Speed control DODGE RAM 1500 1998 2.G Owner's Guide

TRANSMISSION CONTROL
MODULE
DESCRIPTION
The Transmission Control Module (TCM) (Fig. 9)
may be sub-module within the Powertrain Control
Module (PCM), Engine Control Module (ECM - Diesel
only) (Fig. 10), or a standalone module, depending on
the vehicle engine. The PCM, and TCM when
equipped, is located at the right rear of the engine
compartment, near the right inner fender.
OPERATION
The Transmission Control Module (TCM) controls
all electronic operations of the transmission. The
TCM receives information regarding vehicle opera-
tion from both direct and indirect inputs, and selects
the operational mode of the transmission. Direct
inputs are hardwired to, and used specifically by the
TCM. Indirect inputs are shared with the TCM via
the vehicle communication bus.
Some examples ofdirect inputsto the TCM are:
²Battery (B+) voltage
²Ignition ªONº voltage
²Transmission Control Relay (Switched B+)
²Throttle Position Sensor
²Crankshaft Position Sensor
²Transmission Range Sensor
²Pressure Switches
²Transmission Temperature Sensor
²Input Shaft Speed Sensor
²Output Shaft Speed Sensor
²Line Pressure Sensor
Some examples ofindirect inputsto the TCM
are:²Engine/Body Identification
²Manifold Pressure
²Target Idle
²Torque Reduction Confirmation
²Engine Coolant Temperature
²Ambient/Battery Temperature
²DRBIIItScan Tool Communication
Based on the information received from these var-
ious inputs, the TCM determines the appropriate
shift schedule and shift points, depending on the
present operating conditions and driver demand.
This is possible through the control of various direct
and indirect outputs.
Some examples of TCMdirect outputsare:
²Transmission Control Relay
²Solenoids
²Torque Reduction Request
Some examples of TCMindirect outputsare:
²Transmission Temperature (to PCM)
²PRNDL Position (to BCM)
In addition to monitoring inputs and controlling
outputs, the TCM has other important responsibili-
ties and functions:
²Storing and maintaining Clutch Volume Indexes
(CVI)
²Storing and selecting appropriate Shift Sched-
ules
²System self-diagnostics
Fig. 9 PCM/TCM Location
1 - RIGHT FENDER
2 - TRANSMISSION CONTROL MODULE
3 - POWERTRAIN CONTROL MODULE
Fig. 10 Diesel ECM
1 - ENGINE CONTROL MODULE (ECM)
2 - ECM MOUNTING BOLT
3 - 50-WAY CONNECTOR
4 - SUPPORT PLATE
5 - 60-WAY CONNECTOR
8E - 20 ELECTRONIC CONTROL MODULESDR

²Diagnostic capabilities (with DRBIIItscan tool)
NOTE: If the TCM has been replaced, the ªQuick
Learn Procedureº must be performed. (Refer to 8 -
ELECTRICAL/ELECTRONIC CONTROL MODULES/
TRANSMISSION CONTROL MODULE - STANDARD
PROCEDURE)
BATTERY FEED
A fused, direct battery feed to the TCM is used for
continuous power. This battery voltage is necessary
to retain memory in the TCM. When the battery (B+)
is disconnected, this memory is lost. When the bat-
tery (B+) is restored, this memory loss is detected by
the TCM and a Diagnostic Trouble Code (DTC) is set.
CLUTCH VOLUME INDEXES (CVI)
An important function of the TCM is to monitor
Clutch Volume Indexes (CVI). CVIs represent the vol-
ume of fluid needed to compress a clutch pack.
The TCM monitors gear ratio changes by monitor-
ing the Input and Output Speed Sensors. The Input,
or Turbine Speed Sensor sends an electrical signal to
the TCM that represents input shaft rpm. The Out-
put Speed Sensor provides the TCM with output
shaft speed information.
By comparing the two inputs, the TCM can deter-
mine transmission gear position. This is important to
the CVI calculation because the TCM determines
CVIs by monitoring how long it takes for a gear
change to occur (Fig. 11).
Gear ratios can be determined by using the
DRBIIItScan Tool and reading the Input/Output
Speed Sensor values in the ªMonitorsº display. Gear
ratio can be obtained by dividing the Input Speed
Sensor value by the Output Speed Sensor value.
