air filter CHEVROLET DYNASTY 1993 Owner's Manual

(3) Inspect quick connect fittings for damage, re-
place if necessary Refer to Fuel System, Group 14 for
procedure. Lube tube with clean 30w engine oil, Con-
nect fuel supply and return hoses to chassis tube as-
sembly. Check connection by pulling on connector to
insure it locked into position (Fig. 9). (4) Connect Fuel Injector (Fig. 8), and Charge
Temperature Sensor wiring connectors (Fig. 7).
INTAKE MANIFOLD
(5) Connect Automatic Idle Speed (AIS) and Throt-
tle Position Sensor (TPS) wiring connectors (Fig. 6). (6) Connect vacuum hoses to throttle body (Fig. 5).
(7) Install intercooler to throttle body hose and
clamp. Torque clamp to 3 N Im (30 in. lbs.) (Fig. 5). (8) Connect accelerator and speed control cables
(Fig. 4). (9) Install DIS ignition coil pack. Tighten fasteners
to 12 N Im (105 in. lbs.) torque (Fig. 3).
(10) Install upper radiator hose and spring clamps
(Fig. 2). Fill cooling system, Refer to Cooling System,
Group 7. (11) Install fresh air duct to air filter housing. In-
stall inlet hose assembly to Intercooler. Tighten
clamp to 3 N Im (30 in. lbs.) torque (Fig. 1).
(12) Connect negative battery cable.
(13) With the DRBII Scan Tool use ASD Fuel Sys-
tem Test to pressurize system to check for leaks.
Fig. 5 Intercooler to Throttle Body Hose
Fig. 6 Automatic Idle Speed (AIS) Motor and
Throttle Position Sensor (TPS) Wiring Connectors
Fig. 7 Intake Manifold Electrical and Vacuum Hose Connections
Fig. 8 Camshaft Sensor and Fuel Injectors WiringConnectors
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 11

The exhaust manifolds are made of ductile cast
iron with the front bank and rear bank independent
of each other. The exhaust from the front bank ex-
haust manifold is led through on exhaust crossover
pipe to be combined with the rear bank exhaust at
the exhaust outlet to the exhaust pipe (Fig. 2).
INTAKE PLENUM/MANIFOLD
REMOVAL
(1) Perform fuel system pressure release procedure
(before attempting any repairs). (2) Disconnect negative battery cable. Drain cooling
system. See Cooling System, Group 7. (3) Remove air cleaner to throttle body hose (Fig. 3).
FUEL SYSTEM PRESSURE RELEASE PROCE-DURE
The MPI fuel system is under a constant pres-
sure of about 330 kPa (48 psi). Before servicing
the fuel pump, fuel lines, fuel filter, throttle body
or fuel injector, the fuel system pressure must be
released .
(a) Loosen fuel filler cap to release fuel tank pres-
sure. (b) Disconnect injector wiring harness from engine
harness. (c) Connect a jumper wire to ground terminal
Number 1 of the injector harness (Fig. 1) to engine
ground. (d) Connect a jumper wire to the positive terminal
Number 2 of the injector harness (Fig. 1) and touch
the battery positive post for no longer than 5 seconds.
This releases system pressure.
Fig. 1 Injector Harness Connector
Fig. 2 Intake and Exhaust ManifoldsÐ 3.0L Engine
11 - 14 EXHAUST SYSTEM AND INTAKE MANIFOLD Ä

(2) Attach exhaust pipe to exhaust manifold and
tighten shoulder bolt to 28 N Im (250 in. lbs.)
(3) Attach crossover pipe to exhaust manifold and
tighten bolt to 69 N Im (51 ft. lbs.)
(4) Connect heated oxygen sensor lead (Fig. 18).
(5) Install front exhaust manifold and attach ex-
haust crossover. (6) Install front manifold heat shield and tighten
attaching screws to 15 N Im (130 in. lbs.) (Fig. 2).
INTAKE/EXHAUST MANIFOLD SERVICEÐ3.3/3.8L
ENGINES
INTAKE MANIFOLD
REMOVAL
(1) Perform fuel system pressure release procedure,
Before attempting any repairs. (2) Disconnect negative battery cable. Drain cool-
ing system. Refer to Cooling System, Group 7.
