2001 DODGE RAM Heat

(7) Remove the radio receiver from the instrument
panel. Refer to Audio, Radio for the procedures.
(8) Pull the antenna cable out through the radio
receiver opening in the instrument panel.
(9) Untie the cord or twine from the instrument
panel antenna cable connector, leaving the cord or
twine in place of the cable in the instrument panel.
(10) Remove the antenna cable from the instru-
ment panel.
INSTALLATION
(1) Tie the end of the cord or twine that was used
during instrument panel antenna cable removal
securely to the connector on the end of the antenna
cable being installed into the instrument panel. This
cord will be used to pull or ªfishº the cable back into
position.
(2) Using the cord or twine, pull the antenna cable
through the radio receiver opening from under the
instrument panel.
(3) Install the radio receiver onto the instrument
panel. Refer to Audio, Radio for the procedures.
(4) Reach through the glove box opening to engage
the antenna cable with the retainer clips on the back
of the instrument panel.
(5) Install the glove box onto the instrument panel.
Refer to Body, Instrument Panel for the procedures.
(6) Untie the cord or twine from the instrument
panel antenna cable connector.
(7) Reach under the passenger side of the instru-
ment panel near the right cowl side inner panel to
reconnect the two halves of the radio antenna coaxial
cable connector. Wrap the connection with a piece of
foam tape.
(8) Engage the coaxial cable connector with the
retainer clip located on the bottom of the heater-A/C
housing.
(9) Reconnect the battery negative cable.
RADIO
DESCRIPTION
Available factory-installed radio receivers for this
model include an AM/FM/cassette (RAS sales code),
an AM/FM/cassette/5-band graphic equalizer with CD
changer control feature (RBN sales code), an AM/FM/
CD/3-band graphic equalizer (RBR sales code), or an
AM/FM/CD/cassette/3-band graphic equalizer (RAZ
sales code). The factory-installed RAZ sales code
radio receivers can also communicate on the Chrysler
Collision Detection (CCD) data bus network through
a separate two-way wire harness connector. All facto-
ry-installed receivers are stereo Electronically Tuned
Radios (ETR) and include an electronic digital clock
function.These radio receivers can only be serviced by an
authorized radio repair station. See the latest War-
ranty Policies and Procedures manual for a current
listing of authorized radio repair stations.
All vehicles are equipped with an Ignition-Off
Draw (IOD) fuse that is removed when the vehicle is
shipped from the factory. This fuse feeds various
accessories that require battery current when the
ignition switch is in the Off position, including the
clock. The IOD fuse is removed to prevent battery
discharge during vehicle storage.
When removing or installing the IOD fuse, it is
important that the ignition switch be in the Off posi-
tion. Failure to place the ignition switch in the Off
position can cause the radio display to become scram-
bled when the IOD fuse is removed and replaced.
Removing and replacing the IOD fuse again, with the
ignition switch in the Off position, will correct the
scrambled display condition.
The IOD fuse should be checked if the radio or
clock displays are inoperative. The IOD fuse is
located in the junction block. Refer to the fuse layout
label on the back of the instrument panel fuse access
panel for IOD fuse identification and location.
OPERATION
The radio receiver operates on fused battery cur-
rent that is available only when the ignition switch is
in the On or Accessory positions. The electronic digi-
tal clock function of the radio operates on fused bat-
tery current supplied through the IOD fuse,
regardless of the ignition switch position.
For more information on the features, setting pro-
cedures, and control functions for each of the avail-
able factory-installed radio receivers, see the owner's
manual in the vehicle glove box. For complete circuit
diagrams, refer to the appropriate wiring informa-
tion. The wiring information includes wiring dia-
grams, proper wire and connector repair procedures,
details of wire harness routing and retention, connec-
tor pin-out information and location views for the
various wire harness connectors, splices and grounds.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - RADIO
If the vehicle is equipped with the optional remote
radio switches located on the steering wheel and the
problem being diagnosed is related to one of the
symptoms listed below, be certain to check the
remote radio switches and circuits. Refer to Audio,
Remote Radio Switch prior to attempting radio diag-
nosis or repair.
