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ENGINE DRIVEABILITY AND EMISSIONS
3. Connect the vacuum hoses to the EVAP canister
purge solenoid.
014RW137
4. Connect the electrical connector to the EVAP canister
purge solenoid.
014RW138
Fuel Tank Vent Valve
Removal and Installation Procedure
Refer to Fuel Pump
Linear Exhaust Gas
Recirculation (EGR) Valve
Removal Procedure
1. Disconnect the negative battery cable.2. Disconnect the electrical connector at the EGR valve.
014RW139
3. Remove the bolt and the nut from the upper intake
manifold.
014RW098
4. Remove the EGR valve from the upper intake
manifold.
5. Remove the gasket from the upper intake manifold.
Installation Procedure
1. Install the gasket on the upper intake manifold.
2. Install the EGR valve on the upper intake manifold.
3. Secure the EGR valve and the gasket with the bolt
and the nut.
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6E–329 ENGINE DRIVEABILITY AND EMISSIONS
NOTE: It is possible to install the EGR valve rotated 180
from the correct position. Make sure that the base of the
valve is placed so that it aligns with the mounting flange.
014RW098
4. Connect the electrical connector at the EGR valve.
014RW139
5. Connect the negative battery cable.
Positive Crankcase Ventilation
(PCV) Valve
Removal Procedure
1. Remove the vacuum hose at the PCV valve.
Slide the clamp back to release the hose.2. Pull the PCV valve from the rubber grommet in the
right valve cover.
014RW097
Inspection Procedure
1. Shake the valve and listen for the rattle of the needle
inside the valve.
2. If the valve does not rattle, replace the valve.
Installation Procedure
1. Push the PCV valve into the rubber grommet in the
left valve cover.
2. Install the vacuum hose on the PCV valve and secure
the vacuum hose with the clamp.
014RW097
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6E–330
ENGINE DRIVEABILITY AND EMISSIONS
Wiring and Connectors
Wiring Harness Service
The control module harness electrically connects the
control module to the various solenoids, switches and
sensors in the vehicle engine compartment and
passenger compartment.
Replace wire harnesses with the proper part number
replacement.
Because of the low amperage and voltage levels utilized
in powertrain control systems, it is essential that all wiring
in environmentally exposed areas be repaired with crimp
and seal splice sleeves.
The following wire harness repair information is intended
as a general guideline only. Refer to
Chassis Electrical f o r
all wire harness repair procedures.
Connectors and Terminals
Use care when probing a connector and when replacing
terminals. It is possible to short between opposite
terminals. Damage to components could result. Always
use jumper wires between connectors for circuit
checking. NEVER probe through Weather-Pack seals.
Use an appropriate connector test adapter kit which
contains an assortment of flexible connectors used to
probe terminals during diagnosis. Use an appropriate
fuse remover and test tool for removing a fuse and to
adapt the fuse holder to a meter for diagnosis.
Open circuits are often difficult to locate by sight because
oxidation or terminal misalignment are hidden by the
connectors. Merely wiggling a connector on a sensor, or
in the wiring harness, may temporarily correct the open
circuit. Intermittent problems may also be caused by
oxidized or loose connections.
Be certain of the type of connector/terminal before
making any connector or terminal repair. Weather-Pack
and Com-Pack III terminals look similar, but are serviced
differently.
PCM Connectors and Terminals
Removal Procedure
1. Remove the connector terminal retainer.
2. Push the wire connected to the affected terminal
through the connector face so that the terminal is
exposed.
3. Service the terminal as necessary.
Installation Procedure
1. Bend the tab on the connector to allow the terminal to
be pulled into position within the connector.
2. Pull carefully on the wire to install the connector
terminal retainer.
Wire Harness Repair: Twisted
Shielded Cable
Removal Procedure
1. Remove the outer jacket.
2. Unwrap the aluminum/mylar tape. Do not remove the
mylar.
047
3. Untwist the conductors.
4. Strip the insulation as necessary.
048
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6E–331 ENGINE DRIVEABILITY AND EMISSIONS
Installation Procedure
1. Splice the wires using splice clips and rosin core
solder.
2. Wrap each splice to insulate.
3. Wrap the splice with mylar and with the drain
(uninsulated) wire.
049
4. Tape over the whole bundle to secure.
050
Twisted Leads
Removal Procedure
1. Locate the damaged wire.
2. Remove the insulation as required.
051
Installation Procedure
1. Use splice clips and rosin core solder in order to splice
the two wires together.
052
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ENGINE DRIVEABILITY AND EMISSIONS
2. Cover the splice with tape in order to insulate it from
the other wires.
053
3. Twist the wires as they were before starting this
procedure.
054
4. Tape the wires with electrical tape. Hold in place.
055
Weather-Pack Connector
Tools Required
J 28742-A Weather-Pack II Terminal Remover
Removal Procedure
A Weather-Pack connector can be identified by a rubber
seal at the rear of the connector. This engine room
connector protects against moisture and dirt, which could
from oxidation and deposits on the terminals. This
protection is important, because of the low voltage and
the low amperage found in the electronic systems.
1. Open the secondary lock hinge on the connector.
070
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6E–333 ENGINE DRIVEABILITY AND EMISSIONS
2. Use tool J 28742-A or the equivalent to remove the
pin and the sleeve terminals. Push on J 28742-A to
release.
