
COOLING SYSTEM DIAGNOSIS-DIESEL ENGINE
CONDITION POSSIBLE CAUSES CORRECTION
TEMPERATURE GAUGE
READS LOW1. Diesel engines, due to their
inherent effiency are slower to warm
up than gasoline powered engines,
and will operate at lower
temperatures when the vehicle is
unloaded.1. The low gauge reading may
be normal. Refer to thermostats
in the manual text for
information. See Thermostat
Diagnosis-Diesel Engine.
2. Is the temperature gauge
connected to the temperature gauge
coolant sensor on the engine?2. Check, the engine
temperature sensor connector
in the engine compartment.
3. Is the temperature gauge
operating OK?3. Check gauge operation.
Repair as necessary.
4. Coolant level low in cold ambient
temperatures accompanied with poor
heater performance.4. Check coolant level in the
coolant tank. Inspect system for
leaks. Repair leaks as
necessary. Refer to the Coolant
section for WARNINGS and
precautions before removing
the pressure cap.
5. Improper operation of internal
heater doors or heater controls.5. Inspect heater and repair as
necessary. Refer to Heating
and Air Conditioning for
procedures.
TEMPERATURE GAUGE
READS HIGH. COOLANT
MAY OR MAY NOT BE
LOST OR LEAKING FROM
COOLING SYSTEM1. Trailer is being towed, a steep hill
is being climbed, vehicle is operated
in slow moving traffic, or engine is
being idled with very high ambient
(outside) temperature and the air
conditioning is on. Higher altitudes
could aggravate these conditions.1. This may be a temporary
condition and repair is not
necessary. Turn off the air
conditioning and attempt to
drive the vehicle without any of
the previous conditions.
Observe the temperature
gauge. The gauge should return
to the normal range. If the
gauge does not return to
normal range, determine the
cause for the overheating and
repair.
2. Temperature gauge reading
incorrectly.2. Check gauge. Refer to I/P
group.
3. Coolant low in coolant tank and
radiator.3. Check for coolant leaks and
repair as necessary.
4. Pressure cap not installed tightly.
If cap is loose, boiling point of
coolant will be lowered.4. Tighten cap.
5. Poor seals at pressure/vent cap. 5. (a) Check condition of cap
and cap seals. (b) Check
condition of coolant tank filler
neck. Make sure it does not
leak pressure.
7a - 2 COOLING 2.5L TURBO DIESELRG
COOLING 2.5L TURBO DIESEL (Continued)

CONDITION POSSIBLE CAUSES CORRECTION
INADEQUATE AIR
CONDITIONER
PERFORMANCE
(COOLING SYSTEM
SUSPECTED)1. Radiator and/or A/C condensor is
restricted, obstructed or dirty
(insects, leaves, etc.)1. Remove restriction or clean
debris from radiator or A/C
condensor.
2. Engine is overheating (heat may
be transferred from radiator to A/C
condensor. High underhood
temperatures due to engine
overheating may also transfer heat
to A/C condensor).2. Correct overheating
condition.
3. The cooling system is equipped
with air seals at the radiator and/or
A/C condensor. If these seals are
missing or damaged, not enough air
flow will be pulled through the
radiator and A/C condensor.3. Check for missing or
damaged air seals. Repair as
necessary.
INADEQUATE HEATER
PERFORMANCE. MAY BE
ACCOMPANIED BY LOW
GAUGE READING1. Diesel engines, due to their
inherent efficiency are slower to
warm up than gasoline powered
engines, and will operate at lower
temperatures when the vehicle is
unloaded.1. The lower gauge reading
may be normal.
2. Coolant level low. 2. Pressure test cooling system.
Repair leaks as necessary.
3. Obstruction in heater hose fitting
at engine.3. Remove heater hoses and
check for obstructions. Repair
as necessary.
4. Heater hose kinked. 4. Locate kinked area. Repair
as necessary.