FUEL SYSTEM PRESSURE RELEASE PROCE- DURE
The MPI fuel system is under a constant pressure
of about 330 kPa (48 psi). Before servicing the fuel
pump, fuel lines, fuel filter, throttle body or fuel
injector, the fuel system pressure must be released.
(a) Loosen fuel filler cap to release fuel tank pres-
sure. (b) Disconnect injector wiring harness from engine
harness.
(c) Connect a jumper wire to ground terminal Num-
ber 1 of the injector harness (Fig. 1) to engine ground.
(d) Connect a jumper wire to the positive terminal
Number 2 of the injector harness (Fig. 1) and touch
the battery positive post for no longer than 5 seconds.
This releases system pressure. (e) Remove jumper wires.
(f) Continue fuel system service.
(3) Remove air cleaner to throttle body hose assem-
bly (Fig. 2).
Fig. 20 Check Exhaust Manifold Mounting Surface
Fig. 21 Identify Exhaust Manifold Gaskets
Fig. 1 Injector Harness Connectors
Fig. 2 Throttle Body AssemblyÐ3.3/3.8L Engines
Ä EXHAUST SYSTEM AND INTAKE MANIFOLD 11 - 19

once the system has entered closed loop. Refer to
Modes of Operation in this section for an explanation
of closed loop operation.
NON-MONITORED CIRCUITS
The PCM does not monitor the following circuits,
systems and conditions that could have malfunctions
that result in driveability problems. Diagnostic trou-
ble codes may not be displayed for these conditions.
However, problems with these systems may cause di-
agnostic trouble codes to be displayed for other sys-
tems. For example, a fuel pressure problem will not
register a fault directly, but could cause a rich or
lean condition. This could cause an oxygen sensor
fault to be stored in the PCM. Fuel Pressure - Fuel pressure is controlled by the
fuel pressure regulator. The PCM cannot detect a
clogged fuel pump inlet filter, clogged in-line fuel fil-
ter, or a pinched fuel supply or return line. However,
these could result in a rich or lean condition causing
an oxygen sensor fault. Secondary Ignition Circuit - The PCM cannot
detect an inoperative ignition coil, fouled or worn
spark plugs, ignition cross firing, or open spark plug
cables. Engine Timing - The PCM cannot detect an incor-
rectly indexed timing chain, camshaft sprocket and
crankshaft sprocket. The PCM also cannot detect an
incorrectly indexed distributor. However, these could
result in a rich or lean condition causing an oxygen
sensor fault to be stored in the PCM. Cylinder Compression - The PCM cannot detect
uneven, low, or high engine cylinder compression. Exhaust System
- The PCM cannot detect a
plugged, restricted or leaking exhaust system. Fuel Injector Malfunctions - The PCM cannot
determine if the fuel injector is clogged, the pintle is
sticking or the wrong injector is installed. However,
these could result in a rich or lean condition causing
an oxygen sensor fault to be stored in the PCM. Excessive Oil Consumption - Although the PCM
monitors the exhaust stream oxygen content through
the oxygen sensor when the system is in closed loop,
it cannot determine excessive oil consumption. Throttle Body Air Flow - The PCM cannot detect
a clogged or restricted air cleaner inlet or filter ele-
ment. Evaporative System - The PCM will not detect a
restricted, plugged or loaded evaporative purge can-
ister. Vacuum Assist - Leaks or restrictions in the vac-
uum circuits of vacuum assisted engine control sys-
tem devices are not monitored by the PCM. However,
these could result in a MAP sensor fault being stored
in the PCM. PCM System Ground - The PCM cannot deter-
mine a poor system ground. However, a diagnostic
trouble code may be generated as a result of this con-
dition. PCM Connector Engagement - The PCM cannot
determine spread or damaged connector pins. How-
ever, a diagnostic trouble code may be generated as a
result of this condition.
HIGH AND LOW LIMITS
The powertrain control module (PCM) compares in-
put signal voltages from each input device with es-
tablished high and low limits that are programmed
into it for that device. If the input voltage is not
within specifications and other diagnostic trouble
code criteria are met, a diagnostic trouble code will
be stored in memory. Other diagnostic trouble code
criteria might include engine RPM limits or input
voltages from other sensors or switches that must be
present before a fault condition can be verified.
DIAGNOSTIC TROUBLE CODE DESCRIPTION
When a diagnostic trouble code appears, it indi-
cates the powertrain control module (PCM) has rec-
ognized an abnormal condition in the system.
