CONDITION - AND CHECKS DIAGNOSIS
Inadequate Air Conditioning Performance - Cooling System Suspected
(1) Check for plugged air side of condenser and
radiator front and rear.(1) Wash out with low-velocity water.
(2) Assure fan runs whenever A/C head pressure
exceeds 1724 kPa (250 psi).(2) Repair as necessary.
(3) Check for missing air seals-recirculating air path.
(4) Assure correct cooling system parts.
Battery Dead - Suspect Fan Current Draw as Cause
(1) With a good, fully charged battery. (1) a - Assure fan control is operating properly.
(1) b - See charging system in Electrical, Group 8B.
Hot Smell - Suspect Cooling System
(1) Was temperature gauge high? (1) a - Yes, See9Gauge Reads High9
(1) b - No. See 2, 3, 4, and 5.
(2) Heat shields all in place? (2) a - Yes, See 3, 4, and 5.
(2) b - Repair or replace heat shields.
(3) Fan control operating properly? (3) a - Yes, See 4 and 5.
(3) b - No, See Radiator Fan Control this section.
(4) Heat exchanger air side plugged? (4) Clean as required.
(5) Engine missing or running rich? (5) Repair as required.
Poor Driveability - Suspect Failed Open Thermostat.
(1) Check diagnostics - is code 17 set? (Engine too
cold for too long)(1) If yes, change thermostat.
Poor Heater Performance - Suspect Failed Open Thermostat
(1) Does gauge read low? (1) See 3
(2) Check coolant level. (2) See 3
(3) Check diagnostics - is code 17 set? (Engine too
cold for too long)(3) If yes, change thermostat. If no, check heater
bypass valve, which should be closed except in Max
A/C or off mode; if not, see Heater and Air Conditioning
Group, 24.
Steaming, Observe Water Vapor Through Grill or Head Gap at Standstill at Idle - In Wet Weather
(1) This is normal. It is moisture, snow, or water on the
outside of the radiator that evaporates when the
thermostat opens to put hot coolant into the radiator.
This usually occurs in cold weather with no fan or air
flow to blow it away.(1) Normal condition - no service required.
NSCOOLING SYSTEM 7 - 13
DIAGNOSIS AND TESTING (Continued)
use. Refer to Causes of Battery Discharging in this
Group for more information.
NOTE: CLEAR COLOR = Replace Battery
WARNING: DO NOT CHARGE, ASSIST BOOST,
LOAD TEST, OR ADD WATER TO THE BATTERY
WHEN CLEAR COLOR DOT IS VISIBLE. PERSONAL
INJURY MAY OCCUR.
A clear color dot shows electrolyte level in battery
is below the test indicator (Fig. 1). Water cannot be
added to a maintenance free battery. The battery
must be replaced. A low electrolyte level may be
caused by an over charging condition. Refer to Gen-
erator Test Procedures on Vehicle.
CAUSES OF BATTERY DISCHARGING
It is normal to have a small 5 to 25 milliamperes
continuous electrical draw from the battery. This
draw will take place with the ignition in the OFF
position, and the courtesy, dome, storage compart-
ments, and engine compartment lights OFF. The con-
tinuous draw is due to various electronic features or
accessories that require electrical current with the
ignition OFF to function properly. When a vehicle is
not used over an extended period of approximately 20
days the IOD fuse should be pulled. The fuse is
located in the power distribution center. Disconnec-
tion of this fuse will reduce the level of battery dis-
charge. Refer to Battery Diagnosis and Testing table
and to the proper procedures.
ABNORMAL BATTERY DISCHARGING
²Corroded battery posts, cables or terminals.
²Loose or worn generator drive belt.
²Electrical loads that exceed the output of the
charging system due to equipment or accessories
installed after delivery.
²Slow driving speeds in heavy traffic conditions
or prolonged idling with high-amperage electrical
systems in use.²Defective electrical circuit or component causing
excess Ignition Off Draw (IOD). Refer to Battery
Ignition Off Draw (IOD).
²Defective charging system.
²Defective battery.
BATTERY IGNITION OFF DRAW (IOD)
High current draw on the battery with the ignition
OFF will discharge a battery. After a dead battery is
serviced the vehicle Ignition Off Draw (IOD) should
be checked. Determine if a high current draw condi-
tion exists first check the vehicle with a test lamp.
(1) Verify that all electrical accessories are OFF.
²Remove key from ignition switch
²Turn off all lights
²Liftgate and glove box door is closed
²Sun visor vanity lights are OFF
²All doors are closed
²Allow the Illuminated Entry System to time out
in approximately 30 seconds, if equipped.
²During Transmission Control Module (TCM)
power down there will be 500 milliamperes present
for 20 minutes. Afterwards less than 1.0 milliampere.
(2) Disconnect battery negative cable (Fig. 4).
CAUTION: Always disconnect the meter before
opening a door.
