2001 DODGE RAM ECU

(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)

(5) Reconnect the body wire harness connector to
the A-pillar tweeter wire harness connector.
(6) Engage the trim onto the A-pillar. Refer to
Body, Interior for the procedures.
(7) If the vehicle is so equipped, install the grab
handle onto the A-pillar. Refer to Body, Interior for
the procedures.
(8) Reconnect the battery negative cable.
FRONT DOOR SPEAKER
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim panel from the front door.
Refer to Body, Door Front for the procedures.
(3) Remove the four screws that secure the
speaker to the front door inner panel (Fig. 19).
(4) Pull the speaker away from the mounting hole
in the front door inner panel far enough to access the
speaker wire harness connector.
(5) Disconnect the speaker wire harness connector
from the front door wire harness connector.
(6) Remove the speaker from the front door inner
panel.
INSTALLATION
(1) Position the speaker to the front door inner
panel.
(2) Reconnect the speaker wire harness connector
to the front door wire harness connector.
(3) Position the speaker into the mounting hole in
the front door inner panel.
(4) Install and tighten the four screws that secure
the speaker to the front door inner panel. Tighten
the screws to 4 N´m (35 in. lbs.).
(5) Install the trim panel onto the front door. Refer
to Body, Door Front for the procedures.
(6) Reconnect the battery negative cable.
REAR CAB SIDE PANEL
SPEAKER
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim from the rear cab side panel.
Refer to Body, Interior for the procedures.
(3) Remove the two screws that secure the speaker
to the cab side inner panel (Fig. 20) or (Fig. 21).
(4) Pull the speaker away from the mounting hole
in the cab side inner panel far enough to access the
body wire harness connector.
(5) Disconnect the body wire harness connector
from the speaker connector receptacle.
Fig. 19 Front Door Speaker Remove/Install
1 - CLIP
2 - FRONT DOOR INNER PANEL
3 - WIRE HARNESS CONNECTOR
4 - SCREW
5 - SPEAKERFig. 20 Rear Speaker Remove/Install - Standard Cab
1 - CLIP
2 - SPEAKER
3 - SCREW
4 - WIRE HARNESS CONNECTOR
5 - CAB SIDE INNER PANEL
8A - 20 AUDIOBR/BE
A-PILLAR TWEETER SPEAKER (Continued)

(6) Remove the speaker from the cab side inner
panel.
INSTALLATION
(1) Position the speaker to the cab side inner
panel.
(2) Reconnect the body wire harness connector to
the speaker connector receptacle.
(3) Position the speaker into the mounting hole in
the cab side inner panel.
(4) Install and tighten the two screws that secure
the speaker to the cab side inner panel. Tighten the
screws to 4 N´m (35 in. lbs.).
(5) Install the trim onto the rear cab side panel.
Refer to Body, Interior for the procedures.
(6) Reconnect the battery negative cable.
REAR DOOR SPEAKER
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the trim panel from the rear door.(3) Remove the two screws that secure the speaker
to the rear door inner panel (Fig. 22).
(4) Pull the speaker away from the mounting hole
in the rear door inner panel far enough to access the
door wire harness connector.
(5) Disconnect the door wire harness connector
from the speaker connector receptacle.
(6) Remove the speaker from the rear door inner
panel.
INSTALLATION
(1) Position the speaker to the rear door inner
panel.
(2) Reconnect the door wire harness connector to
the speaker connector receptacle.
(3) Position the speaker into the mounting hole in
the rear door inner panel.
(4) Install and tighten the two screws that secure
the speaker to the rear door inner panel. Tighten the
screws to 4 N´m (35 in. lbs.).
(5) Install the trim panel onto the rear door.
(6) Reconnect the battery negative cable.
Fig. 21 Rear Speaker Remove/Install - Club Cab
1 - WIRE HARNESS CONNECTOR
2 - CAB SIDE INNER PANEL
3 - SPEAKER
4 - SCREW
5 - CLIP
Fig. 22 Rear Door Speaker Remove/Install - Quad
Cab
1 - REAR DOOR INNER PANEL
2 - WIRE HARNESS CONNECTOR
3 - SPEAKER
4 - SCREW
5 - CLIP
BR/BEAUDIO 8A - 21
REAR CAB SIDE PANEL SPEAKER (Continued)

