2001 CHRYSLER VOYAGER heating

HEATED SEAT SYSTEM
TABLE OF CONTENTS
page page
HEATED SEAT SYSTEM
DESCRIPTION............................7
OPERATION.............................8
DRIVER HEATED SEAT SWITCH
DESCRIPTION............................8
OPERATION.............................9
DIAGNOSIS AND TESTING..................9
HEATED SEAT SWITCH...................9
REMOVAL..............................10
INSTALLATION...........................10
HEATED SEAT ELEMENT
DESCRIPTION...........................10
OPERATION.............................11DIAGNOSIS AND TESTING.................11
HEATED SEAT ELEMENT.................11
HEATED SEAT SENSOR
DESCRIPTION...........................11
DIAGNOSIS AND TESTING.................11
HEATED SEAT SENSOR..................11
PASSENGER HEATED SEAT SWITCH
DESCRIPTION...........................11
OPERATION.............................11
DIAGNOSIS AND TESTING.................12
HEATED SEAT SWITCH..................12
REMOVAL..............................13
INSTALLATION...........................13
HEATED SEAT SYSTEM
DESCRIPTION
Individually controlled driver and passenger side
electrically heated front seats are available factory-
installed optional equipment on this model, when it
is also equipped with the power seat option. The
heated seat system allows both the driver and the
front seat passenger the option to select one of twoseat heating ranges, Low or High, or to turn the indi-
vidual seat heaters Off using the heated seat
switches located in the instrument panel center bezel
near the bottom of the HVAC outlets (Fig. 1). The
heated seat switch circuit operates on ignition
switched battery current supplied through a fuse in
the intelligent power module, only when the ignition
switch is in the On position.
This section covers the following components of the
heated seat system:
²Heated seat elements
²Heated seat sensors
²Heated seat switches
The Heated seat module (or memory heated seat
module) can be found in the Electronic Control Mod-
ules section of the service manual.
The heated seat system also relies upon resources
shared with other electronic modules in the vehicle
over the Programmable Communications Interface
(PCI) J1850 data bus network. The J1850 (PCI) data
bus network allows the sharing of sensor informa-
tion. This helps to reduce wire harness complexity,
internal controller hardware, and component sensor
current loads. At the same time, this system provides
increased reliability, enhanced diagnostics, and
allows the addition of many new feature capabilities.
For diagnosis of these electronic modules or of the
J1850 (PCI) data bus network, the use of a DRB IIIt
scan tool, or equivalent and the proper Diagnostic
Procedures manual are recommended.
The electronic modules that may affect heated seat
system operation are as follows:
²Body Control Module (BCM)- Refer toBody
Control Modulein Electronic Control Modules for
more information.
Fig. 1 HEATED SEAT SWITCHES
RSHEATED SEAT SYSTEM8G-7

²Remote Keyless Entry Module (RKE)- Refer
toRemote Keyless Entry Modulein Power Locks
for more information.
²Electronic Vehicle Information Center
(EVIC)- Refer toElectronic Vehicle Information
Centerin Overhead Console for more information.
²Heated Seat Module (HSM)- Refer toHeated
Seat Modulein Electronic Control Modules for more
information.
²Memory Heated Seat Module (MHSM)-If
the vehicle is equipped with the Memory System,
refer toMemory Seat Mirror Module (MSMM)in
Electronic Control Modules for more information.
Refer toWiring Diagramsfor complete circuit
diagrams. Following are general descriptions of the
major components in the heated seat system.
OPERATION
The heated seat system will only operate when the
ignition switch is in the On position, and the surface
temperature at the front seat heating element sen-
sors is below the designed temperature set points of
the system. The heated seat system will not operate
in ambient temperatures greater than about 41É C
(105É F). The front seat heating elements and sensors
are hard wired to the Heated Seat Module (HSM) or
the Memory Heated Seat Module (MHSM).