²Stations changing with no remote radio switch
input
8A - 10 AUDIOBR/BE
INSTRUMENT PANEL ANTENNA CABLE (Continued)

(5) Disconnect the instrument panel wire harness
connectors and the antenna coaxial cable connector
from the receptacles on the rear of the radio receiver.
(6) If so equipped, remove the screw that secures
the ground wire to the back of the radio receiver
chassis.
(7) Remove the radio receiver from the instrument
panel.
INSTALLATION
(1) Position the radio receiver to the instrument
panel.
(2) If so equipped, install and tighten the screw
that secures the ground wire to the back of the radio
receiver chassis. Tighten the screw to 7 N´m (65 in.
lbs.).
(3) Reconnect the instrument panel wire harness
connectors and the antenna coaxial cable connector
to the receptacles on the rear of the radio receiver.
(4) Position the radio receiver into the mounting
hole in the instrument panel.
(5) Install and tighten the two screws that secure
the radio receiver to the instrument panel. Tighten
the screws to 5 N´m (45 in. lbs.).
(6) Install the cluster bezel onto the instrument
panel.
(7) Reconnect the battery negative cable.
RADIO NOISE SUPPRESSION
COMPONENTS
DESCRIPTION
Radio Frequency Interference (RFI) and Electro-
Magnetic Interference (EMI) noise suppression is
accomplished primarily through circuitry internal to
the radio receivers. These internal suppression
devices are only serviced as part of the radio receiver.
External suppression devices that are used on this
vehicle to control RFI or EMI noise include the fol-
lowing:
²Radio antenna base ground
²Radio receiver chassis ground wire or strap
²Engine-to-body ground straps
²Cab-to-bed ground strap
²Heater core ground strap
²Resistor-type spark plugs
²Radio suppression-type secondary ignition wir-
ing.
For more information on the spark plugs and sec-
ondary ignition components, refer to Electrical, Igni-
tion Control.
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - RADIO NOISE
SUPPRESSION COMPONENTS
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, REFER TO ELECTRICAL, RESTRAINTS
BEFORE ATTEMPTING ANY STEERING WHEEL,
STEERING COLUMN, OR INSTRUMENT PANEL
COMPONENT DIAGNOSIS OR SERVICE. FAILURE
TO TAKE THE PROPER PRECAUTIONS COULD
RESULT IN ACCIDENTAL AIRBAG DEPLOYMENT
AND POSSIBLE PERSONAL INJURY.
For complete circuit diagrams, refer to the appro-
priate wiring information. The wiring information
includes wiring diagrams, proper wire and connector
repair procedures, details of wire harness routing
and retention, connector pin-out information and
location views for the various wire harness connec-
tors, splices and grounds. Inspect the ground paths
and connections at the following locations:
²Blower motor
²Cab-to-bed ground strap
²Electric fuel pump
²Engine-to-body ground straps
²Generator
²Ignition module
²Heater core ground strap
²Radio antenna base ground
²Radio receiver chassis ground wire or strap
Fig. 9 Radio Receiver Connections - Typical
1 - ANTENNA CABLE
2 - RADIO
3 - INSTRUMENT PANEL WIRING
4 - GROUND WIRE
8A - 12 AUDIOBR/BE
RADIO (Continued)

(3) For the right side only on vehicles equipped
with a 3.9L, 5.2L or 5.9L engine, position the engine-
to-body ground strap eyelet over the right rear valve
cover stud.
(4) For the right side only on vehicles equipped
with a 3.9L, 5.2L or 5.9L engine, install and tighten
the nut that secures the engine-to-body ground strap
eyelet to the right rear valve cover stud. Tighten the
nut to 3.9 N´m (35 in. lbs.).
(5) Position the engine-to-body ground strap to the
dash panel.
(6) Install and tighten the screw that secures the
engine-to-body ground strap eyelet to the dash panel.
Tighten the screw to 3.9 N´m (35 in. lbs.).
CAB-TO- BED GROUND STRAP
REMOVAL
(1) Raise and support the vehicle.