For example, if the input shaft is rotating at 1000
rpm and the output shaft is rotating at 500 rpm,
then the TCM can determine that the gear ratio is
2:1. In direct drive (3rd gear), the gear ratio changes
to 1:1. The gear ratio changes as clutches are applied
and released. By monitoring the length of time it
takes for the gear ratio to change following a shift
request, the TCM can determine the volume of fluid
used to apply or release a friction element.
The volume of transmission fluid needed to apply
the friction elements are continuously updated for
adaptive controls. As friction material wears, the vol-
ume of fluid need to apply the element increases.
Certain mechanical problems within the input
clutch assembly can cause inadequate or out-of-rangeelement volumes. Also, defective Input/Output Speed
Sensors and wiring can cause these conditions. The
following chart identifies the appropriate clutch vol-
umes and when they are monitored/updated:
CLUTCH VOLUMES
Clutch When UpdatedProper Clutch
Volume
L/R2-1 or 3-1
downshift45 to 134
2C3-2 kickdown
shift25 to 85
OD 2-3 upshift 30 to 100
4C 3-4 upshift 30 to 85
UD4-3 kickdown
shift30 to 100
Fig. 11 Example of CVI Calculation
1 - OUTPUT SPEED SENSOR
2 - OUTPUT SHAFT
3 - CLUTCH PACK
4 - SEPARATOR PLATE
5 - FRICTION DISCS
6 - INPUT SHAFT
7 - INPUT SPEED SENSOR
8 - PISTON AND SEAL
DRELECTRONIC CONTROL MODULES 8E - 21
TRANSMISSION CONTROL MODULE (Continued)

SHIFT SCHEDULES
As mentioned earlier, the TCM has programming
that allows it to select a variety of shift schedules.
Shift schedule selection is dependent on the follow-
ing:
²Shift lever position
²Throttle position²Engine load
²Fluid temperature
²Software level
As driving conditions change, the TCM appropri-
ately adjusts the shift schedule. Refer to the follow-
ing chart to determine the appropriate operation
expected, depending on driving conditions.
Schedule Condition Expected Operation
Extreme ColdOil temperature below -16É F -Park, Reverse, Neutral and 1st and
3rd gear only in D position, 2nd
gear only in Manual 2 or L
-No EMCC
Super ColdOil temperature between -12É F and
10É F- Delayed 2-3 upshift
- Delayed 3-4 upshift
- Early 4-3 coastdown shift
- High speed 4-2, 3-2, 2-1 kickdown
shifts are prevented
-Shifts at high throttle openings willl
be early.
- No EMCC
ColdOil temperature between 10É F and
36É F-Shift schedule is the same as
Super Cold except that the 2-3
upshifts are not delayed.
WarmOil temperature between 40É F and
80É F- Normal operation (upshift,
kickdowns, and coastdowns)
- No EMCC
HotOil temperature between 80É F and
240É F- Normal operation (upshift,
kickdowns, and coastdowns)
- Normal EMCC operation
OverheatOil temperature above 240É F or
engine coolant temperature above
244É F- Delayed 2-3 upshift
- Delayed 3-4 upshift
- 3rd gear FEMCC from 30-48 mph
- 3rd gear PEMCC above 35 mph
- Above 25 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
8E - 22 ELECTRONIC CONTROL MODULESDR
TRANSMISSION CONTROL MODULE (Continued)

STANDARD PROCEDURE
STANDARD PROCEDURE - TCM QUICK LEARN
The quick learn procedure requires the use of the
DRBtscan tool.
This program allows the electronic transmission
system to recalibrate itself. This will provide the
proper transmission operation. The quick learn pro-
cedure should be performed if any of the following
procedures are performed:
²Transmission Assembly Replacement
²Transmission Control Module Replacement
²Solenoid Pack 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 in PARK until
prompted to shift to overdrive
²The shift lever position must stay in overdrive
after the Shift to Overdrive prompt until the DRBt
indicates the procedure is complete
²The calculated oil temperature must be above
60É and below 200É
STANDARD PROCEDURE - DRIVE LEARN
When a transmission is repaired and a Quick
Learn procedure has been performed on the Trans-
mission Control Module (TCM), the following Drive
Learn procedure can be performed to fine tune any
shifts which are particularly objectionable.
NOTE: It is not necessary to perform the complete
Drive Learn procedure every time the TCM is Quick
Learned. Perform only the portions which target the
objectionable shift.