5. Water pump is not pumping water
to heater core. When the engine is
fully warmed up, both heater hoses
should be hot to the touch. If only
one of the hoses is hot the water
pump may not be operating correctly.
The accessory drive belt may also
be slipping causing poor water pump
operation.5. Refer to water pumps in this
group. Repair as necessary. If a
slipping belt is detected, refer to
Engine Accessory Drive Belts in
this group. Repair as
necessary.
HEAT ODOR 1. Various heat shields are used at
certain drive line components. One
or more of these shields may be
missing.1. Locate missing shields.
Repair or replace as necessary.
2. Is temerature gauge reading
above the normal range?2. Refer to the previous
Temperature Gauge Reads
High in these Diagnostic
Charts. Repair as necessary.
3. Is the Cooling fan operating
correctly?3. Refer to Cooling System Fan
in this group for diagnosis.
Repair as necessary.
RGCOOLING 2.5L TURBO DIESEL7a-5
COOLING 2.5L TURBO DIESEL (Continued)

ENGINE
TABLE OF CONTENTS
page page
COOLANT
DESCRIPTION...........................14
DIAGNOSIS AND TESTING.................15
COOLANT CONCENTRATION TESTING......15
STANDARD PROCEDURE..................15
COOLANT SERVICE.....................15
ADDING ADDITIONAL COOLANT...........15
COOLANT LEVEL CHECK................16
REFILLING COOLING SYSTEM............16
DRAINING COOLING SYSTEM.............16
COOLANT RECOVERY PRESS CONTAINER
DESCRIPTION...........................17
OPERATION.............................17
REMOVAL..............................18
INSTALLATION...........................18
ENGINE COOLANT TEMP SENSOR
DESCRIPTION...........................19
OPERATION.............................19
REMOVAL..............................19
INSTALLATION...........................19
ENGINE COOLANT THERMOSTAT
DESCRIPTION...........................19
OPERATION.............................19
REMOVAL..............................19
INSTALLATION...........................20
RADIATOR
DESCRIPTION...........................20
OPERATION.............................20
REMOVAL..............................20
INSTALLATION...........................21
RADIATOR DRAINCOCK
REMOVAL..............................22INSTALLATION...........................22
WATER PUMP
DESCRIPTION...........................22
OPERATION.............................22
REMOVAL..............................22
CLEANING..............................23
INSTALLATION...........................23
RADIATOR PRESSURE CAP
DESCRIPTION...........................24
OPERATION.............................24
DIAGNOSIS AND TESTING.................25
COOLING SYSTEM PRESSURE CAP........25
PRESSURE RELIEF TEST................25
CLEANING..............................25
INSPECTION............................26
RADIATOR FAN
DESCRIPTION...........................26
OPERATION.............................26
DIAGNOSIS AND TESTING.................26
RADIATOR FAN MOTOR.................26
REMOVAL..............................27
INSTALLATION...........................27
HOSE CLAMPS
DESCRIPTION...........................27
OPERATION.............................28
RADIATOR FAN RELAY
DESCRIPTION...........................28
OPERATION.............................28
COOLANT SYSTEM HOSES
REMOVAL..............................28
INSTALLATION...........................29
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 radiator 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 protectionagainst 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.
7a - 14 ENGINERG

RADIATOR PRESSURE CAP
DESCRIPTION
The cooling system pressure cap is located on the
radiator. The cap construction includes; stainless
steel swivel top, rubber seals, and retainer, main
spring, and a spring loaded valve (Fig. 19).
OPERATION
The cooling system is equipped with a pressure cap
that releases excessive pressure; maintaining a range
of 97-124 kPa (14-18 psi).
The cooling system will operate at higher than
atmospheric pressure. The higher pressure raises the
coolant boiling point thus, allowing increased radia-
tor cooling capacity.
There is also a vent valve in the center of the cap.
This valve also opens when coolant is cooling and
contracting, allowing the coolant to return to cooling
system from coolant reserve system tank by vacuum
through a connecting hose.If valve is stuck shut,
or the coolant recovery hose is pinched, the
radiator hoses will be collapsed on cool down.