ELECTRONIC CONTROL MODULES
TABLE OF CONTENTS
page page
BODY CONTROL/CENTRAL TIMER MODULE
DESCRIPTION............................1
OPERATION.............................3
DIAGNOSIS AND TESTING..................4
CENTRAL TIMER MODULE................4
REMOVAL...............................5
INSTALLATION............................6
COMMUNICATION
DESCRIPTION............................6
OPERATION.............................7
DIAGNOSIS AND TESTING.................11
CCDDATABUS ........................11
CONTROLLER ANTILOCK BRAKE
DESCRIPTION...........................11
OPERATION.............................11REMOVAL..............................12
INSTALLATION...........................12
DATA LINK CONNECTOR
DESCRIPTION...........................12
OPERATION.............................12
ENGINE CONTROL MODULE
DESCRIPTION...........................13
OPERATION.............................13
REMOVAL..............................14
INSTALLATION...........................14
POWERTRAIN CONTROL MODULE
DESCRIPTION...........................14
OPERATION.............................17
REMOVAL..............................19
INSTALLATION...........................20
BODY CONTROL/CENTRAL
TIMER MODULE
DESCRIPTION
Three versions of the Central Timer Module (CTM)
are available on this vehicle, a base version (Fig. 1),a high-line version (Fig. 2), and a premium version.
Whichever version of the CTM the vehicle is
equipped with, it is concealed under the driver side
end of the instrument panel inboard of the instru-
ment panel steering column opening, where it is
secured with two screws to a stamped steel bracket
that is integral to the instrument panel armature.
The CTM is enclosed in a molded plastic housing
with one (base) or two (high-line/premium) integral
Fig. 1 Central Timer Module (Base)
1 - SCREWS
2 - BRACKET
3 - WIRE HARNESS CONNECTOR
4 - CENTRAL TIMER MODULE (BASE)
Fig. 2 Central Timer Module (High-Line/Premium)
1 - SCREWS
2 - BRACKET
3 - WIRE HARNESS CONNECTORS
4 - CENTRAL TIMER MODULE (HIGH-LINE/PREMIUM)
BR/BEELECTRONIC CONTROL MODULES 8E - 1

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)