LEARN A SMOOTH 1ST NEUTRAL TO DRIVE SHIFT
Perform this procedure only if the complaint is for
a delayed or harsh shift the first time the transmis-
sion is put into gear after the vehicle is allowed to
set with the engine not running for at least 10 min-
utes. Use the following steps to have the TCM learn
the 1st N-D UD CVI.
NOTE: The transmission oil temperature must be
between 80 - 110ÉF (27 - 43ÉC).
(1) Start the engine only when the engine and
ignition have been off for at least ten (10) minutes.
(2) With the vehicle at a stop and the service
brake applied, record the 1st N-D UD CVI while per-forming a Neutral to Drive shift. The 1st N-D UD
CVI accounts for air entrapment in the UD clutch
that may occur after the engine has been off for a
period of time.
(3) Repeat Step 1 and Step 2 until the recorded 1st
N-D UD CVI value stabilizes.
NOTE: It is important that this procedure be per-
formed when the transmission temperature is
between 80 - 110ÉF (27 - 43ÉC). If this procedure
takes too long to complete fully for the allowed
transmission oil temperature, the vehicle may be
returned to the customer with an explanation that
the shift will improve daily during normal vehicle
usage. The TCM also learns at higher oil tempera-
tures, but these values (line pressure correction
values) are not available for viewing on the DRBT
III.
LEARN A SMOOTH NEUTRAL TO DRIVE GARAGE
SHIFT
Perform this procedure if the complaint is for a
delayed or harsh shift when the transmission is put
into gear after the vehicle has had its first shift. Use
the following steps to have the TCM learn the Norm
N-D UD CVI.
NOTE: The transmission oil temperature must be
between 80 - 110ÉF (27 - 43ÉC) to learn the UD CVI.
Additional learning occurs at temperatures as low
as 0ÉF and as high as 200ÉF. This procedure may be
performed at any temperature that experiences poor
shift quality. Although the UD CVI may not change,
shift quality should improve.
(1) Start the vehicle engine and shift to drive.
(2) Move the vehicle forward to a speed of at least
16 km/h (10 MPH) and come to a stop. This ensures
no air is present in the UD hydraulic circuit.
(3) Perform repeated N-D shifts at a stop while
pausing in Neutral for at least 2-3 seconds and mon-
itor Norm N-D UD CVI volume until the value stabi-
lizes. The value will change during the N-D shift.
This is normal since the UD value is different for the
N-D shift then the normal value shown which is used
for 4-3 coastdown and kickdowns. Perform repeated
shifts in this temperature range until the Norm N-D
UD CVI value stabilizes and the N-D shifts become
smooth.
LEARN THE 1ST 2-3 SHIFT AFTER A RESTART OR
SHIFT TO REVERSE
Use the following steps to have the TCM learn the
1st 2-3 shift OD CVI.
DRELECTRONIC CONTROL MODULES 8E - 23
TRANSMISSION CONTROL MODULE (Continued)

NOTE: The transmission oil temperature must be
above 80ÉF (27ÉC).
(1) With the vehicle engine running, select reverse
gear for over 2 seconds.
(2) Shift the transmission to Drive and accelerate
the vehicle from a stop at a steady 15 degree throttle
opening and perform a 2-3 shift while noting the 1st
2-3 OD CVI.
(3) Repeat Step 1 and Step 2 until the 1st 2-3
upshift becomes smooth and the 1st 2-3 OD CVI sta-
bilizes.
LEARN A SMOOTH 2-3 AND 3-4 UPSHIFT
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
Use the following steps to have the TCM learn the
OD and 4C CVI's.
(1) Accelerate the vehicle from a stop at a steady
15 degree throttle opening and perform multiple 1-2,
2-3, and 3-4 upshifts. The 2nd 2-3 shift following a
restart or shift to reverse will be shown during the
shift as a value between the 1st 2-3 OD CVI and the
normal OD CVI. Updates to the normal OD CVI will
occur after the 2nd shift into 3rd gear, following a
restart or shift to reverse.
(2) Repeat Step 1 until the 2-3 and 3-4 shifts
become smooth and the OD and 4C CVI become sta-
ble.
LEARN A SMOOTH 4-3 COASTDOWN AND PART
THROTTLE 4-3 KICKDOWN
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
Use the following steps to have the TCM learn the
UD shift volume.
(1) At a vehicle speed between 64-97 km/h (40-60
MPH), perform repeated 4-3 kickdown shifts.