(3) Using an multimeter, that has least a milliam-
pere range of 200 mA. Set meter to the highest mA
range. Install meter between the battery negative
cable and battery negative post (Fig. 5). Carefully
remove the test lamp without disconnecting the
meter. After all modules time-out the total vehicle
IOD should be less than 25 milliamperes. If ignition
off draw is more than 25 milliamperes go to Step 4.
(4) Each time the test lamp or milliampere meter
is disconnected and connected, all electronic timer
functions will be activated for approximately one
minute. The Body Control Module (BCM) ignition off
draw can reach 90 milliamperes.
(5) Remove the PDC fuses:
²Interior lamps
²Brake lamp
²IOD
(6) If there is any reading, with fuses removed
there is a short circuit in the wiring. Refer to Group
8W, wiring diagrams. If reading is less than 25 mA
go to Step 8.
(7) Install all fuses. After installing fuse, the cur-
rent can reach 90 mA. After time-out the reading
should not exceed 25 mA. If OK go to. If not, discon-
nect:
²Radio
²Body Control Module
²Remote Keyless Entry Module
Fig. 3 Test Indicator
NSBATTERY 8A - 3
DIAGNOSIS AND TESTING (Continued)
hydrometer reading. Always correct the specific grav-
ity for temperature variation. Test the specific grav-
ity of the electrolyte in each battery cell. Refer to the
information with the Hydrometer.
Example 1:
²Hydrometer reading: 1.260
²Electrolyte temperature: -7ÉC (20ÉF)
²Subtract specific gravity: -0.019
²Correction specific gravity: 1.241
Example 2:
²Hydrometer reading: 1.225
²Electrolyte temperature: -38ÉC (100ÉF)
²Add specific gravity: +0.013
²Correction specific gravity: 1.238
A fully charged relatively new battery has a spe-
cific gravity reading of 1.285 plus 0.015 or minus
0.010.
If the specific gravity of all cells is above 1.235, but
variation between cells is more than 50 points
(0.050), it is an indication that the battery is unser-
viceable.
If the specific gravity of one or more cells is less
than 1.235, recharge the battery at a rate of approx-
imately 5 amperes. Continue charging until three
consecutive specific gravity tests, taken at one-hour
intervals, are constant.
If the cell specific gravity variation is more than 50
points (0.050) at the end of the charge period, replace
the battery.When the specific gravity of all cells is above 1.235
and variation between cells is less than 50 points
(0.050), the battery may be tested under heavy load.
DIAGNOSIS AND TESTING
BATTERY DISCHARGING
CAUSE OF BATTERY DISCHARGING
It is normal to have a small 5 to 25 milliamperes
continuous electrical draw from the battery. This
draw will take place with the ignition in the OFF
position, and the courtesy, dome, storage compart-
ments, and engine compartment lights OFF. The con-
tinuous draw is due to various electronic features or
accessories that require electrical current with the
ignition OFF to function properly. When a vehicle is
not used over an extended period of approximately 20
days the IOD fuse should be disconnected. The fuse
is located in the power distribution center. Disconnec-
tion of this fuse will reduce the level of battery dis-
charge. Refer to Battery Diagnosis and Testing Chart
and to the proper procedures.
ABNORMAL BATTERY DISCHARGING
²Corroded battery posts, cables or terminals.
²Loose or worn generator drive belt.
²Electrical loads that exceed the output of the
charging system due to equipment or accessories
installed after delivery.
²Slow driving speeds in heavy traffic conditions
or prolonged idling with high-amperage electrical
systems in use.
²Defective electrical circuit or component causing
excess Ignition Off Draw (IOD). Refer to Battery
Ignition Off Draw (IOD).
²Defective charging system.
²Defective battery.
BATTERY IGNITION OFF DRAW
High current draw on the battery with the ignition
OFF will discharge a battery. After a dead battery is
serviced the vehicle Ignition Off Draw (IOD) should
be checked. Determine if a high current draw condi-
tion exists first check the vehicle with a test lamp.
(1) Verify that all electrical accessories are OFF.
²Remove key from ignition switch
²Turn off all lights
²Liftgate and glove box door is closed
²Sun visor vanity lights are OFF
²All doors are closed
²Allow the Illuminated Entry System to time out
in approximately 30 seconds, if equipped.
(2) Disconnect battery negative cable (Fig. 4).
Fig. 3 Battery Hydrometer
NS/GSBATTERY 8A - 3
DESCRIPTION AND OPERATION (Continued)
²Stores transmitter data in permanent memory -
retraining is not required even if the battery dies or
is disconnected.
To operate, simply press the appropriate button on
the Universal Transmitter. The red LED will light up
while the signal is being transmitted.
NOTE: For security reasons, you are able to erase
the trained frequencies.
DIAGNOSIS AND TESTING
READING/DOME LAMP DIAGNOSIS
The dome lamps operate in conjunction with the
Remote Keyless Entry system. Refer to the Wiring
Diagrams group of this manual for component loca-
tions and circuit information. For additional diagnos-
tic information on lamp operation controlled by Body
Control Module (BCM) refer to the Body Diagnostic
Procedures Manual. For diagnosis of the reading
lamps and switches refer to (Fig. 3).