(2) Remove the screw that secures the cab-to-bed
ground strap eyelet to the front crossmember of the
cargo bed (Fig. 13).
(3) Remove the screw that secures the cab-to-bed
ground strap eyelet to the cab floor panel.
(4) Remove the cab-to-bed ground strap from the
vehicle.
INSTALLATION
(1) Position the cab-to-bed ground strap to the cab
floor panel.(2) Install and tighten the screw that secures the
cab-to-bed ground strap eyelet to the cab floor panel.
Tighten the screw to 3.9 N´m (35 in. lbs.).
(3) Position the cab-to-bed ground strap to the
front crossmember of the cargo bed.
(4) Install and tighten the screw that secures the
cab-to-bed ground strap eyelet to the front crossmem-
ber of the cargo bed. Tighten the screw to 3.9 N´m
(35 in. lbs.).
(5) Lower the vehicle.
HEATER CORE GROUND
STRAP
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the glove box from the instrument
panel. Refer to Body, Instrument Panel for the proce-
dures.
(3) Reach through the instrument panel glove box
opening to access and remove the nut that secures
the heater core ground strap eyelet to the stud on the
dash panel (Fig. 14).
(4) Remove the heater core ground strap eyelet
from the stud on the dash panel.
(5) Remove the screw that secures the heater core
ground strap eyelet and the heater core tube retain-
ing strap to the top of the heater-A/C housing.
Fig. 12 Engine-To-Body Ground Strap Remove/
Install - V10 Engine
1 - GROUND STRAP
2 - GROUND STRAP
3 - SCREW
4 - SCREWFig. 13 Cab-To-Bed Ground Strap Remove/Install
1 - BED CROSSMEMBER
2 - GROUND STRAP
3 - CAB FLOOR PANEL
4 - SCREWS
8A - 14 AUDIOBR/BE
ENGINE-TO-BODY GROUND STRAP (Continued)

(6) Remove the heater core ground strap from the
top of the heater-A/C housing.
INSTALLATION
(1) Position the heater core ground strap and the
heater core tube retaining strap to the top of the
heater-A/C housing.
(2) Install and tighten the screw that secures the
heater core ground strap eyelet and the heater core
tube retaining strap to the top of the heater-A/C
housing. Tighten the screw to 2.2 N´m (20 in. lbs.).
(3) Position the heater core ground strap eyelet
over the stud on the dash panel.
(4) Install and tighten the nut that secures the
heater core ground strap eyelet to the stud on the
dash panel. Tighten the nut to 3.9 N´m (35 in. lbs.).
(5) Install the glove box onto the instrument panel.
Refer to Body, Instrument Panel for the procedures.
(6) Reconnect the battery negative cable.
REMOTE SWITCHES
DESCRIPTION
A remote radio switch option is available on models
equipped with the AM/FM/CD/cassette/3-band
graphic equalizer (RAZ sales code) radio receiver and
the high-line Central Timer Module (CTM). Refer to
Electrical, Body Control/Central Timer Module for
more information on this component.
Two rocker-type switches (Fig. 15) are mounted in
the sides of the rear (instrument panel side) steeringwheel trim cover. The switch on the left side is the
seek switch and has seek up, seek down, and preset
station advance functions. The switch on the right
side is the volume control switch and has volume up,
and volume down functions. The two switches are
retained in mounting holes located on each side of
the rear steering wheel trim cover by four latches
that are integral to the switches.
The remote radio switches share a common steer-
ing wheel wire harness with the vehicle speed control
switches. The steering wheel wire harness is con-
nected to the instrument panel wire harness through
the clockspring. Refer to Electrical, Clockspring for
more information on this component.
OPERATION
The remote radio switches are resistor multiplexed
units that are hard wired to the high-line or pre-
mium CTM through the clockspring. The CTM mon-
itors the status of the remote radio switches and
sends the proper switch status messages on the
Chrysler Collision Detection (CCD) data bus network
to the radio receiver. The electronic circuitry within
the radio is programmed to respond to these remote
radio switch status messages by adjusting the radio
settings as requested.