(2) Repeat Step 1 until the UD volume becomes
somewhat stable and the shift becomes smooth.
LEARN A SMOOTH 1-2 UPSHIFT AND 3-2
KICKDOWN
Use the following steps to have the TCM learn the
2C shift volume.
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).(1) With a vehicle speed below 48 km/h (30 MPH)
and the transmission in 3rd gear, perform multiple
3-2 kickdowns.
(2) Repeat Step 1 until the 3-2 kickdowns become
smooth and the 2C CVI becomes stable.
LEARN A SMOOTH MANUAL 2-1 PULLDOWN
SHIFT AS WELL AS A NEUTRAL TO REVERSE
SHIFT
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
Use the following steps to have the TCM learn the
LR volume.
(1) With the vehicle speed around 40-48 km/h
(25-30 MPH) in Manual 2nd, perform manual pull-
downs to Low or 1st gear at closed throttle.
(2) Repeat Step 1 until the LR CVI becomes stable
and the manual 2-1 becomes smooth.
LEARN A SMOOTH NEUTRAL TO REVERSE SHIFT
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
(1) With the vehicle at a stop, perform Neutral to
Reverse shifts until the shift is smooth. An unlearned
Neutral to Reverse shift may be harsh or exhibit a
double bump.
(2) If any of the shifts are still not smooth after
the clutch volume stabilizes, an internal transmis-
sion problem may be present.
LEARN A SMOOTH 4-5 UPSHIFT
NOTE: The transmission oil temperature must be
above 110ÉF (43ÉC).
Use the following steps to have the TCM learn the
Alt 2C CVI.
(1) Accelerate the vehicle through 88 km/h
(55mph) at a steady 10-15 degree throttle opening
and perform multiple 4-5 upshifts.
(2) Repeat Step 1 until the 4-5 shift become
smooth and theAlt 2C CVI become stable. There is a
separate 2C volume used and learned for 4-5 shifts,
2CA. It is independent of the 2C CVI learned on 3-2
kickdowns.
8E - 24 ELECTRONIC CONTROL MODULESDR
TRANSMISSION CONTROL MODULE (Continued)

5.9L Diesel
The Camshaft Position Sensor (CMP) contains a
hall effect device. A rotating target wheel (tonewheel)
for the CMP is located on the front timing gear. This
hall effect device detects notches located on the tone-
wheel. As the tonewheel rotates, the notches pass the
tip of the CMP.
When the leading edge of the tonewheel notch
passes the tip of the CMP, the following occurs: The
interruption of magnetic field causes the voltage to
switch high resulting in a signal of approximately 5
volts.
When the trailing edge of the tonewheel notch
passes the tip of the CMP, the following occurs: The
change of the magnetic field causes the signal voltage
to switch low to 0 volts.
The CMP (Fig. 9) provides a signal to the Engine
Control Module (ECM) at all times when the engine
is running. The ECM uses the CMP information pri-
marily on engine start-up. Once the engine is run-
ning, the ECM uses the CMP as a backup sensor for
engine speed. The Crankshaft Position Sensor (CKP)
is the primary engine speed indicator for the engine
after the engine is running.
Fig. 7 CMP AND TONEWHEEL OPERATION - 4.7L
V-8
1 - NOTCHES
2 - RIGHT CYLINDER HEAD
3 - CAMSHAFT POSITION SENSOR
4 - TONEWHEEL
Fig. 8 CMP OPERATION - 5.7L ENGINE
1 - TIMING CHAIN COVER
2 - TONEWHEEL
3 - NOTCHES
Fig. 9 5.9L DIESEL CMP
1 - CMP
2 - FUEL INJECTION PUMP (BOTTOM)
3 - ELECTRONIC CONTROL MODULE (ECM)
4 - ECM ELEC. CONNECTOR
5 - CMP ELEC. CONNECTOR
6 - CMP MOUNTING BOLT
7 - BACK OF TIMING GEAR COVER
8I - 8 IGNITION CONTROLDR
CAMSHAFT POSITION SENSOR (Continued)

Base ignition timing is not adjustable.By con-
trolling the coil ground circuit, the PCM is able to set
the base timing and adjust the ignition timing
advance. This is done to meet changing engine oper-
ating conditions.
The ignition coil is not oil filled. The windings are
embedded in an epoxy compound. This provides heat
and vibration resistance that allows the ignition coil
to be mounted on the engine.