TRAVELER MESSAGES
Traveler data is obtained from the Body Control
Module (BCM) on the CCD bus wires. The CMTC
will not display information for any of the screens forwhich it did not receive the bus messages. The label
corresponding to the missing information will be lit.
If no traveler data is displayed, check the CCD com-
munications and the BCM. If the brightness level is
improper check the CCD bus. One general method
for checking the CCD bus communications between
CMTC and the BCM is refer to the following proce-
dure.
(1) STEP the CMTC to the Elapsed Time (ET).
(2) Press and release the reset button to reset the
module.
(3) If the elapsed time clock does not reset, or fails
to update, check the CCD wires and the BCM. The
DRB is recommended for checking the CCD and the
BCM.
(4) Perform the CMTC self diagnosis before replac-
ing the module.
UNIVERSAL TRANSMITTER
Before proceeding in diagnosis, check the transmit-
ter for battery voltage and a good ground at the
transmitter harness connector.
²The unit may not have been trained correctly,
try retraining the transmitter.
²The batteries in the hand-held transmitter may
be dead.
Fig. 3 Reading/Dome Lamp Diagnosis
NSOVERHEAD CONSOLE 8V - 3
DESCRIPTION AND OPERATION (Continued)
(4) Remove upper intake manifold. Refer to Group
11, Exhaust System and Intake Manifolds for proce-
dure.
(5) Remove cylinder head covers and spark plugs.
(6) Remove electrical connector from ignition coils.
(7) Using suitable socket and flex handle at crank-
shaft pulley retaining screw, turn engine so the num-
ber 1 piston is at Top Dead Center on the
compression stroke.
(8) Remove rocker arms with rocker shaft and
install a dummy shaft. The rocker arms should not
be disturbed and left on shaft.
(9) With air hose attached to spark plug adapter
installed in number 1 spark plug hole, apply 90 to
100 psi air pressure (620.5 to 689 kPa). This is to
hold valves in place while servicing components.
(10) Using Tool C-4682 or equivalent, compress
valve spring and remove retainer valve locks and
valve spring.
(11) The intake valve stem seals should be pushed
firmly and squarely over the valve guide using the
valve stem as guide.Do Not Forceseal against top
of guide. When installing the valve retainer locks,
compress the springonly enoughto install the
locks.
CAUTION: Do not pinch seal between retainer and
top of valve guide.
(12) Follow the same procedure on the remaining 5
cylinders using the firing sequence 1-2-3-4-5-6.Make
sure piston in cylinder is at TDC on the valve
spring that is being covered.
(13) Remove spark plug adapter tool.
(14) Remove dummy shaft and install rocker shaft
assembly and tighten screws to 28 N´m (250 in. lbs.).
(15) Install cylinder head covers tighten screws to
14 N´m (120 in. lbs.) and electrical connector to igni-
tion coils.
(16) Install Intake Manifold. Refer to Group 11,
Exhaust System and Intake Manifold for procedure.
(17) Connect negative cable to battery.
CYLINDER HEAD COVER
REMOVAL
NOTE: The cylinder head cover can be either an
isolated type (Fig. 32) or a non-isolated type.
FRONT CYLINDER HEAD COVER
(1) Disconnect ignition cables from spark plugs.
(2) Disconnect crankcase vent hose from cylinder
head cover.
(3) Remove front cylinder head cover bolts.
(4) Remove cylinder head cover and gasket.REAR CYLINDER HEAD COVER
(1) Disconnect negative cable from battery.
(2) Remove Wiper Unit. Refer to Group 8K, Wind-
shield Wipers and Washers for procedure.
(3) Remove intake manifold upper plenum. Refer
to Group 11, Exhaust System and Intake Manifold
for procedure.
(4) Disconnect PCV hose from cylinder head cover.
(5) Remove rear cylinder head cover bolts
(6) Remove cylinder head cover and gasket.
INSTALLATION
FRONT CYLINDER HEAD COVER
(1) Clean cylinder head and cover mating surfaces.
Inspect cylinder head cover surface for flatness.
Replace gasket as necessary.
(2) Install cylinder head cover and bolts.
(3) Tighten cylinder head cover bolts to the follow-
ing specifications:
²Non±isolatedcylinder head cover to 12 N´m
(105 in. lbs.).
²Isolatedcylinder head cover to 10 N´m (90 in.
lbs.) (Fig. 32).
(4) Connect crankcase vent hose.
(5) Connect ignition cables to spark plugs.
REAR CYLINDER HEAD COVER
(1) Clean cylinder head and cover mating surfaces.
Inspect cylinder head cover surface for flatness.
Replace gasket as necessary.
(2) Install cylinder head cover and bolts.
(3) Tighten cylinder head cover bolts to the follow-
ing specifications:
Fig. 32 Cylinder Head CoverÐIsolated Type
NS3.3/3.8L ENGINE 9 - 107
REMOVAL AND INSTALLATION (Continued)