The heated seat switches are hard wired to the
Body Control Module (BCM). The BCM monitors the
heated seat switch inputs, then sends heated seat
switch status messages to the HSM or MHSM over
the Programmable Communications Interface J1850
(PCI) data bus. The HSM or MHSM contains the con-
trol logic for the heated seat system. The HSM or
MHSM responds to the heated seat switch status
messages, ignition switch status messages, and the
front seat heating element sensor inputs by control-
ling the output to the front seat heating elements
through integral solid-state relays.
When a seat heater is turned on, the sensor
located on the seat cushion electric heater element
provides the HSM or MHSM with an input indicating
the surface temperature of the seat cushion. If the
surface temperature input is below the temperature
set point for the selected Low or High heated seat
switch position, the HSM or MHSM energizes the
integral solid-state relay, which supplies battery cur-
rent to the heating elements in the seat cushion and
back. When the sensor input indicates the correct
temperature set point has been achieved, the HSM or
MHSM de-energizes the solid-state relay. The HSM
or MHSM will continue to cycle the solid-state relay
as needed to maintain the temperature set point.
The HSM or MHSM and the seat heater elements
operate on non-switched battery current supplied
through the power seat fuse in the intelligent powermodule. However, the HSM or MHSM will automati-
cally turn off the heating elements if it detects an
open in the sensor circuit, a short in the heating ele-
ment circuit causing an excessive current draw, or
when the ignition switch is turned to the Off posi-
tion.
See the owner's manual in the vehicle glove box for
more information on the features, use and operation
of the heated seat system.
DRIVER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 2). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazzard, rear window
wiper and washer switches. The heated seat switches
provide a resistor multiplexed signal to the Body
Control Module (BCM) through separate hard wired
circuits. Each switch has an Off, Low, and High posi-
tion so that both the driver and the front seat pas-
senger can select a preferred seat heating mode.
Each switch has two Light-Emitting Diodes (LED)
which light to indicate that the heater for the seat is
turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
Fig. 2 HEATED SEAT SWITCHES
8G - 8 HEATED SEAT SYSTEMRS
HEATED SEAT SYSTEM (Continued)

inoperative heated seat switch(es) and a good ground.
There should be no continuity. If OK, go to Step 7. If
not OK, repair the shorted seat heater switch sensor
ground circuit as required.
(7) Check for continuity between the seat heater
switch sensor ground circuit cavities of the instru-
ment panel wire harness connector for the in opera-
tive heated seat switch and the instrument panel
wire harness connector for the BCM. There should be
continuity. If OK, go to Step 8. If not OK, repair the
open seat heater switch sensor ground circuit as
required.
(8) Check for continuity between the seat heater
switch mux circuit cavity of the instrument panel
wire harness connector for the inoperative heated
seat switch and a good ground. There should be no
continuity. If OK, go to Step 9. If not OK, repair the
shorted seat heater switch mux circuit as required.
(9) Check for continuity between the seat heater
switch mux circuit cavity of the instrument panel
wire harness connector for the inoperative heated
seat switch and the instrument panel wire harness
connector for the BCM. There should be continuity. If
OK, use a DRB IIItscan tool and the proper Diag-
nostic Procedures manual to test the BCM. If not
OK, repair the open seat heater switch mux circuit
as required.
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 toInstrument Panel Center Bezelin the
Body section for the procedure.
(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 that secure
the heated seat switch to the back of the instrumentpanel center bezel. Tighten the screws to 1.5 N´m (13
in. lbs.) (Fig. 4).
(3) Install the center bezel onto the instrument
panel. Refer toInstrument Panel Center Bezelin
the Body section for the procedure.
(4) Reconnect the battery negative cable.
HEATED SEAT ELEMENT
DESCRIPTION
The heated seat system includes two seat heating
elements in each front seat, one for the seat cushion
and the other for the seat back. The two elements for
each seat that are connected in series with the
Heated Seat Module (HSM). The temperature sensor
is a Negative Temperature Coefficient (NTC) ther-
mistor. One temperature sensor is used for each seat,
and it is located on the seat cushion heating element
for all models.
