MERCEDES-BENZ SPRINTER 2005 Service Repair Manual

ACCESSORY DRIVE
TABLE OF CONTENTS
page page
BELT TENSIONERS
DESCRIPTION..........................5
OPERATION............................5
DRIVE BELTS
DIAGNOSIS AND TESTING - ACCESSORY
DRIVE BELT..........................5REMOVAL.............................8
INSTALLATION..........................8
BELT TENSIONERS
DESCRIPTION
CAUTION: Do not attempt to check belt tension with
a belt tension gauge on vehicles equipped with an
automatic belt tensioner.
Drive belts on all engines are equipped with a
spring loaded automatic belt tensioner. This ten-
sioner maintains constant belt tension at all times
and requires no maintenance or adjustment.
OPERATION
WARNING: THE AUTOMATIC BELT TENSIONER
ASSEMBLY IS SPRING LOADED. DO NOT ATTEMPT
TO DISASSEMBLE THE TENSIONER ASSEMBLY.
The automatic belt tensioner maintains correct belt
tension using a coiled spring within the tensioner
housing. The spring applies pressure to the tensioner
arm pressing the arm into the belt, tensioning the
belt.
If a new belt is being installed, the arrow must be
within approximately 3 mm (1/8 in.) of indexing
mark. Belt is considered new if it has been used 15
minutes or less. If this specification cannot be met,
check for:
²The wrong belt being installed (incorrect length/
width)
²Worn bearings on an engine accessory (A/C com-
pressor, power steering pump, water pump, idler pul-
ley or generator)
²A pulley on an engine accessory being loose
²Misalignment of an engine accessory
²Belt incorrectly routed.
DRIVE BELTS
DIAGNOSIS AND TESTING - ACCESSORY
DRIVE BELT
VISUAL DIAGNOSIS
When diagnosing serpentine accessory drive belts,
small cracks that run across the ribbed surface of the
belt from rib to rib (Fig. 1), are considered normal.
These are not a reason to replace the belt. However,
cracks running along a rib (not across) arenotnor-
mal. Any belt with cracks running along a rib must
be replaced (Fig. 1). Also replace the belt if it has
excessive wear, frayed cords or severe glazing.
Fig. 1 Belt Wear Patterns
1 - NORMAL CRACKS BELT OK
2 - NOT NORMAL CRACKS REPLACE BELT
VAACCESSORY DRIVE 7 - 5

Refer to ACCESSORY DRIVE BELT DIAGNOSIS
CHART for further belt diagnosis.
NOISE DIAGNOSIS
Noises generated by the accessory drive belt are
most noticeable at idle. Before replacing a belt toresolve a noise condition, inspect all of the accessory
drive pulleys for contamination, alignment, glazing,
or excessive end play.
ACCESSORY DRIVE BELT DIAGNOSIS CHART
CONDITION POSSIBLE CAUSES CORRECTION
RIB CHUNKING (One or more ribs
has separated from belt body)1. Foreign objects imbedded in
pulley grooves.1. Remove foreign objects from
pulley grooves. Replace belt.
2. Installation damage 2. Replace belt
RIB OR BELT WEAR 1. Pulley misaligned 1. Align pulley(s)
2. Abrasive environment 2. Clean pulley(s). Replace belt if
necessary
3. Rusted pulley(s) 3. Clean rust from pulley(s)
4. Sharp or jagged pulley groove
tips4. Replace pulley. Inspect belt.
5. Belt rubber deteriorated 5. Replace belt
BELT SLIPS 1. Belt slipping because of
insufficient tension1. Inspect/Replace tensioner if
necessary
2. Belt or pulley exposed to
substance that has reduced friction
(belt dressing, oil, ethylene glycol)2. Replace belt and clean pulleys
3. Driven component bearing failure
(seizure)3. Replace faulty component or
bearing
4. Belt glazed or hardened from
heat and excessive slippage4. Replace belt.
