGNOSIS AND TESTING (Continued)

AIR CONDITIONING (A/C) CONTROLSÐPCM
INPUTS
The A/C control system information applies to fac-
tory installed air conditioning units.
A/C REQUEST SIGNAL:When either the A/C or
Defrost mode has been selected and the A/C low and
high±pressure switches are closed, an input signal is
sent to the powertrain control module (PCM). The
PCM uses this input to cycle the A/C compressor
through the A/C relay.
If the A/C low or high±pressure switch opens, the
PCM will not receive an A/C request signal. The
PCM will then remove the ground from the A/C relay.
This will deactivate the A/C compressor clutch. Also,
if the engine coolant reaches a temperature outside
normal of its normal range, or it overheats, the PCM
will deactivate the A/C clutch.
BRAKE SWITCHÐPCM INPUT
When the brake light switch is activated, the PCM
receives an input indicating that the brakes are
being applied. After receiving this input, the PCM is
used to control the speed control system. There is a
Primary and a Secondary brake switch. The Second-
ary brake switch is closed until the brake pedal is
pressed.
DATA LINK CONNECTORÐPCM INPUT AND
OUTPUT
The 16±way data link connector (diagnostic scan
tool connector) links the Diagnostic Readout Box(DRB) scan tool with the PCM. The data link connec-
tor is located under the instrument panel near the
bottom of steering column (Fig. 7).
VEHICLE SPEED SENSORÐPCM INPUT
The vehicle speed sensor (Fig. 8) is located in the
extension housing of the transmission. The sensor
input is used by the PCM to determine vehicle speed
and distance traveled.
Fig. 6 Speed Sensor Operation
Fig. 7 Data Link Connector Location
Fig. 8 Vehicle Speed SensorÐTypical
NS/GSFUEL SYSTEMÐ2.5L DIESEL ENGINE/2.0L GAS ENGINE 14 - 47
DESCRIPTION AND OPERATION (Continued)