CTM from the CTM connector receptacle(s). Check
the wire harness connectors and the CTM receptacles
for loose, corroded, or damaged terminals and pins. If
OK, go to Step 6. If not OK, repair as required.
(6) Check for continuity between the ground cir-
cuit cavity of the instrument panel wire harness con-
nector (Connector C1) for the CTM and a good
ground. For the high-line/premium version of the
CTM only, repeat the check between the ground cir-
cuit cavity of the instrument panel wire harness con-
nector (Connector C2) for the CTM and a good
ground. In each case, there should be continuity. If
OK, go to Step 7. If not OK, repair the open ground
circuit(s) to ground as required.
(7) Reconnect the battery negative cable. Check for
battery voltage at the fused B(+) circuit cavity of the
instrument panel wire harness connector (Connector
C1) for the CTM. If OK, go to Step 8. If not OK,
repair the open fused B(+) circuit between the CTM
and the JB as required.
(8) Turn the ignition switch to the On position.
Check for battery voltage at the fused ignition switch
output (st-run) circuit cavity (base version) or fused
ignition switch output (run-acc) circuit cavity (high-
line/premium version) of the instrument panel wire
harness connector (Connector C1) for the CTM. If OK
with a base version CTM, replace the faulty CTM. If
OK with a high-line/premium version CTM, use a
DRBIIItscan tool and the appropriate diagnostic
information to perform further diagnosis of the CTM.
If not OK, repair the open fused ignition switch out-
put circuit between the CTM and the JB.
REMOVAL
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
NOTE: Before replacing a high-line/premium version
Central Timer Module (CTM), use a DRBIIITscan
tool to retrieve the current settings for the CTM pro-
grammable features. Refer to the appropriate diag-
nostic information. These settings should be
duplicated in the replacement high-line/premiumCTM using the DRBIIITscan tool before returning
the vehicle to service.
(1) Disconnect and isolate the battery negative
cable.
(2) Remove the steering column opening cover
from the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - REMOVAL).
(3) Remove the two screws that secure the Central
Timer Module (CTM) to the bracket on the inboard
side of the instrument panel steering column opening
(Fig. 3) or (Fig. 4).
(4) Pull the CTM into the instrument panel steer-
ing column opening far enough to access the instru-
ment panel wire harness connector(s).
(5) Disconnect the instrument panel wire harness
connector(s) (one connector for the base version CTM,
two connectors for the high-line/premium version)
from the CTM connector receptacle(s).
(6) Remove the CTM from the instrument panel.
Fig. 3 Central Timer Module (Base) Remove/Install
1 - SCREWS
2 - BRACKET
3 - WIRE HARNESS CONNECTOR
4 - CENTRAL TIMER MODULE (BASE)
BR/BEELECTRONIC CONTROL MODULES 8E - 5
BODY CONTROL/CENTRAL TIMER MODULE (Continued)

INSTALLATION
WARNING: ON VEHICLES EQUIPPED WITH AIR-
BAGS, DISABLE THE AIRBAG SYSTEM BEFORE
ATTEMPTING ANY STEERING WHEEL, STEERING
COLUMN, OR INSTRUMENT PANEL COMPONENT
DIAGNOSIS OR SERVICE. DISCONNECT AND ISO-
LATE THE BATTERY NEGATIVE (GROUND) CABLE,
THEN WAIT TWO MINUTES FOR THE AIRBAG SYS-
TEM CAPACITOR TO DISCHARGE BEFORE PER-
FORMING FURTHER DIAGNOSIS OR SERVICE. THIS
IS THE ONLY SURE WAY TO DISABLE THE AIRBAG
SYSTEM. FAILURE TO TAKE THE PROPER PRE-
CAUTIONS COULD RESULT IN ACCIDENTAL AIR-
BAG DEPLOYMENT AND POSSIBLE PERSONAL
INJURY.
NOTE: Before replacing a high-line/premium version
Central Timer Module (CTM), use a DRBIIITscan
tool to retrieve the current settings for the CTM pro-
grammable features. Refer to the appropriate diag-
nostic information. These settings should be
duplicated in the replacement high-line/premium
CTM using the DRBIIITscan tool before returning
the vehicle to service.(1) Position the CTM to the inboard side of the
instrument panel steering column opening.
(2) Reconnect the instrument panel wire harness
connector(s) for the CTM (one connector for the base
version CTM, two connectors for the high-line/pre-
mium version) to the CTM connector receptacle(s)
(Fig. 3) or (Fig. 4).
(3) Position the CTM to the bracket on the inboard
side of the instrument panel steering column open-
ing.
(4) Install and tighten the two screws that secure
the CTM to the bracket on the inboard side of instru-
ment panel steering column opening. Tighten the
screws to 1.6 N´m (15 in. lbs.).
(5) Reinstall the steering column opening cover
onto the instrument panel. (Refer to 23 - BODY/IN-
STRUMENT PANEL/STEERING COLUMN OPEN-
ING COVER - INSTALLATION).
(6) Reconnect the battery negative cable.
COMMUNICATION
DESCRIPTION - CCD DATA BUS
The Chrysler Collision Detection (also referred to
as CCD or C2D ) data bus system is a multiplex sys-
tem used for vehicle communications on many
Chrysler Corporation vehicles. Within the context of
the CCD system, the term ªcollisionª refers to the
system's ability to avoid collisions of the electronic
data that enters the data bus from various electronic
control modules at approximately the same time.
Multiplexing is a system that enables the trans-
mission of several messages over a single channel or
circuit. Many Chrysler vehicles use this principle for
communication between the various microprocessor-
based electronic control modules.
Many of the electronic control modules in a vehicle
require information from the same sensing device. In
the past, if information from one sensing device was
required by several controllers, a wire from each con-
troller needed to be connected in parallel to that sen-
sor. In addition, each controller utilizing analog
sensors required an Analog/Digital (A/D) converter in
order to ªreadª these sensor inputs. Multiplexing
reduces wire harness complexity, sensor current
loads and controller hardware because each sensing
device is connected to only one controller, which
reads and distributes the sensor information to the
other controllers over the data bus. Also, because
each controller on the data bus can access the con-
troller sensor inputs to every other controller on the
data bus, more function and feature capabilities are
possible.
Fig. 4 Central Timer Module (High-Line/Premium)
Remove/Install
1 - SCREWS
2 - BRACKET
3 - WIRE HARNESS CONNECTORS
4 - CENTRAL TIMER MODULE (HIGH-LINE/PREMIUM)
8E - 6 ELECTRONIC CONTROL MODULESBR/BE
BODY CONTROL/CENTRAL TIMER MODULE (Continued)

