Dodge 2004 Neon SX2 Diagnostic Manual page 18

identified as D25. The modules are wired in paral-
lel. Connections are made in the harness using
splices. The following modules are used on the PL:
• Airbag Control Module
• Left Side Impact Airbag Control Module
•
Right Side Impact Airbag Control Module
• Controller Antilock Brake
• Powertrain Control Module
• Radio (If equipped)
•
CD Changer (If equipped)
• Compass/Temperature Mirror (If equipped)
• Remote Keyless Entry Module (If equipped)
• Sentry Key Immobilizer Module (If equipped)
•
Mechanical Instrument Cluster
Each module provides its own bias and termina-
tion in order to transmit and receive messages. The
bus voltage is at zero volts when no modules are
transmitting and is pulled up to about seven and a
half volts when modules are transmitting.
The bus messages are transmitted at a rate
averaging 10800 bits per second. Since there is only
voltage present when the modules transmit and the
message length is only about 500 milliseconds, it is
ineffective to try and measure the bus activity with
a conventional voltmeter. The preferred method is
to use the DRBIII lab scope. The 12v square wave
selection on the 20-volt scale provides a good view of
the bus activity. Voltage on the bus should pulse
between zero and about seven and a half volts.
Refer to the following figure for some typical dis-
plays.
The PCI Bus failure modes are broken down into
two categories. Complete PCI Bus Communication
Failure and individual module no response. Causes
of a complete PCI Bus Communication Failure
include a short to ground or battery on the PCI
circuit. Individual module no response can be
caused by an open circuit at the module, or an open
battery or ground circuit to the affected module.
Symptoms of a complete PCI Bus Communication
Failure would include but are not limited to:
• All gauges on the EMIC stay at zero
•
All telltales on EMIC illuminate
• EMIC backlighting at full intensity
• No response received from any module on the PCI
bus (except PCM)
•
No start (if equipped with Sentry Key Immobi-
lizer)
Symptoms of Individual module failure could
include any one or more of the above. The difference
would be that at least one or more modules would
respond to the DRBIII .
Diagnosis starts with symptom identification. If a
complete PCI Bus Communication Failure is sus-
GENERAL INFORMATION
pected, begin by identifying which modules the
vehicle is equipped with and then attempt to get a
response from the modules with the DRBIII . If any
modules are responding, the failure is not related to
the total bus, but can be caused by one or more
modules PCI circuit or power supply and ground
circuits. The DRBIII may display "BUS +/- SIG-
NALS OPEN" OR "NO RESPONSE" to indicate a
communication problem. These same messages will
be displayed if the vehicle is not equipped with that
particular module. The CCD error message is a
default message used by the DRBIII and in no way
indicates whether or not the PCI bus is operational.
The message is only an indication that a module is
either not responding or the vehicle is not equipped.
NOTE: For 2004 model year, some vehicles
will integrate the
Module and Powertrain Control Module into a
single control module. This new module is
the Next Generation
DaimlerChrysler and will be referred to as the
Powertrain Control
Transmission Control Module is part of the
Powertrain Control Module.
Diagnostic procedures and DTC numbers are
some of the changes you will see which
reflect the new combined module technology.
The PCM will
connectors C1
C2-ORANGE, C3-WHITE, C4-GREEN), each
PCM connector will have 38 pins each. Two
new tools are used for probing and repairing
the New PCM connectors. A New tool to
release the pins from the PCM connectors
Miller #3638 is introduced, you must use the
Miller tool #3638 to release the connector
pins or harness and connector damage will
occur. Also a
connectors Miller #8815 is introduced, you
must use the Miller tool #8815 to probe the
PCM pins or harness and connector damage
will occur. There is also a new Verification
test and module replacment procedure for
the PCM.
11
Transmission Control
Controller
Module (PCM).
have four color
through C4, (C1-BLK,
New tool for probing
for
The
coded