Diagnostic trouble codes can be obtained from the
malfunction indicator lamp (instrument panel Check
Engine lamp) on the Instrument Panel or from the
DRBII scan tool. Diagnostic trouble codes indicate
the results of a failure but do not identify the failed
component directly.
Fig. 3 Data Link Connector LocationÐAG and AJ Vehicles
14 - 42 FUEL SYSTEMS Ä

2.2L/2.5L SINGLE POINT FUEL INJECTIONÐSERVICE PROCEDURES INDEX
page page
Canister Purge Solenoid ................... 53
Electric Exhaust Gas Recirculation Transducer (EET) Service ............................... 53
Fuel Fitting ............................. 50
Fuel Injector ............................ 51
Fuel Lines and Hoses ..................... 48
Fuel Pressure Regulator ................... 51 Fuel System Pressure Release Procedure
...... 48
Heated Oxygen Sensor (O
2Sensor) .......... 54
Idle Air Control Motor ..................... 53
Manifold Absolute Pressure Sensor ........... 53
PCM Service ............................ 54
Throttle Body ............................ 48
Throttle Position Sensor ................... 52
FUEL LINES AND HOSES
Perform the Fuel System Pressure Relief Procedure
before servicing the fuel system. The procedure must
be done to bleed fuel pressure from the system before
removing clamps or hoses. Use care when removing fuel hoses to prevent dam-
age to hose or hose nipple. Always use new hose
clamps, of the correct type, during reassembly. Tighten
hose clamps to 1 N Im (10 in. lbs.) torque. Do not use
aviation style clamps on this system or hose
damage may result.
FUEL SYSTEM PRESSURE RELEASE PROCEDURE
CAUTION: Before servicing the fuel pump, fuel lines,
fuel filter, throttle body, or fuel injector, release fuel
system pressure.
(1) Loosen fuel filler cap to release fuel tank pres-
sure. (2) Disconnect injector wiring harness connector at
edge of throttle body (Fig. 1). (3) Connect a jumper wire between terminal Num-
ber 1 of the injector harness and engine ground. (4) Connect a jumper wire to the positive terminal
Number 2 of the injector harness and touch the battery
positive post for no longer than 5 seconds . This
releases system pressure. (5) Remove jumper wires.
(6) Continue fuel system service.
THROTTLE BODY
CAUTION: The fuel system is under a constant pres-
sure of 270 kPa (39 psi). When servicing the fuel
portion of the throttle body, release fuel pressure
before disconnecting any tubes. Refer to the fuel
pressure release procedure.
Always reassemble throttle body components with
new O-rings and seals where applicable. Never use
silicone lubricants on O-rings or seals, damage may
result. Use care when removing fuel tubes to prevent
damage to quick connect fittings or tube ends. Refer to Fuel Hoses, Clamps, and Quick Connect Fittings
in the Fuel Delivery Section of this Group.
REMOVAL
(1) Remove air cleaner (Fig. 2).
(2) Perform fuel system pressure release procedure.
(3) Disconnect negative battery cable.
(4) Disconnect vacuum hoses and electrical connec-
tors (Fig. 3).
Fig. 1 Injector Harness Connector
Fig. 2 Throttle Body and Air Cleaner Assembly
14 - 48 FUEL SYSTEMS Ä

(2) Remove sensor using Tool C-4907 (Fig. 21).
Slightly tightening the sensor can ease removal. When the sensor is removed, the exhaust manifold
threads must be cleaned with an 18 mm X 1.5 + 6E
tap. If the same sensor is to be reinstalled, the sensor
threads must be coated with an anti-seize compound
such as Loctite 771-64 or equivalent. New sensors
are packaged with compound on the threads and do
not require additional compound. The sensor must be
tightened to 27 N Im (20 ft. lbs.) torque.