The seat heating elements are sewn into the seat
cushion cover trim and seat back cover trim units.
The heated seat elements and the temperature sen-
sor cannot be adjusted or repaired and, if faulty or
damaged, the seat cushion or seat back assembly
must be replaced. Refer toSeat CushionorSeat
Backin the Removal and Installation section of
Body for the seat cushion and seat back service pro-
cedures.
Fig. 4 SWITCH RETAINING SCREWS
1 - HEATED SEAT SWITCH ASSEMBLY
2 - RETAINING SCREWS
8G - 10 HEATED SEAT SYSTEMRS
DRIVER HEATED SEAT SWITCH (Continued)

OPERATION
The heated seat elements resist the flow of electri-
cal current. When battery current is passed through
the elements, the energy lost by the resistance of the
elements to the current flow is released in the form
of heat. The temperature sensor is a NTC thermistor.
When the temperature of the seat cushion cover
rises, the resistance of the sensor decreases. The
HSM or MHSM supplies a five-volt current to one
side of each sensor, and monitors the voltage drop
through the sensor on a return circuit. The MSM or
MHSM uses this temperature sensor input to moni-
tor the temperature of the seat, and regulates the
current flow to the seat heating elements accordingly.
DIAGNOSIS & TESTING - HEATED SEAT
ELEMENT
The wire harness connectors for the seat cushion
and seat back heating elements are located under the
seat, near the rear edge of the seat cushion frame.
For circuit descriptions and diagrams, refer to Group
8W, Wiring Diagrams.
SEAT CUSHION
(1) Disconnect and isolate the battery negative
cable. Unplug the 4-way heated seat cushion wire
harness connector.
(2) Check for continuity between the two heated
seat driver circuit cavities of the seat cushion cover
half of the heated seat cushion wire harness connec-
tor. There should be continuity. If OK, go to Step 3. If
not OK, replace the faulty seat cushion cover.
(3) Check for continuity between one of the heated
seat driver circuit cavities of the seat cushion cover
half of the heated seat cushion wire harness connec-
tor and the seat cushion frame. There should be no
continuity. If OK, go to the Seat Back test. If not OK,
replace the faulty seat cushion cover.
SEAT BACK
(1) Disconnect and isolate the battery negative
cable. Unplug the 2-way heated seat back wire har-
ness connector.
(2) Check for continuity between the heated seat
driver circuit cavity and the ground circuit cavity of
the seat back cover half of the heated seat back wire
harness connector. There should be continuity. If OK,
go to Step 3. If not OK, replace the faulty seat back
cover.
(3) Check for continuity between the heated seat
driver circuit cavity of the seat back cover half of the
heated seat back wire harness connector and the seat
back frame. There should be no continuity. If OK,
test the heated seat sensor as described in this
group. If not OK, replace the faulty seat back cover.
HEATED SEAT SENSOR
DESCRIPTION
The heated seat temperature sensor is a Negative
Temperature Coefficient (NTC) thermistor. One tem-
perature sensor is used for each seat, and is inte-
grated into the seat cushion heating element.
DIAGNOSIS & TESTING - HEATED SEAT
SENSOR
For complete circuit diagrams, refer toWiring
Diagrams.
(1) Disconnect and isolate the battery negative
cable. Disconnect the 4-way heated seat cushion ele-
ment wire harness connector from the power seat
wire harness. The power seat wire harness connec-
tors for the seat cushion and seat back heating ele-
ments are secured to a bracket located under the
rear edge of the seat cushion frame.
(2) Using an ohmmeter, check the resistance
between the seat sensor circuit and the seat temper-
ature sensor input circuit cavities of the 4-way
heated seat cushion element wire harness connector.
