Chrysler 300/300 Touring/300C, Dodge Magnum. Manual — part 393

REMOVAL

NOTE: A battery reconnect procedure must be per-
formed anytime the battery has been discon-
nected.

(Refer

to

8

-

ELECTRICAL/BATTERY

SYSTEM - STANDARD PROCEDURE).

1. Disconnect and isolate the battery negative cable.

2. Remove front door trim panel (Refer to 23 - BODY/

DOOR - FRONT/TRIM PANEL - REMOVAL).

3. Disconnect electrical harness connectors.

4. Remove mounting fasteners and module.

INSTALLATION

NOTE: A battery reconnect procedure must be per-
formed anytime the battery has been discon-
nected.

(Refer

to

8

-

ELECTRICAL/BATTERY

SYSTEM - STANDARD PROCEDURE).

1. Position module.

2. Install and tighten mounting fasteners.

3. Connect electrical harness connectors.

4. Install door trim panel (Refer to 23 - BODY/DOOR

- FRONT/TRIM PANEL - INSTALLATION).

5. Connect battery negative cable.

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ELECTRONIC CONTROL MODULES - SERVICE INFORMATION

LX

MODULE-ENGINE CONTROL

DESCRIPTION

The ECM is located in the left side of engine compart-
ment attached to the left inner fender behind the bat-
tery.

The electrical circuits at the ECM are split into two
separate wiring harnesses (vehicle and engine wiring
harness). The 58-pin connector is used for the vehicle
wiring harness. The 96-pin connector is for the engine
wiring harness.

The ECM connectors use slide locks. To remove the
ECM connectors, pull the slide locks sideways to the
end of their travel and lift the connectors.

A 32-bit microprocessor uses control algorithms to process the input signals and calculates the injected fuel based
on stored maps. The microprocessor triggers the driver stages for switching the output components. The ECM con-
tains the following data storage elements:

1. Flash EPROM—stores engine-specific curves, engine-management maps, and variant coding (engine and equip-

ment options).

2. EEPROM—stores immobilizer data, calibration and manufacturing data, adaptation values, operational faults and

variant coding.

3. RAM—stores variable data such as calculations data and input values.

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ELECTRONIC CONTROL MODULES - SERVICE INFORMATION

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OPERATION

The ECM has been programmed to monitor different
circuits of the diesel fuel injection system. This moni-
toring is called on-board diagnostics. Certain criteria
must be met for a diagnostic trouble code to be
entered into the ECM memory. The criteria may be a
range of: engine rpm, engine temperature, time or
other input signals to the ECM. If all of the criteria for
monitoring a system or circuit are met, and a problem
is sensed, then a DTC will be stored in the ECM
memory. It is possible that a DTC for a monitored cir-
cuit may not be entered into the ECM memory, even
though a malfunction has occurred. This may happen
when the monitoring criteria have not been met. The
ECM compares input signal voltages from each input
device with specifications (the established high and
low limits of the input range) that are programmed into
it for that device. If the input voltage is not within the
specifications and other trouble code criteria are met,
a DTC will be stored in the ECM memory.

ECM OPERATING MODES

As input signals to the ECM change, the ECM adjusts its response to the output devices. For example, the ECM
must calculate a different fuel quantity and fuel timing for engine idle condition than it would for a wide open throttle
condition. There are several different modes of operation that determine how the ECM responds to the various input
signals.

Ignition Switch On (Engine Off)

When the ignition is turned on, the ECM activates the glow plug relay for a time period that is determined by engine
coolant temperature, atmospheric temperature and battery voltage.

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ELECTRONIC CONTROL MODULES - SERVICE INFORMATION

LX

Engine Start-Up Mode

The ECM uses the engine temperature sensor and the crankshaft position sensor (engine speed) inputs to deter-
mine fuel injection quantity.

Normal Driving Modes

Engine idle, warm-up, acceleration, deceleration and wide open throttle modes are controlled based on all of the
sensor inputs to the ECM. The ECM uses these sensor inputs to adjust fuel quantity and fuel injector timing.

Limp-In Mode

If there is a fault detected with the accelerator pedal position sensor, the ECM will set the engine speed at 1100
RPM.

Overspeed Detection Mode

If the ECM detects engine RPM that exceeds 5200 RPM, the ECM will set a DTC in memory and illuminate the MIL
until the DTC is cleared.

After-Run Mode

The ECM transfers RAM information to ROM and performs an Input/Output state check.

MONITORED CIRCUITS

The ECM is able to monitor and identify most driveability related trouble conditions. Some circuits are directly mon-
itored through ECM feedback circuitry. In addition, the ECM monitors the voltage state of some circuits and com-
pares those states with expected values. Other systems are monitored indirectly when the ECM conducts a
rationality test to identify problems. Although most subsytems of the engine control module are either directly or
indirectly monitored, there may be occasions when diagnostic trouble codes are not immediately identified. For a
trouble code to set, a specific set of conditions must occur and unless these conditions occur, a DTC will not set.

DIAGNOSTIC TROUBLE CODES

Each diagnostic trouble code (DTC) is diagnosed by following a specific procedure. The diagnostic test procedure
contains step-by-step instruction for determining the cause of the DTC as well as no trouble code problems. Refer
to the appropriate Diesel Powertrain Diagnostic Manual for more information.

HARD CODE

A DTC that comes back within one cycle of the ignition key is a hard code. This means that the problem is current
every time the ECM/SKIM checks that circuit or function. Procedures in this manual verify if the DTC is a hard code
at the beginning of each test. When the fault is not a hard code, an intermittent test must be performed. NOTE: If
the DRBIII

T

displays faults for multiple components (i.e. ECT, VSS, IAT sensors) identify and check the shared cir-

cuits for possible problems before continuing (i.e. sensor grounds or 5-volt supply circuits). Refer to the appropriate
schematic to identify shared circuits. Refer to the appropriate Diesel Powertrain Diagnostic Manual for more infor-
mation.

INTERMITTENT CODE

A DTC that is not current every time the ECM/SKIM checks the circuit or function is an intermittent code. Most
intermittent DTCs are caused by wiring or connector problems. Problems that come and go like this are the most
difficult to diagnose; they must be looked for under specific conditions that cause them. NOTE: Electromagnetic
(radio) interference can cause an intermittent system malfunction. This interference can interrupt communica-
tion between the ignition key transponder and the SKIM. The following checks may assist you in identifying a pos-
sible intermittent problem:

•

Visually inspect the related wire harness connectors. Look for broken, bent, pushed out or corroded terminals.

•

Visually inspect the related wire harness. Look for chafed, pierced or partially broken wire.

•

Refer to hotlines or technical service bulletins that may apply.

Refer to the appropriate Diesel Powertrain Diagnostic Manual for more information.

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