2.5L FLEXIBLE FUEL MULTI-PORT FUEL INJECTIONÐSYSTEM OPERATION
INDEX
page page
Air Conditioning (A/C) Clutch RelayÐPCM Output.61
Air Conditioning Switch SenseÐPCM Input ..... 57
Auto Shutdown (ASD) Relay and Fuel Pump RelayÐPCM Output ..................... 61
Battery VoltageÐPCM Input ................ 58
Brake SwitchÐPCM Input .................. 58
Camshaft Position SensorÐPCM Input ........ 58
CCD BUS .............................. 57
Data Link ConnectorÐPCM Output ........... 62
Duty Cycle Evap Purge SolenoidÐPCM Output . 61
Engine Coolant Temperature SensorÐPCM Input . 58
Fuel InjectorÐPCM Output ................. 62
Fuel Injectors and Fuel Rail Assembly ......... 65
Fuel Pressure Regulator ................... 65
Fuel Supply Circuit ....................... 65
General Information ....................... 55
Generator FieldÐPCM Output ............... 62
Heated Oxygen Sensor (O
2Sensor)ÐPCM Input . 59
Identifying Flexible Fuel Components .......... 55
Idle Air Control MotorÐPCM Output .......... 62 Ignition CoilÐPCM Output
.................. 62
Malfunction Indicator (Check Engine) LampÐPCM Output ............................... 62
Manifold Absolute Pressure (MAP) SensorÐPCM Input ................................ 58
Methanol Concentration SensorÐPCM Input .... 59
Modes of Operation ....................... 63
Powertrain Control Module ................. 57
Radiator Fan RelayÐPCM Output ............ 63
Speed Control SolenoidsÐPCM Output ........ 63
Speed ControlÐPCM Input ................. 60
System Diagnosis ........................ 56
System Operation ........................ 56
TachometerÐPCM Output .................. 63
Throttle Body ............................ 65
Throttle Position Sensor (TPS)ÐPCM Input ..... 60
Torque Converter Clutch SolenoidÐPCM Output . 63
Transaxle Park/Neutral SwitchÐPCM Input ..... 60
Vehicle Speed SensorÐPCM Input ........... 60
GENERAL INFORMATION
In this model year Chrysler began producing AA-
Body vehicles designed to operate on a mixture of
gasoline and methanol. These automobiles are re-
ferred to as Flexible Fuel vehicles. Fuel system com-
ponents designed for use in flexible fuel vehicles are
referred to as Methanol Compatible. Flexible fuel vehicles can operate on a mixture of
up to 85 percent methanol, 15 percent unleaded gas-
oline. These vehicles also operate on mixtures con-
taining a lower percentage of methanol or just pure
unleaded gasoline.
IDENTIFYING FLEXIBLE FUEL COMPONENTS
Flexible Fuel vehicles have unique methanol com-
patible fuel system components. Chrysler identifies
methanol compatible components that could be phys-
ically interchanged with gasoline only parts by color-
ing them green or applying a green label or tag to
them. Even though they may appear physically iden- tical, components for gasoline only AA-body vehicles
must not be used on flexible fuel vehicles.
FLEXIBLE FUEL COMPONENTS
The fuel system of flexible fuel AA-body vehicles
have the following unique methanol compatible com-
ponents.
² Duty Cycle EVAP Purge Solenoid
² Fuel pump module
² Fuel level sensor
² Fuel gauge (gauge cluster).
² Fuel tank
² Fuel pressure regulator (including O-rings)
² Fuel rail
² Fuel injectors (including O-rings)
² Fuel tubes
² Fuel filter
² EVAP canister
² Fuel filler cap
² Fuel filler tube
Fig. 21 Oxygen Sensor Socket
Ä FUEL SYSTEMS 14 - 55

The exhaust gas oxygen content input is not ac-
cepted by the PCM during wide open throttle opera-
tion. The PCM will enrichen the air/fuel ratio to
increase performance and compensate for increased
combustion chamber temperature. The PCM determines the methanol content of the
fuel from the methanol concentration sensor input.
IGNITION SWITCH OFF MODE
This is an OPEN LOOP mode. When the ignition
switch is turned to the OFF position, the following
occurs:
² All outputs are turned off.
² No inputs are monitored.
² The PCM shuts down.
THROTTLE BODY
The throttle body houses the throttle position sen-
sor (TPS) and the idle air control motor (Fig. 15). Air
flow through the throttle body is controlled by a ca-
ble operated throttle blade at the base of the throttle
body.
FUEL SUPPLY CIRCUIT
Fuel is pumped to the fuel rail by an electrical
pump in the fuel tank. A filter, attached to the pump
inlet, prevents water and other contaminants from
entering the fuel supply circuit. The vacuum assisted fuel pressure regulator keeps
fuel pressure at 380 kPa (55 psi). The regulator uses
intake manifold pressure at the vacuum tee as a ref-
erence.
