Chrysler Concorde 1993, Service Manual, Page: 513 / 820

SEQUENTIAL MULTI-PORT FUEL INJECTION—SYSTEM OPERATION
INDEX
page page
5 Volt Supply—PCM Output . . . . . . . . . . . . . . . . . 32
8-Volt Supply—PCM OUtput . . . . . . . . . . . . . . . . . 32
Air Conditioning Compressor Clutch Relay—
PCM Output . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Air Conditioning Pressure Transducer—PCM Input . 23
ASD Sense—PCM Input . . . . . . . . . . . . . . . . . . . . 23
Auto Shutdown And Fuel Pump Relays—
PCM Output . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Battery Voltage—PCM Input . . . . . . . . . . . . . . . . . 23
Brake Switch—PCM Input . . . . . . . . . . . . . . . . . . . 23
Camshaft Position Sensor—PCM Input . . . . . . . . . 23
Charge Air Temperature Sensor—PCM Input
. . . . 23
Chrysler Collision Detection (CCD) Bus . . . . . . . . 20
Crankshaft Position Sensor—PCM Input . . . . . . . . 25
Data Link Connector—PCM Output . . . . . . . . . . . . 28
Duty Cycle EVAP Purge Solenoid—PCM Output . . 29
EGR Solenoid—PCM Output
. . . . . . . . . . . . . . . . 29
Engine Coolant Temperature Sensor—PCM Input . 25
Fuel Injectors—PCM Output . . . . . . . . . . . . . . . . . 29
Fuel Pressure Regulator . . . . . . . . . . . . . . . . . . . . 35
General Information
. . . . . . . . . . . . . . . . . . . . . . . 20
Generator Field—PCM Output . . . . . . . . . . . . . . . 30
Heated Oxygen Sensors—PCM Input . . . . . . . . . . 26
Idle Air Control Motor—PCM Output . . . . . . . . . . . 30
Ignition Coil—PCM Output
. . . . . . . . . . . . . . . . . . 30
Ignition Sense—PCM Input . . . . . . . . . . . . . . . . . . 26
Knock Sensors (3.5L Engine)—PCM Input
. . . . . . 25
Malfunction Indicator (Check Engine) Lamp—
PCM Output . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
Manifold Absolute Pressure Sensor—PCM Input . . 26
Manifold Tuning Valve (MTV) Solenoid (3.5L)—
PCM Output . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Modes Of Operation . . . . . . . . . . . . . . . . . . . . . . . 32
Powertrain Control Module
. . . . . . . . . . . . . . . . . . 21
Radiator Fan Relays—PCM Output . . . . . . . . . . . . 32
SCI Circuits
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Sensor Return—PCM Input . . . . . . . . . . . . . . . . . . 27
Speed Control—PCM Input . . . . . . . . . . . . . . . . . . 27
Speed Control Relay—PCM Output
. . . . . . . . . . . 32
Speed Control Servos—PCM Output . . . . . . . . . . . 32
System Diagnosis . . . . . . . . . . . . . . . . . . . . . . . . . 20
Tachometer—PCM Output
. . . . . . . . . . . . . . . . . . 32
Throttle Bodies—3.5L Engine . . . . . . . . . . . . . . . . 34
Throttle Body—3.3L Engine . . . . . . . . . . . . . . . . . 34
Throttle Position Sensor—PCM Input . . . . . . . . . . 27
Transmission Control Module . . . . . . . . . . . . . . . . 22
GENERAL INFORMATION
The 3.3L and 3.5L engines use a sequential multi-
port electronic fuel injection system (Fig. 1). The
powertrain control module (PCM) operates the elec-
tronic fuel injection system. The PCM provides pre-
cise air/fuel ratios and ignition timing for all driving
conditions.
The PCM regulates the air-fuel ratio, ignition coil
dwell and idle speed. The PCM also operates the
high speed and low speed cooling fans, charging sys-
tem, speed control system and various emission con-
trol devices.
Various sensors and switches provide inputs to the
PCM. The PCM converts all inputs into signals and
regulates various systems based on the inputs. The
PCM adjusts the systems it controls to meet chang-
ing operating conditions.
Fuel is injected into the intake port above the in-
take valve in precise metered amounts through elec-
trically operated injectors. The 3.5L engine use
bottom feed injectors while the 3.3L engine uses top
feed injectors. The PCM operates the injectors in a
specific sequence. The PCM maintains an air fuel ra-
tio of 14.7 parts air to 1 part fuel by constantly ad-
justing injector pulse width. Injector pulse width
refers to the amount of time an injector operates.
The PCM adjusts injector pulse width by opening
and closing the ground path to the injectors. Engine
RPM (speed) and manifold absolute pressure (air
density) are the primary inputs that determine injec-
tor pulse width.
SYSTEM DIAGNOSIS
The powertrain control module (PCM) can test
many of its own input and output circuits. If the
PCM senses a fault in a major system, the PCM
stores a diagnostic trouble code in memory.
Technicians can display stored diagnostic trouble
codes by two different methods. The first is to cycle
the ignition switch On - Off - On - Off - On within 5
seconds. Then count the number of times the mal-
function indicator lamp (check engine lamp) on the
instrument panel flashes on and off. The number of
flashes represents the trouble code. There is a slight
pause between the flashes representing the first and
second digits of the code. Longer pauses separate in-
dividual trouble codes.
The second method of reading diagnostic trouble
codes uses the DRBII scan tool. For diagnostic trou-
ble code information, refer to the On-Board Diagnos-
tics section in this group.
CHRYSLER COLLISION DETECTION (CCD) BUS
Various modules exchange information through a
communications port called the CCD Bus. The pow-
ertrain control module (PCM) transmits the Malfunc-
tion Indicator Lamp (Check Engine) On/Off signal
and engine RPM on the CCD Bus. PCM receives the
Air Conditioning select input and speed control en-
gage inputs over the CCD Bus. The PCM also re-
ceives the air conditioning evaporator temperature
signal from the CCD Bus.
14 - 20 FUEL SYSTEMS