Because of coil design, spark plug cables (second-
ary cables) are not used with the 4.7L V-8 engine.
5.7L V-8
The ignition system is controlled by the Powertrain
Control Module (PCM) on all engines.
A ªwasted sparkº system is used on the 5.7L
engine combining paired, or dual-firing coils, and 2
spark plugs per cylinder. The coils and spark plugs
are connected with paired, secondary high-voltage
cables.
Each cylinder is equipped with 1 dual-output coil.
Meaning one coil mounts directly over one of the
dual spark plugs for 1 high-voltage output. A second
high-voltage output is supplied directly from the
same coil (using a plug cable) to one of the dual
spark plugs on a corresponding (paired) cylinder on
the opposite cylinder bank.
Each coil fires 2 spark plugs simultaneously on
each of the cylinder banks (one cylinder on compres-
sion stroke and one cylinder on exhaust stroke).
EXAMPLE :When the #1 cylinder is on compression
stroke and ready for spark, the #1 coil will fire one of
the dual spark plugs on the #1 cylinder (directly
below the coil). The other dual spark plug on the #1
cylinder will be fired by the #6 coil. At the same
time, the #1 coil will fire a ªwasted sparkº to one of
the dual spark plugs at the #6 cylinder as coil #6 also
fires a ªwasted sparkº to one of the dual spark plugs
at the #6 cylinder.
The firing order is paired at cylinders 1/6, 2/3, 4/7,
5/8. Basic cylinder firing order is 1±8±4±3±6±5±7±2.
Battery voltage is supplied to all of the ignition
coils positive terminals from the ASD relay. If the
PCM does not see a signal from the crankshaft and
camshaft sensors (indicating the ignition key is ON
but the engine is not running), it will shut down the
ASD circuit.
Base ignition timing is not adjustable on the
5.7L V-8 engine.By controlling the coil ground cir-
cuits, the PCM is able to set the base timing and
adjust the ignition timing advance. This is done to
meet changing engine operating conditions.
The PCM adjusts ignition timing based on inputs it
receives from:
²The engine coolant temperature sensor
²The crankshaft position sensor (engine speed)²The camshaft position sensor (crankshaft posi-
tion)
²The manifold absolute pressure (MAP) sensor
²The throttle position sensor
²Transmission gear selection
REMOVAL
3.7L V-6
An individual ignition coil is used for each spark
plug (Fig. 15). The coil fits into machined holes in the
cylinder head. A mounting stud/nut secures each coil
to the top of the intake manifold (Fig. 16). The bot-
tom of the coil is equipped with a rubber boot to seal
the spark plug to the coil. Inside each rubber boot is
a spring. The spring is used for a mechanical contact
between the coil and the top of the spark plug. These
rubber boots and springs are a permanent part of the
coil and are not serviced separately. An o-ring (Fig.
15) is used to seal the coil at the opening into the cyl-
inder head.
(1) Depending on which coil is being removed, the
throttle body air intake tube or intake box may need
to be removed to gain access to coil.
(2) Disconnect electrical connector from coil by
pushing downward on release lock on top of connec-
tor and pull connector from coil.
(3) Clean area at base of coil with compressed air
before removal.
(4) Remove coil mounting nut from mounting stud
(Fig. 16).
(5) Carefully pull up coil from cylinder head open-
ing with a slight twisting action.
(6) Remove coil from vehicle.
4.7L V-8
An individual ignition coil is used for each spark
plug (Fig. 15). The coil fits into machined holes in the
cylinder head. A mounting stud/nut secures each coil
to the top of the intake manifold (Fig. 17). The bot-
tom of the coil is equipped with a rubber boot to seal
the spark plug to the coil. Inside each rubber boot is
a spring. The spring is used for a mechanical contact
between the coil and the top of the spark plug. These
rubber boots and springs are a permanent part of the
coil and are not serviced separately. An o-ring (Fig.
15) is used to seal the coil at the opening into the cyl-
inder head.
(1) Depending on which coil is being removed, the
throttle body air intake tube or intake box may need
to be removed to gain access to coil.
(2) Disconnect electrical connector (Fig. 17) from
coil by pushing downward on release lock on top of
connector and pull connector from coil.
(3) Clean area at base of coil with compressed air
before removal.
DRIGNITION CONTROL 8I - 13
IGNITION COIL (Continued)

Knock sensors contain a piezoelectric material
which constantly vibrates and sends an input voltage
(signal) to the PCM while the engine operates. As the
intensity of the crystal's vibration increases, the
knock sensor output voltage also increases.