FUEL INJECTORS AND FUEL RAIL ASSEMBLY
Four fuel injectors are retained in the fuel rail by
lock rings (Fig. 16). The fuel injectors and rail bolt in
position with the injectors inserted into recessed
holes in the intake manifold.
FUEL PRESSURE REGULATOR
The pressure regulator is located downstream of
the fuel injector on the fuel rail (Fig. 17). The regu-
lator maintains constant 380 kPa (55 PSI) fuel pres-
sure across the fuel injector tip. The regulator has a spring loaded rubber dia-
phragm that uncovers a fuel return port. When the
fuel pump operates, fuel flows past the injector into
the regulator. Fuel is restricted from flowing any fur-
ther by the blocked return port. When fuel pressure
reaches 380 kPa (55 PSI), it pushes on the dia-
phragm, compresses the spring, and uncovers the
fuel return port. The diaphragm and spring continu-
ally move from an open to closed position keeping
the fuel pressure consistent.
Fig. 15 Throttle Body
Fig. 16 Fuel Supply System
Fig. 17 Fuel Pressure Regulator
Ä FUEL SYSTEMS 14 - 65

the PCM to store diagnostic trouble codes for other
systems. For example, a fuel pressure problem will not
register a fault directly, but could cause a rich or lean
condition. This could cause the PCM to store an oxygen
sensor diagnostic trouble code. Fuel Pressure - The vacuum assisted fuel pressure
regulator controls fuel system pressure. The PCM
cannot detect a clogged fuel pump inlet filter, clogged
in-line fuel filter, stuck open regulator, or a pinched
fuel supply or return line. However, these could result
in a rich or lean condition causing the PCM to store an
oxygen sensor diagnostic trouble code. Secondary Ignition Circuit - The PCM cannot
detect an inoperative ignition coil, fouled or worn spark
plugs, ignition cross firing, or open spark plug cables. Engine Timing - The PCM cannot detect an incor-
rectly indexed timing belt, camshaft sprocket and
crankshaft sprocket. However, these could result in a
rich or lean condition causing the PCM to store an
oxygen sensor diagnostic trouble code. Cylinder Compression - The PCM cannot detect
uneven, low, or high engine cylinder compression. Exhaust System - The PCM cannot detect a
plugged, restricted or leaking exhaust system. Fuel Injector Mechanical Malfunctions - The
PCM cannot determine if a fuel injector is clogged, the
needle is sticking or if the wrong injector is installed.
However, these could result in a rich or lean condition
causing the PCM to store an oxygen sensor diagnostic
trouble code. Excessive Oil Consumption - Although the PCM
monitors exhaust stream oxygen content when the
system is in closed loop, it cannot determine excessive
oil consumption. Throttle Body Air Flow - The PCM cannot detect a
clogged or restricted air cleaner inlet or filter element. Evaporative System - The PCM cannot detect a
disconnected (open vacuum line) restricted, plugged or
loaded evaporative purge canister. Vacuum Assist - The PCM cannot detect leaks or
restrictions in the vacuum circuits of vacuum assisted
engine control system devices. However, these could
cause the PCM to store a MAP sensor diagnostic
trouble code and cause a high idle condition. PCM System Ground - The PCM cannot determine
a poor system ground. However, one or more diagnostic
trouble codes may be generated as a result of this
condition. PCM Connector Engagement - The PCM may not
be able to determine spread or damaged connector
pins. However, it might store diagnostic trouble codes
as a result of spread connector pins.HIGH AND LOW LIMITS
The PCM compares input signal voltages from each
input device with established high and low limits for the
device. If the input voltage is not within limits and other
criteria are met, the PCM stores a diagnostic trouble code
in memory. Other diagnostic trouble code criteria might
include engine RPM limits or input voltages from other
sensors or switches that must be present before verifying
a diagnostic trouble code condition.
DIAGNOSTIC TROUBLE CODES
A diagnostic trouble code indicates the powertrain
control module (PCM) has recognized an abnormal
condition in the system. Abnormal conditions are usu-
ally shorted or open circuits.
The technician can display diagnostic trouble codes in
two ways. The first way is to cycle the ignition switch and
count the number of times the malfunction indicator lamp
(check engine lamp on the instrument panel) flashes on
and off. The DRBII scan tool provides the second method
of displaying diagnostic trouble codes. Diagnostic trouble
codes indicate the results of a circuit failure, but do not
directly identify the failed component.
For a list of Diagnostic Trouble Codes, refer to
the charts at the end of this section.