LONGITUDAL BELT CRACKING 1. Belt has mistracked from pulley
groove1. Replace belt
2. Pulley groove tip has worn away
rubber to tensile member2. Replace belt
9GROOVE JUMPING9
(Belt does not maintain correct
position on pulley)1. Incorrect belt tension 1. Inspect/Replace tensioner if
necessary
2. Pulley(s) not within design
tolerance2. Replace pulley(s)
3. Foreign object(s) in grooves 3. Remove foreign objects from
grooves
4. Pulley misalignment 4. Align component
5. Belt cordline is broken 5. Replace belt
7 - 6 ACCESSORY DRIVEVA
DRIVE BELTS (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
BELT BROKEN
(Note: Identify and correct problem
before new belt is installed)1. Incorrect belt tension 1. Replace Inspect/Replace
tensioner if necessary
2. Tensile member damaged during
belt installation2. Replace belt
3. Severe misalignment 3. Align pulley(s)
4. Bracket, pulley, or bearing failure 4. Replace defective component
and belt
NOISE (Objectional squeal, squeek,
or rumble is heard or felt while drive
belt is in operation)1. Incorrect belt tension 1. Inspect/Replace tensioner if
necessary
2. Bearing noise 2. Locate and repair
3. Belt misalignment 3. Align belt/pulley(s)
4. Belt to pulley mismatch 4. Install correct belt
5. Driven component induced
vibration5. Locate defective driven
component and repair
6. System resonent frequency
induced vibration6. Vary belt tension within
specifications
TENSION SHEETING FABRIC
FAILURE
(Woven fabric on outside,
circumference of belt has cracked or
separated from body of belt)1. Tension sheeting contacting
stationary object1. Correct rubbing condition
2. Excessive heat causing woven
fabric to age2. Replace belt
3. Tension sheeting splice has
fractured3. Replace belt
CORD EDGE FAILURE
(Tensile member exposed at edges
of belt or separated from belt body)1. Incorrect belt tension 1. Inspect/Replace tensioner if
necessary
2. Belt contacting stationary object 2. Replace belt
3. Pulley(s) out of tolerance 3. Replace pulley
4. Insufficient adhesion between
tensile member and rubber matrix4. Replace belt
VAACCESSORY DRIVE 7 - 7
DRIVE BELTS (Continued)

REMOVAL
CAUTION: Do not attempt to check belt tension with
a belt tension gauge on vehicles equipped with an
automatic belt tensioner.
NOTE: The belt routing schematics are published
from the latest information available at the time of
publication. If anything differs between these sche-
matics and the Belt Routing Label, use the sche-
matics on Belt Routing Label.This label is located in
the engine compartment.
(1) A 3/8 inch square hole is provided in the auto-
matic belt tensioner. Attach a 3/8 inch drive-long
handle ratchet to this hole (Fig. 2).
(2) Rotate ratchet and tensioner assembly counter-
clockwise (as viewed from front) until tension has
been relieved from belt (Fig. 2).
(3) Remove belt from water pump pulley first.
(4) Remove belt from vehicle.
INSTALLATION
CAUTION: When installing the accessory drive belt,
the belt must be the correct length and routed cor-
rectly. If not, engine may overheat due to water
pump rotating in wrong direction.
(1) Position drive belt over all pulleysexcept
water pump pulley (Fig. 3).
(2) Attach a 3/8 inch ratchet to tensioner.
(3) Rotate ratchet and belt tensioner counterclock-
wise. Place belt over water pump pulley. Let ten-
sioner rotate back into place. Remove ratchet. Be
sure belt is properly seated on all pulleys.