For diagnosis of the CTM or the CCD data bus, the
use of a DRBIIItscan tool and the proper Diagnostic
Procedures manual are recommended. For more
information on the features and control functions for
each of the remote radio switches, see the owner's
Fig. 14 Heater Core Ground Strap Remove/Install
1 - GROUND STRAP
2 - NUT
3 - HEATER-A/C HOUSING
4 - DASH PANEL
Fig. 15 Remote Radio Switches
1 - PRESET SEEK
2-UP
3 - SEEK
4 - VOLUME
5 - DOWN
BR/BEAUDIO 8A - 15
HEATER CORE GROUND STRAP (Continued)

(8) Turn the radio receiver off. Turn the ignition
switch to the Off position. Disconnect and isolate the
battery negative cable. Disconnect the wire harness
connector for the Infinity-amplified front door-
mounted speaker on the same side of the vehicle as
the inoperative speaker. Check both the amplified
feed (+) circuit and amplified return (±) circuit cavi-
ties for the inoperative speaker location in the body
half of the front door speaker wire harness connector
for continuity to ground. In each case, there should
be no continuity. If OK, go to Step 9. If not OK,
repair the shorted amplified feed (+) and/or amplified
return (±) circuit(s) as required.
(9) Disconnect the wire harness connector at the
inoperative speaker. Check for continuity between
the amplified feed (+) circuit cavities in the body half
of the wire harness connector for the Infinity-ampli-
fied front door-mounted speaker on the same side of
the vehicle as the inoperative speaker and the inop-
erative speaker wire harness connector. Repeat the
check between the amplified return (±) circuit cavi-
ties in the body half of the wire harness connector for
the Infinity-amplified front door-mounted speaker on
the same side of the vehicle as the inoperative
speaker and the inoperative speaker wire harness
connector. In each case, there should be continuity. If
OK, go to Step 10. If not OK, repair the open ampli-
fied feed (+) and/or amplified return (±) circuit(s) as
required.
(10) Check the resistance between the amplified
feed (+) circuit and amplified return (±) circuit cavi-
ties for the inoperative speaker in the body half of
the wire harness connector for the Infinity-amplified
front door-mounted speaker on the same side of the
vehicle as the inoperative speaker. The meter should
read between 2.5 and 4 ohms (speaker resistance). If
OK, replace the faulty front door-mounted Infinity
speaker and amplifier unit. If not OK, replace the
faulty A-pillar or rear-mounted Infinity speaker.
A-PILLAR TWEETER SPEAKER
REMOVAL
The A-pillar-mounted tweeters are used only with
the optional Infinity premium speaker package.
(1) Disconnect and isolate the battery negative
cable.
(2) If the vehicle is so equipped, remove the grab
handle from the A-pillar. Refer to Body, Interior for
the procedures.
(3) Disengage the trim from the A-pillar. Refer to
Body, Interior for the procedures.
(4) Pull the trim away from the A-pillar far enough
to access the tweeter wire harness connector (Fig.
18).(5) Disconnect the body wire harness connector
from the A-pillar tweeter wire harness connector.
(6) Remove the trim and tweeter from the A-pillar
as a unit.
(7) Disengage the tweeter wire harness retainers
from the heat stakes on the back of the A-pillar trim.
(8) Disengage the tweeter from the A-pillar trim
by pushing out on the tweeter firmly and evenly from
the inside of the trim until it unsnaps from the
mounting hole.
(9) Remove the tweeter from the mounting hole in
the A-pillar trim.INSTALLATION
(1) Position the tweeter into the mounting hole in
the A-pillar trim.
(2) Install the tweeter onto the A-pillar trim by
pushing in on the tweeter firmly and evenly from the
outside of the trim until it snaps into the mounting
hole.
(3) Use a suitable tape or adhesive to secure the
tweeter wire harness to the inside of the A-pillar
trim.
(4) Position the trim and tweeter to the A-pillar as
a unit.