The sensor resistance should be between 2 kilohms
at 15É C (60É F) and 200 kilohms at 30É C (85É F). If
not OK, replace the faulty seat cushion cover trim
and sensor unit.
PASSENGER HEATED SEAT
SWITCH
DESCRIPTION
The heated seat switches are mounted in the
instrument panel center bezel (Fig. 5). The two three-
position rocker-type switches, one switch for each
front seat, are incorporated into one large switch
assembly that also includes the hazzard, rear window
wiper and washer switches. The heated seat switches
provide a resistor multiplexed signal to the Body
Control Module (BCM) through separate hard wired
circuits. Each switch has an Off, Low, and High posi-
tion so that both the driver and the front seat pas-
senger can select a preferred seat heating mode.
Each switch has two Light-Emitting Diodes (LED)
which light to indicate that the heater for the seat is
turned on.
The heated seat switches and their LEDs cannot
be repaired. If either switch or LED is faulty or dam-
aged, the entire switch assembly must be replaced.
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
RSHEATED SEAT SYSTEM8G-11
HEATED SEAT ELEMENT (Continued)

AUTO SHUT DOWN RELAY
DESCRIPTION
The relay is located in the Power Distribution Cen-
ter (PDC). For the location of the relay within the
PDC, refer to the PDC cover for location. Check elec-
trical terminals for corrosion and repair as necessary
OPERATION
The ASD sense circuit informs the PCM when the
ASD relay energizes. A 12 volt signal at this input
indicates to the PCM that the ASD has been acti-
vated. This input is used only to sense that the ASD
relay is energized.
When energized, the ASD relay supplies battery
voltage to the fuel injectors, ignition coils and the
heating element in each oxygen sensor. If the PCM
does not receive 12 volts from this input after
grounding the ASD relay, it sets a Diagnostic Trouble
Code (DTC).
When energized, the ASD relay provides power to
operate the injectors, ignition coil, generator field, O2
sensor heaters (both upstream and downstream), and
also provides a sense circuit to the PCM for diagnos-
tic purposes. The PCM energizes the ASD any time
there is a Crankshaft Position sensor signal that
exceeds a predetermined value. The ASD relay can
also be energized after the engine has been turned
off to perform an O2 sensor heater test, if vehicle is
equipped with OBD II diagnostics.
As mentioned earlier, the PCM energizes the ASD
relay during an O2 sensor heater test. This test is
performed only after the engine has been shut off.
The PCM still operates internally to perform several
checks, including monitoring the O2 sensor heaters.
CAMSHAFT POSITION
SENSOR
DESCRIPTION
The camshaft position sensorfor the 3.3/3.8L is
mounted in the front of the timing case cover (Fig. 7)
and the camshaft position sensor for the 2.4L is
mounted on the end of the cylinder head (Fig. 4).
OPERATION
The camshaft position sensor provides cylinder
identification to the Powertrain Control Module
(PCM) (Fig. 2). The sensor generates pulses as
groups of notches on the camshaft sprocket pass
underneath it (Fig. 3). The PCM keeps track of
crankshaft rotation and identifies each cylinder by
the pulses generated by the notches on the camshaftsprocket. Four crankshaft pulses follow each group of
camshaft pulses.
When the PCM receives 2 cam pulses followed by
the long flat spot on the camshaft sprocket, it knows
that the crankshaft timing marks for cylinder 1 are
next (on driveplate). When the PCM receives one
camshaft pulse after the long flat spot on the
sprocket, cylinder number 2 crankshaft timing marks
are next. After 3 camshaft pulses, the PCM knows
cylinder 4 crankshaft timing marks follow. One cam-
shaft pulse after the 3 pulses indicates cylinder 5.
The 2 camshaft pulses after cylinder 5 signals cylin-
der 6 (Fig. 3). The PCM can synchronize on cylinders
1or4.