Fig. 2 DRIVE BELT TENSIONER
1 - ACCESSORY DRIVE BELT TENSIONER
2 - RATCHET WRENCH
Fig. 3 ACCESSORY DRIVE BELT ROUTING
1 - A/C COMPRESSOR
2 - POWER STEERING
3 - DRIVE BELT TENSIONER
4 - CRANKSHAFT PULLEY
5 - WATER PUMP PULLEY
6 - GENERATOR
7 - IDLER PULLEY
7 - 8 ACCESSORY DRIVEVA
DRIVE BELTS (Continued)

ENGINE
TABLE OF CONTENTS
page page
COOLANT
DESCRIPTION..........................9
DIAGNOSIS AND TESTING - COOLING
SYSTEM LEAKS......................10
STANDARD PROCEDURE
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT.................11
STANDARD PROCEDURE - DRAINING
COOLING SYSTEM....................12
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM....................12
COOLANT LEVEL SENSOR
REMOVAL.............................13
INSTALLATION.........................13
RADIATOR FAN
REMOVAL.............................13
INSTALLATION.........................13
ENGINE BLOCK HEATER
REMOVAL.............................14
INSTALLATION.........................14
ENGINE COOLANT TEMP SENSOR
DESCRIPTION.........................14REMOVAL.............................14
INSTALLATION.........................15
ENGINE COOLANT THERMOSTAT
REMOVAL.............................15
INSTALLATION.........................16
FAN DRIVE VISCOUS CLUTCH
REMOVAL.............................16
INSTALLATION.........................16
RADIATOR
REMOVAL.............................16
INSTALLATION.........................17
RADIATOR PRESSURE CAP
DESCRIPTION.........................18
OPERATION...........................18
DIAGNOSIS AND TESTING - RADIATOR
PRESSURE CAP......................19
WATER PUMP
REMOVAL.............................19
INSTALLATION.........................20
COOLANT
DESCRIPTION
Coolant flows through the engine water jackets and
cylinder heads absorbing heat produced by the engine
during operation. The coolant carries heat to the radia-
tor and heater core. Here it is transferred to ambient
air passing through the radiator and heater core fins.
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. Also, a higher percentage of antifreeze can
cause the engine to overheat because the specific
heat of antifreeze is lower than that of water.100 Percent Ethylene-GlycolÐShould Not Be Used in
Chrysler Vehicles
Use of 100 percent ethylene-glycol will cause forma-
tion of additive deposits in the system, as the corrosion
inhibitive additives in ethylene-glycol require the pres-
ence 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 detonation. 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 ethylene-
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 (protec-
tion 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-glycol. Use of pro-
pylene-glycol can result in boil-over or freeze-up in
Chrysler vehicles, which are designed for ethylene-gly-
col. Propylene glycol also has poorer heat transfer char-
VAENGINE 7 - 9

acteristics than ethylene glycol. This can increase
cylinder head temperatures under certain 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.
DIAGNOSIS AND TESTING - COOLING SYSTEM
LEAKS
ULTRAVIOLET LIGHT METHOD
A leak detection additive is available through the
parts department that can be added to cooling sys-
tem. The additive is highly visible under ultraviolet
light (black light). Pour one ounce of additive into
cooling system. Place heater control unit in HEAT
position. Start and operate engine until radiator
upper hose is warm to touch. Aim the commercially
available black light tool at components to be
checked. If leaks are present, black light will cause
additive to glow a bright green color.
The black light can be used in conjunction with a
pressure tester to determine if any external leaks
exist (Fig. 1).
PRESSURE TESTER METHOD
The engine should be at normal operating temper-
ature. Recheck the system cold if cause of coolant
loss is not located during the warm engine examina-
tion.
WARNING: HOT, PRESSURIZED COOLANT CAN
CAUSE INJURY BY SCALDING.
Carefully remove coolant recovery pressure con-
tainer cap and check coolant level. Push down on cap
to disengage it from stop tabs. Wipe inside of con-
tainer and examine lower inside sealing seat for
nicks, cracks, paint, dirt and solder residue. Inspect
radiator-to- pressure container hose for internal
obstructions. Insert a wire through the hose to be
sure it is not obstructed.Inspect cams on outside of pressure container. If
cams are damaged, seating of pressure cap valve and
tester seal will be affected.
Attach pressure tester (7700 or an equivalent) to
coolant pressure container (Fig. 2).
Fig. 1 Leak Detection Using Black Light - Typical
1 - TYPICAL BLACK LIGHT TOOL
Fig. 2 PRESSURE TESTING
1 - PRESSURE RESERVOIR CAP
2 - PRESSURE RESERVOIR
3 - PRESSURE TESTER
7 - 10 ENGINEVA
COOLANT (Continued)

Operate tester pump to apply 103.4 kPa (15 psi)
pressure to system. If hoses enlarge excessively or
bulges while testing, replace as necessary. Observe
gauge pointer and determine condition of cooling sys-
tem according to following criteria:
Holds Steady:If pointer remains steady for two
minutes, serious coolant leaks are not present in sys-
tem. However, there could be an internal leak that
does not appear with normal system test pressure. If
it is certain that coolant is being lost and leaks can-
not be detected, inspect for interior leakage or per-
form Internal Leakage Test.