Fig. 18 A-Pillar Tweeter Remove/Install
1 - NUT
2 - WIRE HARNESS CONNECTOR
3 - MOULDING
4 - HANDLE
5 - PLUG
6 - SCREW
7 - TWEETER
BR/BEAUDIO 8A - 19
SPEAKER (Continued)

external connector receptacles that connect it to the
vehicle electrical system through one (base) or two
(high-line/premium) take outs with connectors from
the instrument panel wire harness.
The base version of the CTM is used on base mod-
els of this vehicle. It is also sometimes referred to as
the Integrated Electronic Module (IEM). The base
version of the CTM combines the functions of a
chime module and an intermittent wipe module in a
single unit. The high-line version of the CTM is used
on high-line vehicles. The high-line CTM provides all
of the functions of the base version of the CTM, but
also is used to control and integrate many additional
electronic functions and features included on high-
line models. The premium version of the CTM is the
same as the high-line version, but is used only on
models equipped with the heated seat option.
The high-line and premium versions of the CTM
utilize integrated circuitry and information carried
on the Chrysler Collision Detection (CCD) data bus
network along with many hard wired inputs to mon-
itor many sensor and switch inputs throughout the
vehicle. In response to those inputs, the internal cir-
cuitry and programming of the CTM allow it to con-
trol and integrate many electronic functions and
features of the vehicle through both hard wired out-
puts and the transmission of electronic message out-
puts to other electronic modules in the vehicle over
the CCD data bus.
The features that the CTM supports or controls
include the following:
²Automatic Door Lock- The high-line/premium
CTM provides an optional automatic door lock fea-
ture (also known as rolling door locks). This is a pro-
grammable feature.
²Central Locking- The high-line/premium CTM
provides an optional central locking/unlocking fea-
ture.
²Chimes- All versions of the CTM provide chime
service through an integral chime tone generator.
²Courtesy Lamps- The high-line/premium CTM
provides courtesy lamp control with timed load shed-
ding.
²Door Lock Inhibit- The high-line/premium
CTM provides a door lock inhibit feature.
²Enhanced Accident Response- The high-line/
premium CTM provides an optional enhanced acci-
dent response feature. This is a programmable
feature.
²Heated Seats- The premium CTM controls the
optional heated seat system by controlling the opera-
tion of the heated seat relay.
²Illuminated Entry- The high-line/premium
CTM provides a timed illuminated entry feature.²Intermittent Wipe Control- All versions of
the CTM provide control of the intermittent wipe
delay, and wipe-after-wash features.
²Panic Mode- The high-line/premium CTM pro-
vides support for the optional RKE system panic
mode features.
²Power Lock Control- The high-line/premium
CTM provides the optional power lock system fea-
tures, including support for the automatic door lock
and door lock inhibit modes.
²Programmable Features- The high-line/pre-
mium CTM provides support for certain programma-
ble features.
²Remote Keyless Entry- The high-line/pre-
mium CTM provides the optional Remote Keyless
Entry (RKE) system features, including support for
the RKE Lock (with optional horn chirp), Unlock,
Panic, and illuminated entry modes, as well as the
ability to be programmed to recognize up to four
RKE transmitters. The RKE horn chirp is a program-
mable feature.
²Remote Radio Switch Interface- The high-
line/premium CTM monitors and transmits the sta-
tus of the optional remote radio switches.
²Speed Sensitive Intermittent Wipe Control-
The high-line/premium CTM provides the speed sen-
sitive intermittent wipe feature.
²Vehicle Theft Alarm- The high-line/premium
CTM provides control of the optional Vehicle Theft
Alarm features, including support for the central
locking/unlocking mode.
Hard wired circuitry connects the CTM to the elec-
trical system of the vehicle. These hard wired circuits
are integral to several wire harnesses, which are
routed throughout the vehicle and retained by many
different methods. These circuits may be connected to
each other, to the vehicle electrical system and to the
CTM through the use of a combination of soldered
splices, splice block connectors, and many different
types of wire harness terminal connectors and insu-
lators. Refer to the appropriate wiring information.
The wiring information includes wiring diagrams,
proper wire and connector repair procedures, further
details on wire harness routing and retention, as well
as pin-out and location views for the various wire
harness connectors, splices and grounds.