OBTAINING DIAGNOSTIC TROUBLE CODES
USING DRBII SCAN TOOL
WARNING: APPLY PARKING BRAKE AND/OR BLOCK
WHEELS BEFORE PERFORMING ANY TEST ON AN
OPERATING ENGINE. (1) Connect DRBII scan tool to the data link (diag-
nostic) connector located in the engine compartment,
next to the PCM (Fig. 1). (2) If possible, start the engine and cycle the A/C
switch if applicable. Shut off the engine. (3)
Turn the ignition switch on, access Read Fault
Screen. Record all the diagnostic trouble codes shown on
the DRBII scan tool. [Observe the malfunction indicator
lamp (check engine lamp) on the instrument panel. The
lamp should light for 2 seconds then go out (bulb check)].
To erase diagnostic trouble codes, use the Erase
Trouble Code data screen on the DRBII scan tool.
USING THE MALFUNCTION INDICATOR LAMP (1) Cycle the ignition key On - Off - On - Off - On
within 5 seconds. (2) Count the number of times the malfunction indi-
cator 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 be-
Ä FUEL SYSTEMS 14 - 71

2.5L FLEXIBLE FUEL MULTI-PORT FUEL INJECTIONÐSERVICE PROCEDURES INDEX
page page
Fuel Injector ............................. 80
Fuel Injector Rail Assembly ................. 79
Fuel Pressure Regulator .................... 81
Fuel System Pressure Release Procedure ...... 78
General Information ....................... 77
Heated Oxygen Sensor (O
2Sensor) ........... 82
Identifying Flexible Fuel Components .......... 77
Idle Air Control Motor ...................... 78 Manifold Absolute Pressure (MAP) Sensor
Service ............................... 82
Methanol Concentration Sensor .............. 82
PCM Service ............................ 82
Service Precautions for Flexible Fuel Vehicles .... 77
Throttle Body ............................ 77
Throttle Body Removal ..................... 79
Throttle Position Sensor (TPS) ............... 78
GENERAL INFORMATION
In this model year Chrysler began producing AA-
Body vehicles designed to operate on a mixture of
gasoline and methanol. These automobiles are referred
to as Flexible Fuel vehicles. Fuel system components
designed for use in flexible fuel vehicles are referred to
as Methanol Compatible. Flexible fuel vehicles can operate on a mixture of up
to 85 percent methanol, 15 percent unleaded gasoline.
These vehicles also operate on mixtures containing a
lower percentage of methanol or just pure unleaded
gasoline.
SERVICE PRECAUTIONS FOR FLEXIBLE FUEL
VEHICLES
Methanol is more toxic than gasoline. Always release
fuel system pressure before servicing fuel system com-
ponents and wear methanol resistant gloves and eye
protection. Avoid breathing methanol vapors or ingesting
methanol. Headaches, dizziness and even unconscious-
ness could result from breathing these vapors. Serious
injury, blindness and even death could result from
ingesting methanol. Methanol vapors are extremely flammable and can
travel along the ground. Service vehicles in well ven-
tilated areas and avoid ignition sources. Never smoke
while servicing the vehicle. Do not allow methanol to contact skin. Prolonged
contact with methanol can cause dry skin or an allergic
skin reaction. Also, prolonged contact could result in
absorption through the skin.
IDENTIFYING FLEXIBLE FUEL COMPONENTS
Flexible Fuel vehicles have unique methanol compat-
ible fuel system components. Chrysler identifies methanol
compatible components that could be physically inter-
changed with gasoline only parts by coloring them green
or applying a green label or tag to them. Even though
they may appear physically identical, components
for gasoline only AA-body vehicles must not be used
on flexible fuel vehicles.
FLEXIBLE FUEL COMPONENTS
The fuel system of flexible fuel AA-body vehicles have
the following unique methanol compatible components.
² Duty cycle EVAP purge solenoid
² EVAP canister
² Fuel pump module
² Fuel level sensor
² Fuel gauge (gauge cluster).