Drops Slowly:Indicates a small leak or seepage
is occurring. Examine all connections for seepage or
slight leakage with a flashlight. Inspect radiator,
hoses, gasket edges and heater. Seal small leak holes
with a Sealer Lubricant (or equivalent). Repair leak
holes and inspect system again with pressure
applied.
Drops Quickly:Indicates that serious leakage is
occurring. Examine system for external leakage. If
leaks are not visible, inspect for internal leakage.
Large radiator leak holes should be repaired by a
reputable radiator repair shop.
INTERNAL LEAKAGE INSPECTION
Remove engine oil pan drain plug and drain a
small amount of engine oil. If coolant is present in
the pan, it will drain first because it is heavier than
oil. An alternative method is to operate engine for a
short period to churn the oil. After this is done,
remove engine dipstick and inspect for water glob-
ules. Also inspect transmission dipstick for water
globules and transmission fluid cooler for leakage.
WARNING: WITH RADIATOR PRESSURE TESTER
TOOL INSTALLED ON RADIATOR, DO NOT ALLOW
PRESSURE TO EXCEED 110 KPA (20 PSI). PRES-
SURE WILL BUILD UP QUICKLY IF A COMBUSTION
LEAK IS PRESENT. TO RELEASE PRESSURE,
ROCK TESTER FROM SIDE TO SIDE. WHEN
REMOVING TESTER, DO NOT TURN TESTER MORE
THAN 1/2 TURN IF SYSTEM IS UNDER PRESSURE.
Operate engine without pressure cap on coolant
container until thermostat opens. Attach a Pressure
Tester to container. If pressure builds up quickly it
indicates a combustion leak exists. This is usually
the result of a cylinder head gasket leak or crack in
engine. Repair as necessary.
If there is not an immediate pressure increase,
pump the Pressure Tester. Do this until indicated
pressure is within system range of 110 kPa (16 psi).
Fluctuation of gauge pointer indicates compression or
combustion leakage into cooling system.Because the vehicle is equipped with a catalytic
converter,do notremove spark plug cables or short
out cylinders to isolate compression leak.
If the needle on dial of pressure tester does not
fluctuate, race engine a few times to check for an
abnormal amount of coolant or steam. This would be
emitting from exhaust pipe. Coolant or steam from
exhaust pipe may indicate a faulty cylinder head gas-
ket, cracked engine cylinder block or cylinder head.
A convenient check for exhaust gas leakage into
cooling system is provided by a commercially avail-
able Block Leak Check tool. Follow manufacturers
instructions when using this product.
COMBUSTION LEAKAGE TEST - WITHOUT
PRESSURE TESTER
DO NOT WASTE reusable coolant. If solution is
clean, drain coolant into a clean and suitably marked
container for reuse.
WARNING: DO NOT REMOVE CYLINDER BLOCK
DRAIN PLUGS OR LOOSEN RADIATOR DRAIN
WITH SYSTEM HOT AND UNDER PRESSURE. SERI-
OUS BURNS FROM COOLANT CAN OCCUR.
Drain sufficient coolant to allow thermostat removal.
Remove accessory drive belt.
Add coolant to pressure container to bring level to
within 6.3 mm (1/4 in) of top of thermostat housing.
CAUTION: Avoid overheating. Do not operate
engine for an excessive period of time. Open drain-
cock immediately after test to eliminate boil over.
Start engine and accelerate rapidly three times, to
approximately 3000 rpm while observing coolant. If
internal engine combustion gases are leaking into
cooling system, bubbles will appear in coolant. If bub-
bles do not appear, internal combustion gas leakage
is not present.
STANDARD PROCEDURE
STANDARD PROCEDURE - ADDING
ADDITIONAL COOLANT
The use of aluminum cylinder blocks, cylinder
heads and water pumps requires special corrosion
protection. Only MopartAntifreeze/Coolant, 5
Year/100,000 Mile Formula (glycol base coolant with
corrosion inhibitors called HOAT, for Hybrid Organic
Additive Technology) is recommended. This coolant
offers the best engine cooling without corrosion when
mixed with 50% distilled water to obtain to obtain a
freeze point of -37ÉC (-35ÉF). If it loses color or
becomes contaminated, drain, flush, and replace with
fresh properly mixed coolant solution.