Clean the vent valve (Fig. 19) and inspect cool-
ant recovery hose routing, to ensure proper
sealing when boiling point is reached.
The gasket in the cap seals the filler neck, so that
vacuum can be maintained, allowing coolant to be
drawn back into the radiator from the reserve tank.
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.
Fig. 17 WATER PUMP ASSEMBLY
1 - WATER PUMP HOUSING STUDS
2 - WATER PUMP
3 - RETAINING NUTS
4 - OIL COOLER RETAINING STUD
5 - OIL COOLER TO ENGINE BLOCK RETAINING BOLT
6 - OIL COOLER COOLANT HOSE
7 - ENGINE BLOCK
Fig. 18 WATER PUMP HOUSING O-RING
1 - WATER PUMP
2 - WATER PUMP HOUSING O-RING
3 - WATER PUMP HOUSING
Fig. 19 Cooling System Pressure Cap Filler Neck
1 - OVERFLOW NIPPLE
2 - MAIN SPRING
3 - GASKET RETAINER
4 - STAINLESS-STEEL SWIVEL TOP
5 - RUBBER SEALS
6 - VENT VALVE
7 - PRESSURE BOTTLE
8 - FILLER NECK
7a - 24 ENGINERG
WATER PUMP (Continued)

FASTEN SEAT BELT LAMP OR TONE CONTINUES
FOR MORE THAN 10 SECONDS AFTER SEAT
BELTS ARE FASTENED AND DRIVER'S DOOR IS
CLOSED.
Refer to the proper Body Diagnostic Procedures
manual.
NO TONE WHEN PARK OR HEADLAMPS ARE ON
AND DRIVER'S DOOR IS OPEN.
Make sure ignition is in lock position with the key
removed.
(1) Check the BCM DTC's and BCM sensors to
verify the door is open. Repair as necessary.
(2) Actuate Chime (BCM actuates).
(3) Inspect BCM connectors and wires for proper
connection.
(4) Measure with a voltmeter the voltage (12v) on
BCM connector (PX2) pin 34 with harness connected.
DIAGNOSIS AND TESTING - DOME LAMP ON
CHIME
The dome lamp on chime will warn the driver that
the dome lamps have been left on.
When the ignition is OFF:
²Driver's door OPEN (door ajar switch is closed to
ground) and
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. Chime rate: 168 to 192 chimes per minute.
DIAGNOSIS AND TESTING - 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 PCI
data bus as engine temperature every 1.376 seconds
to the cluster. The MIC calculates engine tempera-
ture 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 MIC requests a chime from the BCM and
the engine temperature lamp comes ON. The MIC
turns OFF the lamp when the engine temperature
reaches 117ÉC (242ÉF). The MIC will chime continu-
ously (request from the BCM). The chime will turn
OFF after four minutes or when the temperature
reaches 117ÉC (242ÉF), which ever occurs first.
DIAGNOSIS AND TESTING - 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/key out of ignition:
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.
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.
DIAGNOSIS AND TESTING - 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 (ignition is in the
LOCK position)
The chime will sound until one of the above condi-
tions is removed or until battery protection time out
(15 min.) has expired. 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.
For diagnosis and testing of the Key-In Accessory
chime, use the same testing procedure as above but
with the key in the accessory position.
DIAGNOSIS AND TESTING - LOW OIL
PRESSURE CHIME
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 PCM will monitor the oil
pressure switch and signal a low oil pressure condi-
tion. A continuous four minute warning chime will
sound and the oil pressure lamp will come ON when
the following conditions are met:
²Ignition on and engine not cranking
8B - 2 CHIME/BUZZERRS
CHIME/BUZZER (Continued)

(M) Check Engine Lamp (MIL) will illuminate during engine operation if this Diagnostic Trouble Code was recorded.