² Fuel tank
² Fuel pressure regulator (including O-rings)
² Fuel rail
² Fuel injectors (including O-rings)
² Fuel tubes
² Fuel filter
² Fuel filler cap
² Fuel filler tube
² Methanol concentration sensor
² Pressure relief/rollover valve
² PCV Valve
² All fuel system and emission system hoses and tubes
THROTTLE BODY
WARNING: THROTTLE BODIES DESIGNED FOR
GASOLINE ONLY VEHICLES CANNOT BE USED ON
FLEXIBLE FUEL AA-BODY VEHICLES. WHEN RE-
PLACING THE THROTTLE BODY OF A FLEXIBLE
FUEL VEHICLE, ONLY USE AN ORIGINAL EQUIP-
MENT REPLACEMENT.
When servicing throttle body components, always
reassemble components with new O-rings and seals
where applicable. Never use lubricants on O-rings or
seals, damage may result. If assembly of component is
difficult, use water to aid assembly. Use care when
removing hoses to prevent damage to hose or hose
nipple.
Ä FUEL SYSTEMS 14 - 77

2.2L TURBO III MULTI-PORT FUEL INJECTIONÐON-BOARD DIAGNOSTICS INDEX
page page
60-Way PCM Wiring Connector ............. 105
Circuit Actuation Test Mode ................ 105
Diagnostic Trouble Code Description ......... 101
General Information ...................... 100
High and Low Limits ..................... 101
Ignition Timing Procedure ................. 105 Monitored Circuits
....................... 100
Non-Monitored Circuits ................... 100
State Display Test Mode .................. 104
System Tests .......................... 104
Throttle Body Minimum Air Flow Check Procedure ............................ 105
GENERAL INFORMATION
The powertrain control module (PCM) has been pro-
grammed to monitor many different circuits of the fuel
injection system. If a problem is sensed with a moni-
tored circuit often enough to indicate an actual prob-
lem, the PCM stores a fault. If the problem is repaired
or ceases to exist, the PCM cancels the Diagnostic
trouble code after 51 vehicle key on/off cycles. Certain criteria must be met for a diagnostic trouble
code to be entered into PCM memory. The criteria may
be a specific range of engine RPM, engine temperature,
and/or input voltage to the PCM. It is possible that a diagnostic trouble code for a
monitored circuit may not be entered into memory
even though a malfunction has occurred. This may
happen because one of the diagnostic trouble code
criteria for the circuit has not been met. For example,
assume that one of the diagnostic trouble code criteria
for a certain sensor circuit is that the engine must be
operating between 750 and 2000 RPM. If the sensor
output circuit shorts to ground when engine RPM is
above 2400 RPM (resulting i n a 0 volt input to the
PCM) a diagnostic trouble code will not be entered into
memory. This is because the condition does not occur
within the specified RPM range. There are several operating conditions for which the
PCM does not monitor and set diagnostic trouble codes.
Refer to Monitored Circuits and Non-Monitored Cir-
cuits in this section. Stored diagnostic trouble codes can be displayed
either by cycling the ignition key On - Off - On - Off -
On, or through use of the DRB II scan tool. The DRBII
scan tool connects to the data link connector in the
vehicle (Fig. 1).
MONITORED CIRCUITS
The powertrain control module (PCM) can detect
certain fault conditions in the fuel injection system. Open or Shorted Circuit - The PCM can determine
if the sensor output (input to PCM) is within proper
range. Also, the PCM can determine if the circuit is
open or shorted. Output Device Current Flow - The PCM senses
whether the output devices are hooked up. If there is a problem with the circuit, the PCM senses whether
the circuit is open, shorted to ground, or shorted
high. Oxygen Sensor - The PCM can determine if the
oxygen sensor is switching between rich and lean
once the system has entered closed loop. Refer to
Modes of Operation in this section for an explanation
of closed loop operation.
NON-MONITORED CIRCUITS
The PCM does not monitor the following circuits,
systems and conditions that could have malfunctions
that result in driveability problems. Diagnostic trou-
ble codes may not be displayed for these conditions.
However, problems with these systems may cause di-
agnostic trouble codes to be displayed for other sys-
tems. For example, a fuel pressure problem will not
register a fault directly, but could cause a rich or
lean condition. This could cause an oxygen sensor
fault to be stored in the PCM. Fuel Pressure - Fuel pressure is controlled by the
fuel pressure regulator. The PCM cannot detect a
clogged fuel pump inlet strainer, clogged in-line fuel
filter, or a pinched fuel supply or return line. How-
ever, these could result in a rich or lean condition
causing an oxygen sensor fault to be stored in the
PCM.
Fig. 1 Data Link Connector LocationÐAG Body
14 - 100 FUEL SYSTEMS Ä