VAENGINE 7 - 11
COOLANT (Continued)

CAUTION: Do not use coolant additives that are
claimed to improve engine cooling.
STANDARD PROCEDURE - DRAINING COOLING
SYSTEM
WARNING: DO NOT REMOVE THE CYLINDER
BLOCK DRAIN PLUG OR LOOSEN THE RADIATOR
DRAIN PLUG WITH SYSTEM HOT AND UNDER
PRESSURE. SERIOUS BURNS FROM COOLANT
CAN OCCUR.
(1) DO NOT remove coolant recovery pressure con-
tainer cap first. With engine cold, raise vehicle on a
hoist and locate radiator draincock.
NOTE: Radiator draincock is located on the left/
lower side of radiator.
(2)
Attach one end of a hose to the draincock (Fig. 3).
Put the other end into a clean and appropriately
marked container. Open draincock and drain coolant
from radiator. This will empty the coolant recovery pres-
sure container first. The coolant does not have to be
removed from the container unless the system is being
refilled with a fresh mixture. When container is empty,
remove cap and continue draining cooling system.
To drain the engine of coolant, loosen the cylinder
block drain plug located on the side of cylinder block
(Fig. 3).
STANDARD PROCEDURE - REFILLING
COOLING SYSTEM
(1) Tighten the radiator drain and the cylinder
block drain plug(s) (if removed). Tighten the engine
drain plug to 22 lbs. ft. (30 N´m)
(2) Fill system using a 50/50 mixture of ethylene-
glycol antifreeze and low mineral content water. Fill
radiator to top and add sufficient coolant to the cool-
ant recovery pressure container to raise level to
COLD MINIMUM mark.
(3) With heater control unit in the HEAT position,
operate engine with container cap in place.
(4) After engine has reached normal operating
temperature, shut engine off and allow it to cool.
When engine is cooling down, coolant will be drawn
into the radiator from the pressure container.
(5) Add coolant to pressure container as necessary.
Only add coolant to the container when the
engine is cold. Coolant level in a warm engine
will be higher due to thermal expansion.To
purge the cooling system of all air, this heat up/cool
down cycle (adding coolant to cold engine) must be
performed three times. Add necessary coolant to raise
container level to the COLD MINIMUM mark after
each cool down period.
Fig. 3 DRAINING COOLANT SYSTEM
1 - DRAIN HOSE 3 - RADIATOR DRAIN PLUG
2 - ENGINE DRAIN PLUG 4 - DRAIN HOSE
7 - 12 ENGINEVA
COOLANT (Continued)

COOLANT LEVEL SENSOR
REMOVAL
WARNING: RISK OF INJURY TO SKIN AND EYES
DUE TO SCALDING FROM HOT COOLANT. DO NOT
OPEN THE COOLING SYSTEM UNLESS THE TEM-
PERATURE IS BELOW 194ÉF (90ÉC). WEAR PRO-
TECTIVE CLOTHING AND EYE WEAR. RISK OF
POISONING IF COOLANT IS SWALLOWED. STORE
COOLANT IN PROPER AND APPROPRIATELY
MARKED CONTAINERS.
NOTE: Drain coolant from radiator drain plug only.
(1) Drain coolant until the coolant reservoir is
emptied.
(2) Disconnect the wiring harness electrical con-
nector.
(3) Turn the level sensor 90 degrees clockwises, lift
up and out of the container.
INSTALLATION
(1) Align coolant level sensor with coolant
reservior access whole, press down while turning
counterclockwise 90 degrees to seat sensor (Fig. 4).
(2) Connect coolant level sensor electrical connec-
tor (Fig. 4).
(3) Refill cooling system to proper level.
(4) Inspect for leaks.
RADIATOR FAN
REMOVAL
(1) Disconnect the negative battery cable.
(2) Remove the front end cross member.
(3) Push complete radiator assembly forward and
unclip the fan shroud at the radiator.
(4) Detach coolant line from lower radiator shroud.