When metal aligns with the sensor, voltage goes
low (less than 0.3 volts). When a notch aligns with
the sensor, voltage switches high (5.0 volts). As a
group of notches pass under the sensor, the voltage
switches from low (metal) to high (notch) then back
to low. The number of notches determine the amount
of pulses. If available, an oscilloscope can display the
square wave patterns of each timing event.
Top Dead Center (TDC) does not occur when
notches on the camshaft sprocket pass below the cyl-
inder. TDC occurs after the camshaft pulse (or
pulses) and after the 4 crankshaft pulses associated
with the particular cylinder. The arrows and cylinder
call outs on Figure 4 represent which cylinder the
flat spot and notches identify, they do not indicate
TDC position.
REMOVAL - 2.4L
The camshaft position sensor is mounted to the
rear of the cylinder head.
(1) Remove the negative battery cable.
Fig. 2 Camshaft Position Sensor
1 - ELECTRICAL CONNECTOR
2 - O-RING
3 - PAPER SPACER
RSIGNITION CONTROL8I-3

POWER MIRRORS
TABLE OF CONTENTS
page page
POWER MIRRORS
DESCRIPTION...........................45
OPERATION.............................45
DIAGNOSIS AND TESTING.................45
POWER MIRRORS......................45
AUTOMATIC DAY / NIGHT MIRROR
DESCRIPTION...........................46
OPERATION.............................46
DIAGNOSIS AND TESTING.................47AUTOMATIC DAY/NIGHT MIRROR..........47
REMOTE SWITCH
DIAGNOSIS AND TESTING.................48
REMOTE SWITCH......................48
REMOVAL..............................48
INSTALLATION...........................48
SIDEVIEW MIRROR
REMOVAL..............................48
POWER MIRRORS
DESCRIPTION
If equipped with power mirrors, the control switch
is located on the instrument panel to the left of the
headlamp switch.
OPERATION
The power mirrors are connected to battery feed at
all times. Each mirror head contains two electric
motors, two drive mechanisms, an electric heating
element, and the mirror glass. If the vehicle is
equipped with the optional memory system, each
mirror head also contains both a horizontal and a
vertical motor position sensor. One motor and drive
controls mirror up-and-down movement, and the
other controls right-and-left movement.
An optional driver side outside electrochromic mir-
ror is able to automatically change its reflectance
level. This mirror is controlled by the circuitry of the
automatic day/night inside rear view mirror. A thin
layer of electrochromic material between two pieces
of conductive glass make up the face of the mirror.
Two photocell sensors on the inside rear view mirror
are used to monitor light levels and adjust the reflec-tance of both the inside and driver side outside mir-
rors. This change in reflectance helps to reduce the
glare of headlamps approaching the vehicle from the
rear. (Refer to 8 - ELECTRICAL/POWER MIRRORS/
AUTOMATIC DAY / NIGHT MIRROR - DESCRIP-
TION) for more information on this system.
The motors which operate the mirrors are part of
the mirror assembly and cannot be serviced sepa-
rately.
DIAGNOSIS AND TESTING - POWER MIRRORS
(1) Remove Power Mirror Switch. (Refer to 8 -
ELECTRICAL/POWER MIRRORS/POWER MIRROR
SWITCH - REMOVAL).
(2) Disconnect wiring harness connector to the
power mirror switch and headlamp switch.
(3) Using two jumper wires:
²Connect one to a 12-volt source
²Connect the other to a good body ground
²Refer to the Mirror Test Chart for wire hookups
at the switch connector (Fig. 1).
(4) If results shown in table are not obtained,
check for broken or shorted circuit, or replace mirror
assembly as necessary.
RSPOWER MIRRORS8N-45

NOTE: Plastigage is available in a variety of clear-
ance ranges. Use the most appropriate range for
the specifications you are checking.