All versions of the CTM for this model are serviced
only as a complete unit. Many of the electronic fea-
tures in the vehicle controlled or supported by the
high-line or premium versions of the CTM are pro-
grammable using the DRBIIItscan tool. In addition,
the high-line/premium CTM software is Flash com-
patible, which means it can be reprogrammed using
Flash reprogramming procedures. However, if any of
the CTM hardware components are damaged or
faulty, the entire CTM unit must be replaced. The
8E - 2 ELECTRONIC CONTROL MODULESBR/BE
BODY CONTROL/CENTRAL TIMER MODULE (Continued)

base version of the CTM and the hard wired inputs
or outputs of all CTM versions can be diagnosed
using conventional diagnostic tools and methods;
however, for diagnosis of the high-line or premium
versions of the CTM or the CCD data bus, the use of
a DRBIIItscan tool is required. Refer to the appro-
priate diagnostic information.
OPERATION
The Central Timer Module (CTM) is designed to
control and integrate many of the electronic features
and functions of the vehicle. The base version of the
CTM monitors only hard wired inputs and responds
with the proper hard wired outputs. The microproces-
sor-based high-line/premium version of the CTM
monitors many hard wired switch and sensor inputs
as well as those resources it shares with other elec-
tronic modules in the vehicle through its communica-
tion over the Chrysler Collision Detection (CCD) data
bus network. The internal programming and all of
these inputs allow the high-line/premium CTM
microprocessor to determine the tasks it needs to
perform and their priorities, as well as both the stan-
dard and optional features that it should provide.
The high-line/premium CTM programming then per-
forms those tasks and provides those features
through both CCD data bus communication with
other electronic modules and through hard wired out-
puts to a number of circuits, relays, and actuators.
These outputs allow the high-line/premium CTM the
ability to control numerous accessory systems in the
vehicle.
All versions of the CTM operate on battery current
received through fuses in the Junction Block (JB) on
a non-switched fused B(+) circuit, a fused ignition
switch output (st-run) circuit (base version only), and
a fused ignition switch output (run-acc) circuit (high-
line/premium version only). This arrangement allows
the CTM to provide some features regardless of the
ignition switch position, while other features will
operate only with the ignition switch in the Acces-
sory, On, and/or Start positions. All versions of the
CTM are grounded through their connector and take
out of the instrument panel wire harness. The high-
line/premium CTM has another ground received
through a second connector and take out of the
instrument panel wire harness. The first ground cir-
cuit receives ground through a take out with an eye-
let terminal connector of the instrument panel wire
harness that is secured by a nut to a ground stud
located on the left instrument panel end bracket,
while the second ground circuit (high-line/premium
version only) receives ground through a take out with
an eyelet terminal connector of the instrument panel
wire harness that is secured by a nut to a ground
stud located on the back of the instrument panelarmature above the inboard side of the instrument
panel steering column opening.
The high-line/premium CTM monitors its own
internal circuitry as well as many of its input and
output circuits, and will store a Diagnostic Trouble
Code (DTC) in electronic memory for any failure it
detects. These DTCs can be retrieved and diagnosed
using a DRBIIItscan tool. Refer to the appropriate
diagnostic information.