The voltage signal produced by the knock sensor
increases with the amplitude of vibration. The PCM
receives the knock sensor voltage signal as an input.
If the signal rises above a predetermined level, the
PCM will store that value in memory and retard
ignition timing to reduce engine knock. If the knock
sensor voltage exceeds a preset value, the PCM
retards ignition timing for all cylinders. It is not a
selective cylinder retard.
The PCM ignores knock sensor input during engine
idle conditions. Once the engine speed exceeds a
specified value, knock retard is allowed.
Knock retard uses its own short term and long
term memory program.
Long term memory stores previous detonation
information in its battery-backed RAM. The maxi-
mum authority that long term memory has over tim-
ing retard can be calibrated.
Short term memory is allowed to retard timing up
to a preset amount under all operating conditions (as
long as rpm is above the minimum rpm) except at
Wide Open Throttle (WOT). The PCM, using short
term memory, can respond quickly to retard timing
when engine knock is detected. Short term memory
is lost any time the ignition key is turned off.
NOTE: Over or under tightening the sensor mount-
ing bolts will affect knock sensor performance, pos-
sibly causing improper spark control. Always use
the specified torque when installing the knock sen-
sors.
REMOVAL
3.7L V-6 / 4.7L V-8
The 2 knock sensors are bolted into the cylinder
block under the intake manifold (Fig. 20). or (Fig.
21).
NOTE: The left sensor is identified by an identifica-
tion tag (LEFT). It is also identified by a larger bolt
head. The Powertrain Control Module (PCM) must
have and know the correct sensor left/right posi-
tions. Do not mix the sensor locations.
(1) Disconnect knock sensor dual pigtail harness
from engine wiring harness. This connection is made
near rear of engine.
(2) Remove intake manifold. Refer to Engine sec-
tion.(3) Remove sensor mounting bolts (Fig. 20), or
(Fig. 21). Note foam strip on bolt threads. This foam
is used only to retain the bolts to sensors for plant
assembly. It is not used as a sealant. Do not apply
any adhesive, sealant or thread locking compound to
these bolts.
(4) Remove sensors from engine.
5.7L V8
Two sensors are used. Each sensor is bolted into
the outside of cylinder block below the exhaust man-
ifold (Fig. 22).
(1) Raise vehicle.
(2) Disconnect knock sensor electrical connector.
(3) Remove sensor mounting bolt (Fig. 22). Note
foam strip on bolt threads. This foam is used only to
retain the bolts to sensors for plant assembly. It is
not used as a sealant. Do not apply any adhesive,
sealant or thread locking compound to these bolts.
(4) Remove sensor from engine.
INSTALLATION
3.7L V-6 / 4.7L V-8
NOTE: The left sensor is identified by an identifica-
tion tag (LEFT). It is also identified by a larger bolt
head. The Powertrain Control Module (PCM) must
have and know the correct sensor left/right posi-
tions. Do not mix the sensor locations.
Fig. 20 KNOCK SENSOR Ð 3.7L V-6
1 - KNOCK SENSORS (2)
2 - MOUNTING BOLTS
DRIGNITION CONTROL 8I - 15
KNOCK SENSOR (Continued)

Sandwiched between the rear cover and the lens,
hood and mask unit is the cluster housing. The
molded plastic cluster housing serves as the carrier
for the cluster circuit board and circuitry, the cluster
connector receptacles, the RKE interface connector,
the gauges, a Light Emitting Diode (LED) for each
cluster indicator, two VFD units, an audible tone
generator, the cluster overlay, the gauge pointers, the
odometer/trip odometer switch and the switch button.
The cluster overlay is a laminated plastic unit. The
dark, visible, outer surface of the overlay is marked
with all of the gauge dial faces and graduations, but
this layer is also translucent. The darkness of this
outer layer prevents the cluster from appearing clut-
tered or busy by concealing the cluster indicators
that are not illuminated, while the translucence of
this layer allows those indicators and icons that are
illuminated to be readily visible. The underlying
layer of the overlay is opaque and allows light from
the LED for each of the various indicators and the
incandescent illumination lamps behind it to be visi-
ble through the outer layer of the overlay only
through predetermined stencil-like cutouts. A rectan-
gular opening in the overlay at the base of both the
speedometer and tachometer dial faces has a smoked
clear lens through which the illuminated VFD units
can be viewed.