ENGINE SYSTEMS
TABLE OF CONTENTS
page page
BATTERY SYSTEM......................... 1
CHARGING.............................. 27STARTING............................... 32
BATTERY SYSTEM
TABLE OF CONTENTS
page page
BATTERY SYSTEM
DESCRIPTION............................1
OPERATION.............................2
DIAGNOSIS AND TESTING..................2
BATTERY SYSTEM......................2
CLEANING...............................5
INSPECTION.............................5
SPECIFICATIONS.........................6
BATTERY
DESCRIPTION............................6
OPERATION.............................7
DIAGNOSIS AND TESTING..................7
BATTERY..............................7
STANDARD PROCEDURE...................8
CHECKING BATTERY ELECTROLYTE
LEVEL................................8
BATTERY CHARGING....................9
BUILT-IN INDICATOR TEST...............11
HYDROMETER TEST....................12
OPEN-CIRCUIT VOLTAGE TEST...........13
LOAD TEST...........................14IGNITION-OFF DRAW TEST...............15
REMOVAL..............................17
INSTALLATION...........................17
BATTERY HOLDDOWN
DESCRIPTION...........................18
OPERATION.............................18
REMOVAL..............................18
INSTALLATION...........................18
BATTERY CABLE
DESCRIPTION...........................19
OPERATION.............................20
DIAGNOSIS AND TESTING.................20
BATTERY CABLES......................20
REMOVAL..............................23
INSTALLATION...........................23
BATTERY TRAY
DESCRIPTION...........................24
OPERATION.............................25
REMOVAL..............................25
INSTALLATION...........................25
BATTERY SYSTEM
DESCRIPTION
A single 12-volt battery system is standard factory-
installed equipment on gasoline engine equipped
models. Models equipped with a diesel engine utilize
two 12-volt batteries connected in parallel. All of the
components of the battery system are located within
the engine compartment of the vehicle. The service
information for the battery system in this vehicle
covers the following related components, which are
covered in further detail elsewhere in this service
manual:²Battery- The storage battery provides a reli-
able means of storing a renewable source of electrical
energy within the vehicle.
²Battery Cable- The battery cables connect the
battery terminal posts to the vehicle electrical sys-
tem.
²Battery Holddown- The battery holddown
hardware secures the battery in the battery tray in
the engine compartment.
²Battery Tray- The battery tray provides a
secure mounting location in the vehicle for the bat-
tery and an anchor point for the battery holddown
hardware.
BR/BEENGINE SYSTEMS 8F - 1