(G) Generator Lamp Illuminated
GENERIC SCAN
TOOL CODEDRB SCAN TOOL DISPLAY DESCRIPTION OF DIAGNOSTIC TROUBLE CODE
P1292 CNG Pressure Sensor Voltage Too
HighCompressed natural gas pressure sensor reading above
acceptable voltage.
P1293 CNG Pressure Sensor Voltage Too
LowCompressed natural gas pressure sensor reading below
acceptable voltage.
P1294 (M) Target Idle Not Reached Target RPM not achieved during drive idle condition.
Possible vacuum leak or IAC (AIS) lost steps.
P1295 No 5 Volts to TP Sensor Loss of a 5 volt feed to the Throttle Position Sensor has
been detected.
P1296 No 5 Volts to MAP Sensor Loss of a 5 volt feed to the MAP Sensor has been detected.
P1297 (M) No Change in MAP From Start To
RunNo difference is recognized between the MAP reading at
engine idle and the stored barometric pressure reading.
P1298 Lean Operation at Wide Open
ThrottleA prolonged lean condition is detected during Wide Open
Throttle.
P1299 (M) Vacuum Leak Found (IAC Fully
Seated)MAP Sensor signal does not correlate to Throttle Position
Sensor signal. Possible vacuum leak.
P1388 Auto Shutdown Relay Control Circuit An open or shorted condition detected in the ASD or CNG
shutoff relay control ckt.
P1389 No ASD Relay Output Voltage At
PCMNo Z1 or Z2 voltage sensed when the auto shutdown relay
is energized.
P1390 (M) Timing Belt Skipped 1 Tooth or More Relationship between Cam and Crank signals not correct.
P1391 (M) Intermittent Loss of CMP or CKP Loss of the Cam Position Sensor or Crank Position sensor
has occurred. For PL 2.0L
P1398 (M) Mis-Fire Adaptive Numerator at Limit PCM is unable to learn the Crank Sensor's signal in
preparation for Misfire Diagnostics. Probable defective Crank
Sensor.
P1399 Wait To Start Lamp Cicuit An open or shorted condition detected in the Wait to Start
Lamp circuit.
P1403 No 5 Volts to EGR Sensor Loss of 5v feed to the EGR position sensor.
P1476 Too Little Secondary Air Insufficient flow of secondary air injection detected during
aspirator test.(was P0411)
P1477 Too Much Secondary Air Excessive flow of secondary air injection detected during
aspirator test (was P0411).
P1478 (M) Battery Temp Sensor Volts Out of
LimitInternal temperature sensor input voltage out of an
acceptable range.
P1479 Transmission Fan Relay Circuit An open or shorted condition detected in the transmission
fan relay circuit.
P1480 PCV Solenoid Circuit An open or shorted condition detected in the PCV solenoid
circuit.
P1482 Catalyst Temperature Sensor Circuit
Shorted LowCatalyst temperature sensor circuit shorted low.
P1483 Catalyst Temperature Sensor Circuit
Shorted High.Catalyst temperature sensor circuit shorted high.
P1484 Catalytic Converter Overheat
DetectedA catalyst overheat condition has been detected by the
catalyst temperature sensor.
8E - 16 ELECTRONIC CONTROL MODULESRS
POWERTRAIN CONTROL MODULE (Continued)

Schedule Condition Expected Operation
HotOil temperature at start-up above
80É F± Normal operation (upshift,
kickdowns, and coastdowns)
± Full EMCC, no PEMCC except to
engage FEMCC (except at closed
throttle at speeds above 70-83 mph)
OverheatOil temperature above 240É F or
engine coolant temperature above
244É F± Delayed 2-3 upshift (25-32 mph)
± Delayed 3-4 upshift (41-48 mph)
± 3rd gear FEMCC from 30-48 mph
± 3rd gear PEMCC from 27-31 mph
Super OverheatOil temperature above 260É F ± All9Overheat9shift schedule
features apply
± 2nd gear PEMCC above 22 mph
± Above 22 mph the torque
converter will not unlock unless the
throttle is closed or if a wide open
throttle 2nd PEMCC to 1 kickdown
is made
STANDARD PROCEDURE - PINION FACTOR
SETTING
NOTE: This procedure must be performed if the
Transmission Control Module (TCM) has been
replaced with a NEW or replacement unit. Failure to
perform this procedure will result in an inoperative
or improperly calibrated speedometer.