(5) Retain accessory drive belt pulley of water
pump with a counterholder (Fig. 5).
(6) Unscrew the central bolt of the viscous fan
clutch and lift fan and shroud up and out (Fig. 5).
NOTE: Store the viscous fan clutch in the upright
position. DO NOT place down flat.
(7) Remove radiator fan from viscous fan clutch
(Fig. 5).
INSTALLATION
(1) Install fan blade to viscous clutch. Tighten
bolts to 80 lbs. in. (9 N´m) (Fig. 5).
(2) Install fan and clutch along with fan shroud in
to engine bay area (Fig. 5).
(3) Install the center bolt of the viscous clutch.
Tighten bolt to 33 lbs. ft. (45 N´m) (Fig. 5)
(4) Attach coolant line to lower radiator shroud.
(5)
Properly align and clip the fan shroud into place.
Fig. 4 COOLANT LEVEL SENSOR
1 - COOLANT LEVEL SENSOR
2 - COOLANT RESERVIOR
3 - ELECTRICAL CONNECTOR
Fig. 5 RADIATOR FAN
1 - VISCOUS CLUTCH
2 - COUNTERHOLDER
3 - CLUTCH BOLT
4 - FAN BOLT
5-FAN
VAENGINE 7 - 13

(6) Properly align the radiator assembly and
install the front end cross member.
(7) Connect negative battery cable.
ENGINE BLOCK HEATER
REMOVAL
WARNING: RISK OF INJURY TO SKIN AND EYES
DUE TO SCALDING FROM HOT COOLANT. DO NOT
OPEN THE COOLING SYSTEM UNLESS THE TEM-
PERATURE IS BELOW 194ÉF (90ÉC). WEAR PRO-
TECTIVE CLOTHING AND EYE WEAR. RISK OF
POISONING IF COOLANT IS SWALLOWED. STORE
COOLANT IN PROPER AND APPROPRIATELY
MARKED CONTAINERS.
(1) Disconnect the negative battery cable.
(2) Drain the cooling system.
(3) Record the location and snip the wire ties.
(4) Unscrew the engine block heater from the core
plug hole and remove (Fig. 6).
INSTALLATION
(1) Screw the block heater into the appropriate
core hole (Fig. 6).
(2) Route the heater wiring harness away from
and interference and secure with wiring tie straps.
(3) Refill the cooling system.
(4) Connect the negative battery cable.
(5) Start the engine and inspect for leaks.
ENGINE COOLANT TEMP
SENSOR
DESCRIPTION
The ECM determines the operating temperature of
the engine by using the signal from the coolant tem-
perature sensor. The coolant temperature sensor has
a negative temperature coefficient (NTC) resistor
contained in the plastic housing. NTC means; the
higher the temperature, then the lower the resis-
tance. The ECM also uses the coolant temperature
sensor signal to calculate glow plug relay triggering.
If the coolant temperature sensor fails during opera-
tion, the ECM will switch on the cooling fan to pre-
vent engine overheating (A/C models only).
REMOVAL
WARNING: RISK OF INJURY TO SKIN AND EYES
FROM SCALDING WITH HOT COOLANT. RISK OF
POISONING FROM SWALLOWING COOLANT. DO
NOT OPEN COOLING SYSTEM UNLESS COOLANT
TEMPERATURE IS BELOW 90ÉC. OPEN CAP
SLOWLY TO RELEASE PRESSURE. STORE COOL-
ANT IN SUITABLE AND APPROPRIATELY MARKED
CONTAINER. WEAR PROTECTIVE GLOVES,
CLOTHES AND EYE WEAR.
(1) Disconnect negative battery cable.
(2) Remove engine cover (Refer to 9 - ENGINE -
REMOVAL).
(3) Partailly drain coolant system (Refer to 7 -
COOLING/ENGINE/COOLANT - STANDARD PRO-
CEDURE).
(4) Unplug coolant temperature sensor electrical
connector.
Fig. 6 ENGINE BLOCK HEATER
1 - ENGINE BLOCK HEATER
2 - CORE PLUG
3 - ENGINE MOUNT
4 - WIRING TIE STRAPS
7 - 14 ENGINEVA
RADIATOR FAN (Continued)