Several versions of the EMIC module are offered
on this model. These versions accommodate all of the
variations of optional equipment and regulatory
requirements for the various markets in which the
vehicle will be offered. The microprocessor-based
EMIC utilizes integrated circuitry and information
carried on the Programmable Communications Inter-
face (PCI) data bus network along with several hard
wired analog and multiplexed inputs to monitor sen-
sors and switches throughout the vehicle. In response
to those inputs, the internal circuitry and program-
ming of the EMIC allow it to control and integrate
many electronic functions and features of the vehicle
through both hard wired outputs and the transmis-
sion of electronic message outputs to other electronic
modules in the vehicle over the PCI data bus. (Refer
to 8 - ELECTRICAL/ELECTRONIC CONTROL
MODULES/COMMUNICATION - DESCRIPTION -
PCI BUS).
Besides typical instrument cluster gauge and indi-
cator support, the electronic functions and features
that the EMIC supports or controls include the fol-
lowing:
²Audible Warnings- The EMIC electronic cir-
cuit board is equipped with an audible tone generator
and programming that allows it to provide various
audible alerts to the vehicle operator, including
chime tones and beep tones. An electromechanical
relay is also soldered onto the circuit board to pro-duce audible clicks that emulate the sound of a con-
ventional turn signal or hazard warning flasher.
(Refer to 8 - ELECTRICAL/CHIME/BUZZER -
DESCRIPTION).
²Brake Lamp Control- The EMIC provides
electronic brake lamp request messages to the Front
Control Module (FCM) located on the Integrated
Power Module (IPM) for brake lamp control, exclud-
ing control of the Center High Mounted Stop Lamp
(CHMSL), which remains controlled by a direct hard
wired output of the brake lamp switch.
²Brake Transmission Shift Interlock Control
- The EMIC monitors inputs from the brake lamp
switch, ignition switch, and the Transmission Range
Sensor (TRS), then controls a high-side driver output
to operate the Brake Transmission Shift Interlock
(BTSI) solenoid that locks and unlocks the automatic
transmission gearshift selector lever on the steering
column.
²Cargo Lamp Control- The EMIC provides
direct control of cargo lamp operation with a load
shedding (battery saver) feature which will automat-
ically turn off the cargo lamp if it remains on after a
timed interval.
²Central Locking- The EMIC provides support
for the central locking feature of the power lock sys-
tem. This feature will lock or unlock all doors based
upon the input from the door cylinder lock switch.
Door cylinder lock switches are used only on models
equipped with the optional Vehicle Theft Security
System (VTSS).
²Door Lock Inhibit- The EMIC inhibits locking
of the doors with the power lock switch when the key
is in the ignition switch and the driver side front
door is ajar. However, operation of the door locks is
not inhibited under the same conditions when the
Lock button of the optional RKE transmitter is
depressed.
²Enhanced Accident Response- The EMIC
monitors an input from the Airbag Control Module
(ACM) and, following an airbag deployment, will
immediately disable the power lock output, unlock all
doors by activating the power unlock output, then
enables the power lock output. This feature, like all
other enhanced accident response features, is depen-
dent upon a functional vehicle electrical system fol-
lowing the vehicle impact event.
²Exterior Lighting Control- The EMIC pro-
vides electronic head lamp and/or park lamp request
messages to the Front Control Module (FCM) located
on the Integrated Power Module (IPM) for the appro-
priate exterior lamp control of standard head and
park lamps, as well as optional front fog lamps. This
includes support for headlamp beam selection and
the optical horn feature, also known as flash-to-pass.
DRINSTRUMENT CLUSTER 8J - 3
INSTRUMENT CLUSTER (Continued)

²Exterior Lighting Fail-safe- In the absence of
a headlamp switch input, the EMIC will turn on the
cluster illumination lamps and provide electronic
headlamp low beam and park lamp request messages
to the Front Control Module (FCM) located on the
Integrated Power Module (IPM) for default exterior
lamp operation. The FCM will also provide default
park lamp and headlamp low beam operation and the
EMIC will turn on the cluster illumination lamps if
there is a failure of the electronic data bus commu-
nication between the EMIC and the FCM.