The vehicle speed readings for the speedometer are
taken from the output speed sensor. The TCM must
be calibrated to the different combinations of equip-
ment (final drive and tires) available. Pinion Factor
allows the technician to set the Transmission Control
Module initial setting so that the speedometer read-
ings will be correct. To properly read and/or reset the
Pinion Factor, it is necessary to use a DRB scan tool.
(1) Plug the DRB scan tool into the diagnostic con-
nector located under the instrument panel.
(2) Select the Transmission menu.
(3) Select the Miscellaneous menu.
(4) Select Pinion Factor. Then follow the instruc-
tions on the DRB scan tool screen.
STANDARD PROCEDURE - QUICK LEARN
PROCEDURE
The quick learn procedure requires the use of the
DRB scan tool. This program allows the electronic
transaxle system to recalibrate itself. This will pro-
vide the best possible transaxle operation.NOTE: The quick learn procedure should be per-
formed if any of the following procedures are per-
formed:
²Transaxle Assembly Replacement
²Transmission Control Module Replacement
²Solenoid/Pressure Switch Assembly Replacement
²Clutch Plate and/or Seal Replacement
²Valve Body Replacement or Recondition
To perform the Quick Learn Procedure, the follow-
ing conditions must be met:
²The brakes must be applied
²The engine speed must be above 500 rpm
²The throttle angle (TPS) must be less than 3
degrees
²The shift lever position must stay until
prompted to shift to overdrive
²The shift lever position must stay in overdrive
after the Shift to Overdrive prompt until the DRB
indicates the procedure is complete
²The calculated oil temperature must be above
60É and below 200É
(1) Plug the DRB scan tool into the diagnostic con-
nector. The connector is located under the instrument
panel.
(2) Go to the Transmission screen.
(3) Go to the Miscellaneous screen.
(4) Select Quick Learn Procedure. Follow the
instructions of the DRB to perform the Quick Learn
Procedure.
RSELECTRONIC CONTROL MODULES8E-27
TRANSMISSION CONTROL MODULE (Continued)

(1) Check battery before performing this test. Bat-
tery must be fully charged.
(2) Connect a volt-ampere tester to the battery ter-
minals. Refer to the operating instructions provided
with the tester being used.
(3) 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.
(4) Verify that all lights and accessories are OFF,
and the transmission shift selector is in the PARK
and SET parking brake.
CAUTION: Do not overheat the starter motor or
draw the battery voltage below 9.6 volts during
cranking operations.
(5) Rotate and hold the ignition switch in the
START position. Observe the volt-ampere tester (Fig.
2).
²If voltage reads above 9.6 volts, and amperage
draw reads above 280 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, the problem is the starter. Replace
the starter refer to starter removal.
(6) 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. Start the vehicle
several times to assure the problem has been cor-
rected.
SPECIFICATIONS
STARTER
MANUFACTURER NIPPONDENSO
Engine Application 2.4L /3.3/3.8L
Power rating 1.2 Kw
Voltage 12 VOLTS
No. of Fields 4
No. of Poles 4
Brushes 4
Drive Conventional Gear Train
Free running Test
Voltage 11
Amperage Draw 73 Amp
Minimum Speed 3401 RPM
SolenoidClosing Voltage 7.5 Volts
Cranking Amperage Draw
test150 - 200 Amps.
Engine should be up to operating temperature.
Extremely heavy oil or tight engine will increase
starter amperage draw.
Torques
DESCRIPTION N´m Ft. Lbs. In. Lbs.
Starter Mounting Bolts 47.4 35
Starter Solenoid Battery
Nut11.3 8.3 100
8F - 32 STARTINGRS
STARTING (Continued)