NOTE: Do the use an ordinary pick or the terminal may
be bent or deformed. Unlike standard blade terminals,
these terminals cannot be straightened after they have
been improperly bent.
071
3. Cut the wire immediately behind the cable seal.
072
Installation Procedure
Make certain the connectors are properly seated and all
of the sealing rings are in place when you reconnect the
leads. The secondary lock hinge provides a backup
locking feature for the connector. The secondary lock
hinge is used for added reliability. This flap should retain
the terminals even if the small terminal lock tangs are not
positioned properly.
Do not replace the Weather-Pack connections with
standard connections. Read the instructions provided
with the Weather-Pack connector and terminal packages.
1. Replace the terminal.2. Slip the new seal onto the wire.
3. Strip 5 mm (0.2”) of insulation from the wire.
4. Crimp the terminal over the wire and the seal.
073
5. Push the terminal and the connector to engage the
locking tangs.
070
6. Close the secondary locking hinge.
Com-Pack III
General Information
The Com-Pack III terminal looks similar to some
Weather-Pack terminals. This terminal is not sealed and
is used where resistance to the environment is not
required. Use the standard method when repairing a
terminal. Do not use the Weather-Pack terminal tool J
28742-A or equivalent. These will damage the terminals.
Metri-Pack
Tools Required
J 35689 Terminal Remover
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6E–334
ENGINE DRIVEABILITY AND EMISSIONS
Removal Procedure
S o m e c o n n e c t o r s u s e t e r m i n a l s c a l l e d M e t r i - P a c k S e r i e s
150. These may be used at the engine coolant
temperature (ECT) sensor.
1. Slide the seal (1) back on the wire.
2. Insert the J 35689 tool or equivalent (3) in order to
release the terminal locking tang (2).
060
3. Push the wire and the terminal out through the
connector. If you reuse the terminal, reshape the
locking tang.
Installation Procedure
Metri-Pack terminals are also referred to as “pull-to-seat”
terminals.
1. In order to install a terminal on a wire, the wire must be
inserted through the seal (2) and through the
connector (3).
2. The terminal (1) is then crimped onto the wire.
061
3. Then the terminal is pulled back into the connector to
seat it in place.
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6E–335 ENGINE DRIVEABILITY AND EMISSIONS
General Description
General Description (PCM and
Sensors)
58X Reference PCM Input
The powertrain control module (PCM) uses this signal
from the crankshaft position (CKP) sensor to calculate
engine RPM and crankshaft position at all engine speeds.
The PCM also uses the pulses on this circuit to initiate
injector pulses. If the PCM receives no pulses on this
circuit, DTC P0337 will set. The engine will not start and
run without using the 58X reference signal.
A/C Request Signal
This signal tells the PCM when the A/C mode is selected
at the A/C control head. The PCM uses this to adjust the
idle speed before turning “ON” the A/C clutch. The A/C
compressor will be inoperative if this signal is not
available to the PCM.
Refer to
A/C Clutch Circuit Diagnosis for A/C wiring
diagrams and diagnosis for the A/C electrical system.
Crankshaft Position (CKP) Sensor
The crankshaft position (CKP) sensor provides a signal
used by the powertrain control module (PCM) to calculate
the ignition sequence. The CKP sensor initiates the 58X
reference pulses which the PCM uses to calculate RPM
and crankshaft position.
Refer to
Electronic Ignition System for additional
information.
0013
Camshaft Position (CMP) Sensor and
Signal
The camshaft position (CMP) sensor sends a CMP signal
t o t h e P C M . T h e P C M u s e s t h i s s i g n a l a s a “ s y n c p u l s e ” t otrigger the injectors in the proper sequence. The PCM
uses the CMP signal to indicate the position of the #1
piston during its power stroke. This allows the PCM to
calculate true sequential fuel injection (SFI) mode of
operation. If the PCM detects an incorrect CMP signal
while the engine is running, DTC P0341 will set. If the
CMP signal is lost while the engine is running, the fuel
injection system will shift to a calculated sequential fuel
injection mode based on the last fuel injection pulse, and
the engine will continue to run. As long as the fault is
present, the engine can be restarted. It will run in the
calculated sequential mode with a 1-in-6 chance of the
injector sequence being correct.
Refer to
DTC P0341 for further information.
0014
Engine Coolant Temperature (ECT) Sensor
The engine coolant temperature (ECT) sensor is a
thermistor (a resistor which changes value based on
temperature) mounted in the engine coolant stream. Low
coolant temperature produces a high resistance of
100,000 ohms at –40
C (–40F). High temperature
causes a low resistance of 70 ohms at 130
C (266F).
The PCM supplies a 5-volt signal to the ECT sensor
through resistors in the PCM and measures the voltage.
The signal voltage will be high when the engine is cold and
low when the engine is hot. By measuring the voltage, the
PCM calculates the engine coolant temperature. Engine
coolant temperature affects most of the systems that the
PCM controls.
Tech 2 displays engine coolant temperature in degrees.
After engine start-up, the temperature should rise steadily
to about 85
C (185F). It then stabilizes when the
thermostat opens. If the engine has not been run for
several hours (overnight), the engine coolant
temperature and intake air temperature displays should
be close to each other. A hard fault in the engine coolant
sensor circuit will set DTC P0177 or DTC P0118. An
intermittent fault will set a DTC P1114 or P1115.