Dodge Ram 2004, Service Manual

Page: 15 / 642

1.0 INTRODUCTION
The procedures contained in this manual include
all the specifications, instructions and graphics
needed to diagnose 2004 body system problems. The
diagnostics in this manual are based on the failure
condition or symptom being present at the time of
diagnosis.
Please follow the recommendations below when
choosing your diagnostic path.
1. First make sure the DRBIII
t
is communicating
with the appropriate modules; i.e., if the
DRBIII
t
displays a “No Response” or a “Bus
6
Signals Open” condition, you must diagnose that
first.
2. Read DTC’s (diagnostic trouble codes) with the
DRBIII
t
.
3. If no DTC’s are present, identify the customer
complaint.
4. Once the DTC or customer complaint is identi-
fied, locate the matching test in the Table of
Contents and begin to diagnose the symptom.
All component location views are in Section 8.0. All
connector pinouts are in Section 9.0. All schematics
are in Section 10.0.
An * placed before the symptom description indi-
cates a customer complaint.
When repairs are required, refer to the appropri-
ate service information for the proper removal and
repair procedure.
Diagnostic procedures change every year. New
diagnostic systems may be added: carryover sys-
tems may be enhanced. READ THIS MANUAL
BEFORE TRYING TO DIAGNOSE A VEHICLE
DIAGNOSTIC TROUBLE CODE. It is recom-
mended that you review the entire manual to be-
come familiar with all the new and changed diag-
nostic procedures.
This book reflects many suggested changes from
readers of past issues. After using this book, if you
have any comments or suggestions, please fill out
the form in the back of this book and mail it back to
us.
1.1 SYSTEM COVERAGE
This diagnostic procedures manual covers all
2004 DR Ram Truck vehicles.
1.2 SIX-STEP TROUBLESHOOTING
PROCEDURE
Diagnosis of the body system is done in six basic
steps:
•
verification of complaint
• verification of any related symptoms
• symptom analysis
• problem isolation
• repair of isolated problem
•
verification of proper operation
2.0 IDENTIFICATION OF
SYSTEM
The vehicle systems that are part of the “body”
system are:
• Airbag
• Audio (with amplifier on premium systems)
• Chime
• Communication
•
Door Ajar System
• Electrically heated system
•
Exterior lighting
• Heating and A/C
•
Horn
• Instrument Cluster
• Interior Lighting
• Memory Seat
• Overhead Console
• Power Door Lock/RKE
• Power windows
•
Telecommunications (hands free phone)
• Vehicle theft security system (VTSS)
•
Windshield Wiper and Washer
3.0 SYSTEM DESCRIPTION AND
FUNCTIONAL OPERATION
The body system on the 2004 DR consists of a
combination of modules that communicate over the
PCI bus (Programmable Communication Interface
multiplex system). Through the PCI bus, informa-
tion about the operation of vehicle components and
circuits is relayed quickly to the appropriate mod-
ule(s). All modules receive all the information trans-
mitted on the bus even though a module may not
require all information to perform its function. It
will only respond to messages “addressed” to it
through binary coding process. This method of data
transmission significantly reduces the complexity
of the wiring in the vehicle and the size of wiring
harnesses. All of the information about the func-
tioning of all the systems is organized, controlled,
and communicated by the PCI bus, which is de-
scribed in the communication section of this general
information.
1
GENERAL INFORMATION