(4) Install the proper crankshaft bearings to
achieve the specified bearing clearances. (Refer to 9 -
ENGINE/ENGINE BLOCK/CRANKSHAFT MAIN
BEARINGS - STANDARD PROCEDURE) (Refer to 9
- ENGINE/ENGINE BLOCK/CONNECTING ROD
BEARINGS - STANDARD PROCEDURE)
REMOVAL - ENGINE ASSEMBLY
(1) Perform fuel pressure release procedure (Refer
to 14 - FUEL SYSTEM/FUEL DELIVERY - STAN-
DARD PROCEDURE)
(2) Disconnect battery negative cable.
(3) Remove air cleaner housing and inlet tube.
(4) Disconnect the fuel line from fuel rail. (Refer to
14 - FUEL SYSTEM/FUEL DELIVERY/FUEL LINES
- STANDARD PROCEDURE)
(5) Disconnect all vacuum hoses.
(6) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(7) Remove radiator fans. (Refer to 7 - COOLING/
ENGINE/RADIATOR FAN - REMOVAL)
(8) Remove radiator upper and lower hoses.
(9) Disconnect automatic transmission cooler lines
and plug.(10) Disconnect transmission shift linkage and
electrical connectors.
(11) Disconnect throttle body linkage.
(12) Disconnect engine wiring harness.
(13) Disconnect heater hoses from heater (Fig. 5).
(14) Discharge air conditioning system. (Refer to
24 - HEATING & AIR CONDITIONING/PLUMBING
- STANDARD PROCEDURE)
(15) Hoist vehicle and remove front wheels and
tires.
(16) Remove accessory drive belt splash shield.
(17) Remove accessory drive belts. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(18) Remove axle shafts. (Refer to 3 - DIFFEREN-
TIAL & DRIVELINE/HALF SHAFT - REMOVAL)
(19) Drain engine oil and remove oil filter. (Refer
to 9 - ENGINE/LUBRICATION/OIL - STANDARD
PROCEDURE)
(20) Remove crossmember cradle plate (Fig. 6).
(21) Disconnect exhaust pipe from manifold (Fig.
7).
(22) Remove engine front mount and bracket from
engine. (Refer to 9 - ENGINE/ENGINE MOUNTING/
FRONT MOUNT - REMOVAL)
(23) Remove structural collar. (Refer to 9 -
ENGINE/ENGINE BLOCK/STRUCTURAL COVER -
REMOVAL)
Fig. 5 HEATER HOSES - 2.4L
1 - HEATER HOSES TO HEATER 3 - HEATER HOSE TO ENGINE - SUPPLY AND RETURN
2 - BOLT - HEATER TUBE SUPPORT
9 - 12 ENGINE 2.4LRS
ENGINE 2.4L (Continued)

OPERATION
The cylinder head closes the combustion chamber,
allowing the pistons to compress the fuel/air mixture
for ignition. The valves are actuated by the lobe pro-
files on the camshaft to open and close at specified
duration to either allow clean air in the combustion
chamber or the exhaust gases out; depending on the
stroke of the engine.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING). An
engine cylinder head gasket leaking between adja-
cent cylinders will result in approximately a 50±70%
reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
CHEMICAL TEST METHOD
Combustion leaks into the cooling system can also
be checked by using Bloc-Chek Kit C-3685-A or
equivalent. Perform test following the procedures
supplied with the tool kit.
REMOVAL - CYLINDER HEAD
(1) Perform fuel system pressure release procedure
before attempting any repairs.(Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY - SPECIFICA-
TIONS)
(2) Disconnect battery negative cable.
(3) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(4) Remove air filter housing and inlet tube.
(5) Remove upper intake manifold. (Refer to 9 -
ENGINE/MANIFOLDS/INTAKE MANIFOLD -
REMOVAL)
Fig. 13 Cylinder Head and Camshafts
1 - CAMSHAFT BEARING CAPS
2 - PLUG
3 - CAMSHAFT
4 - CYLINDER HEAD
5 - CAMSHAFT OIL SEAL
RSENGINE 2.4L9-23
CYLINDER HEAD (Continued)