²Heated Seat Control- The EMIC monitors
inputs from the ignition switch and electronic engine
speed messages from the Powertrain Control Module
(PCM) to control a high side driver output to the
heated seat switch Light Emitting Diode (LED) indi-
cators. This input allows the heated seat switches to
wake up the heated seat module if the switch is actu-
ated. The EMIC will de-energize the heated seat
switch LED indicators, which deactivates the heated
seat system, if the ignition switch is turned to any
position except On or Start, or if the engine speed
message indicates zero. (Refer to 8 - ELECTRICAL/
HEATED SEATS - DESCRIPTION).
²Interior Lamp Load Shedding- The EMIC
provides a battery saver feature which will automat-
ically turn off all interior lamps that remain on after
a timed interval of about fifteen minutes.
²Interior Lamps - Enhanced Accident
Response- The EMIC monitors inputs from the Air-
bag Control Module (ACM) and the Powertrain Con-
trol Module (PCM) to automatically turn on the
interior lighting after an airbag deployment event
ten seconds after the vehicle speed is zero. The inte-
rior lighting remains illuminated until the key is
removed from the ignition switch lock cylinder, at
which time the interior lighting returns to normal
operation and control. This feature, like all other
enhanced accident response features, is dependent
upon a functional vehicle electrical system following
the vehicle impact event.
²Interior Lighting Control- The EMIC moni-
tors inputs from the interior lighting switch, the door
ajar switches, the cargo lamp switch, the reading
lamp switches, and the Remote Keyless Entry (RKE)
module to provide courtesy lamp control. This
includes support for timed illuminated entry with
theater-style fade-to-off and courtesy illumination
defeat features.
²Lamp Out Indicator Control- The EMIC
monitors electronic lamp outage messages from the
Front Control Module (FCM) located on the Inte-
grated Power Module (IPM) in order to provide lamp
out indicator control for the headlamps (low and high
beams), turn signal lamps, and the brake lamps
(excluding CHMSL).²Panel Lamps Dimming Control- The EMIC
provides a hard wired 12-volt Pulse-Width Modulated
(PWM) output that synchronizes the dimming level
of all hard wired panel lamps dimmer controlled
lamps with that of the cluster illumination lamps.
²Parade Mode- The EMIC provides a parade
mode (also known as funeral mode) that allows all
Vacuum-Fluorescent Display (VFD) units in the vehi-
cle to be illuminated at full (daytime) intensity while
driving during daylight hours with the exterior
lamps turned on.
²Power Locks- The EMIC monitors inputs from
the power lock switches and the Remote Keyless
Entry (RKE) receiver module (optional) to provide
control of the power lock motors through high side
driver outputs to the power lock motors. This
includes support for rolling door locks (also known as
automatic door locks), automatic door unlock, a door
lock inhibit mode, and central locking (with the
optional Vehicle Theft Security System only). (Refer
to 8 - ELECTRICAL/POWER LOCKS - DESCRIP-
TION).
²Remote Keyless Entry- The EMIC supports
the optional Remote Keyless Entry (RKE) system fea-
tures, including support for the RKE Lock, Unlock
(with optional driver-door-only unlock, and unlock-
all-doors), Panic, audible chirp, optical chirp, illumi-
nated entry modes, an RKE programming mode, as
well as optional Vehicle Theft Security System
(VTSS) arming (when the proper VTSS arming con-
ditions are met) and disarming.
²Remote Radio Switch Interface- The EMIC
monitors inputs from the optional remote radio
switches and then provides the appropriate electronic
data bus messages to the radio to select the radio
operating mode, volume control, preset station scan
and station seek features.
²Rolling Door Locks- The EMIC provides sup-
port for the power lock system rolling door locks fea-
ture (also known as automatic door locks). This
feature will automatically lock all unlocked doors
each time the vehicle speed reaches twenty-four kilo-
meters-per-hour (fifteen miles-per-hour). Following
an automatic lock event, if the driver side front door
is opened first after the ignition is turned to the Off
position, all doors will be automatically unlocked.
²Turn Signal & Hazard Warning Lamp Con-
trol- The EMIC provides electronic turn and hazard
lamp request messages to the Front Control Module
(FCM) located on the Integrated Power Module (IPM)
for turn and hazard lamp control. The EMIC also
provides an audible click at one of two rates to emu-
late normal and bulb out turn or hazard flasher oper-
ation based upon electronic lamp outage messages
from the FCM, and provides an audible turn signal
on chime warning if a turn is signalled continuously
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INSTRUMENT CLUSTER (Continued)