HARD WIRED INPUTS
The hard wired inputs to the CTM include the fol-
lowing:
²CCD bus± - high-line/premium version only
²CCD bus+ - high-line/premium version only
²Cylinder lock switch mux - high-line premium
version only
²Driver door ajar switch sense
²Fused B(+)
²Fused ignition switch output (run-acc) - high-
line/premium version only
²Fused ignition switch output (st-run) - base ver-
sion only
²Ground (one circuit - base version, two circuits -
high-line/premium version)
²Key-in ignition switch sense
²Passenger door ajar switch sense - high-line/pre-
mium version only
²Power door lock motor B(+) lock - high-line/pre-
mium version only
²Power door lock motor B(+) unlock - high-line/
premium version only
²Radio control mux - high-line/premium version
only
²Tone request signal
²Washer switch sense
²Wiper park switch sense
²Wiper switch mode sense
²Wiper switch mode signal
HARD WIRED OUTPUTS
The hard wired outputs of the CTM include the fol-
lowing:
²CCD bus± - high-line/premium version only
²CCD bus+ - high-line/premium version only
²Courtesy lamp switch output - high-line/pre-
mium version only
²Door lock driver - high-line/premium version
only
²Door unlock driver - high-line/premium version
only
²Headlamp relay control - high-line/premium ver-
sion only
²Heated seat relay control - premium version
only
BR/BEELECTRONIC CONTROL MODULES 8E - 3
BODY CONTROL/CENTRAL TIMER MODULE (Continued)

NOTE: ECM Outputs:
After inputs are received by the ECM, certain sen-
sors, switches and components are controlled or reg-
ulated by the ECM. These are consideredECM
Outputs.These outputs are for:
²CCD bus (+) circuits
²CCD bus (-) circuits
²CKP and APPS outputs to the PCM
²Data link connection for DRB scan tool
²Five volt sensor supply
²Fuel injection pump
²Fuel injection pump relay
²(FPCM) Fuel Pump Control Module
²Fuel transfer (lift) pump
²Intake manifold air heater relays #1 and #2 con-
trol circuits
²Malfunction indicator lamp (Check engine lamp)
²Oil pressure gauge/warning lamp
²PCM
²Wait-to-start warning lamp
²Water-In-Fuel (WIF) warning lamp
REMOVAL
The ECM is bolted to the engine block behind the
fuel filter (Fig. 16).
(1) Record any Diagnostic Trouble Codes (DTC's)
found in the PCM or ECM.To avoid possible voltage spike damage to either
the Powertrain Control Module (PCM) or ECM, igni-
tion key must be off, and negative battery cables
must be disconnected before unplugging ECM con-
nectors.
(2) Disconnect both negative battery cables at both
batteries.
(3) Remove 50±way electrical connector bolt at
ECM (Fig. 16). Note: Connector bolt is female 4mm
hex head. To remove bolt, use a ball-hex bit or ball-
hex screwdriver such as Snap-Ont4mm SDABM4
(5/32º may also be used). As bolt is being removed,
very carefully remove connector from ECM.
(4) Remove three ECM mounting bolts and remove
ECM from vehicle.
INSTALLATION
Do not apply paint to back of ECM. Poor ground
will result.
(1) Clean ECM mounting points at engine block.
(2) Position ECM to engine block and install 3
mounting bolts. Tighten bolts to 24 N´m (18 ft. lbs.).
(3) Check pin connectors in ECM and 50±way con-
nector for corrosion or damage. Repair as necessary.
(4) Clean pins in 50±way electrical connector with
a quick-dry electrical contact cleaner.
(5) Very carefully install 50±way connector to
ECM. Tighten connector hex bolt.
(6) Install battery cables.
(7)Turn key to ON position. Without starting
engine, slowly press throttle pedal to floor and
then slowly release. This step must be done
(one time) to ensure accelerator pedal position
sensor calibration has been learned by ECM. If
not done, possible DTC's may be set.
(8) Use DRB scan tool to erase any stored compan-
ion DTC's from PCM.
POWERTRAIN CONTROL
MODULE
DESCRIPTION - PCM
The Powertrain Control Module (PCM) is located
in the engine compartment (Fig. 17). The PCM is
referred to as JTEC.
DESCRIPTION - MODES OF OPERATION
As input signals to the Powertrain Control Module
(PCM) change, the PCM adjusts its response to the
output devices. For example, the PCM must calculate
different injector pulse width and ignition timing for
idle than it does for wide open throttle (WOT).
The PCM will operate in two different modes:
Open Loop and Closed Loop.
Fig. 16 Engine Control Module (ECM) Location and
Mounting
1 - ENGINE CONTROL MODULE (ECM)
2 - HEX HEADED BOLT
3 - 50-WAY CONNECTOR
4 - FUEL TRANSFER PUMP
5 - MOUNTING BOLTS (3)
8E - 14 ELECTRONIC CONTROL MODULESBR/BE
ENGINE CONTROL MODULE (Continued)