Page 513 of 2585

(4) Install horn relay into Integrated Power Mod-
ule (IPM).
(a) If horn does not sound, replace airbag trim
cover.
(b) If horn sounds, repair grounded X3 circuit
from IPM to clockspring in the steering column.
HORNS WILL NOT SOUND
Check horn fuse#8intheIPM. If fuse is blown,
check for a shorted switch in the airbag module. and
refer to FUSE BLOWN section. If fuse is OK, refer to
FUSE OK section.
FUSE BLOWN
(1) Verify condition of battery terminals and volt-
age, (Refer to 8 - ELECTRICAL/BATTERY SYSTEM
- DIAGNOSIS AND TESTING). If battery connec-
tions and battery charge is OK proceed to Step 2.
(2) Using a voltmeter, test for battery voltage at
both sides of horn fuse 7. If voltage is OK, on both
sides of fuse, proceed to Fuse OK. If voltage is OK,
on one side of fuse, the fuse is blown, proceed to Step
3.
(3) Using a suitable ammeter in place of the fuse,
test amperage draw of the horn circuit. If amperage
draw is greater than 20 amps without the horn
switch depressed, a grounded circuit exists between
the fuse and the horn relay. Proceed to Step 4. If
amperage draw is greater than 20 amps with the
horn switch depressed, a grounded circuit exists
between the horn relay and the horn. Proceed to step
Step 5.
(4) Remove the horn relay from the IPM. If the
amperage draw drops to 0 amps, the horn switch or
circuit is shorted. If the amperage draw does not
drop to 0 amps, repair short at the IPM.
(5) Disengage a wire connector from one of the
horns. If amperage drops and the connected horn
sounds, replace the faulty horn. If amperage does not
drop with both horns disconnected and the horn
switch depressed, proceed to Step 6.
(6) Using a continuity tester, with the horns dis-
connected test continuity of the X2 cavity of the horn
relay to ground. If continuity is detected, the circuit
is grounded between the Junction Block and the
horns. Locate and repair pinched harness.
FUSE OK
(1) Remove the horn relay from the intelligent
power module.
(2) Using a continuity tester, Depress horn switch
and test continuity from the X3 cavity of the horn
relay to ground.
(a) If continuity is detected, proceed to Step 3.
(b) If NO continuity, proceed to Step 4.(3) Using a suitable jumper wire, jump across the
fuse F62 cavity and the X2 cavity of the horn relay in
the Junction Block.
(a) If the horn sounds, replace the horn relay.
(b) If the horn does not sound, proceed to Step 4.
(4) Remove airbag trim cover from steering wheel.
Refer to ELECTRICAL, RESTRAINTS.
(5) Test continuity across horn switch connectors
with horn switch depressed.
(a) If continuity is detected, repair open circuit
between the relay and the horn switch.
(b) If NO continuity, replace airbag trim cover.
(6) Install horn relay into intelligent power mod-
ule.
(7) Disengage wire connectors from horns.
(8) Using a voltmeter, with the horn switch
depressed test voltage across horn connector termi-
nals of the wire harness (Fig. 1).
(a) If voltage is detected, replace horns.
(b) If NO voltage, proceed to step Step 9.
(9) With the horn switch depressed, test for volt-
age between the X2 circuit and ground.
(a) If voltage OK, repair system ground at right
cowl area.
(b) If NO voltage, repair open X2 circuit between
the relay and the horns.
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Hoist and support the front of the vehicle on
safety stands.
(3) From behind the front fascia and forward of
the left front wheel, disconnect the wire connectors
from horn.
(4) Remove the mounting bracket attaching nut
from the bottom of radiator closure panel. Do not
remove the horn from mounting bracket.
(5) Separate the horn(s) from vehicle.
Fig. 1 Horn Connector
8H - 4 HORNRS
HORN (Continued)
Page 514 of 2585
INSTALLATION
(1) Install the horns to the vehicle.
(2) Install the mounting bracket fastener.
(3) Reconnect the wire connectors to the horns.
(4) Lower the vehicle.
(5) Reconnect the battery negative cable.
HORN SWITCH
DESCRIPTION
The horn switch is molded into the airbag trim
cover. The horn switch can not be serviced separately.
For service procedures (Refer to 8 - ELECTRICAL/
RESTRAINTS/AIRBAG COVER - REMOVAL).
RSHORN8H-5
HORN (Continued)
Page 515 of 2585
Page 516 of 2585

IGNITION CONTROL
TABLE OF CONTENTS
page page
IGNITION CONTROL
DESCRIPTION - IGNITION SYSTEM..........1
OPERATION - IGNITION SYSTEM...........1
SPECIFICATIONS
TORQUE.............................2
SPARK PLUG CABLE RESISTANCE........2
SPARK PLUG.........................2
FIRING ORDER........................3
AUTO SHUT DOWN RELAY
DESCRIPTION..........................3
OPERATION............................3
CAMSHAFT POSITION SENSOR
DESCRIPTION..........................4
OPERATION............................4
REMOVAL
REMOVAL - 2.4L.......................5
REMOVAL - 3.3/3.8L....................5
INSTALLATION
INSTALLATION - 2.4L...................6
INSTALLATION - 3.3/3.8L.................6
IGNITION COIL
DESCRIPTION..........................6
OPERATION............................7
REMOVAL
REMOVAL - 2.4L.......................7REMOVAL - 3.3/3.8L....................7
INSTALLATION
INSTALLATION - 2.4L...................7
INSTALLATION - 3.3/3.8L.................7
KNOCK SENSOR
DESCRIPTION..........................8
OPERATION............................8
REMOVAL
REMOVAL - 2.4L.......................8
REMOVAL - 3.8L.......................8
INSTALLATION
INSTALLATION - 2.4L...................9
INSTALLATION - 3.8L...................9
SPARK PLUG
DESCRIPTION
DESCRIPTION - STANDARD 4 CYLINDER . . . 9
DESCRIPTION - PLATINUM PLUGS........9
REMOVAL.............................10
INSTALLATION.........................10
SPARK PLUG CABLE
DESCRIPTION.........................10
REMOVAL - 2.0/2.4L.....................10
INSTALLATION - 2.0/2.4L.................10
IGNITION CONTROL
DESCRIPTION - IGNITION SYSTEM
NOTE: All engines use a fixed ignition timing sys-
tem. Basic ignition timing is not adjustable. All
spark advance is determined by the Powertrain
Control Module (PCM).
The ignition system used on these engines is
referred to as the Direct Ignition System (DIS). The
system's three main components are the coils, crank-
shaft position sensor, and camshaft position sensor. If
equipped with the coil on plug ignition system it uti-
lizes an ignition coil for every cylinder, it is mounted
directly over the each spark plug.
OPERATION - IGNITION SYSTEM
The crankshaft position sensor and camshaft posi-
tion sensor are hall effect devices. The camshaft posi-
tion sensor and crankshaft position sensor generate
pulses that are inputs to the PCM. The PCM deter-
mines engine position from these sensors. The PCM
calculates injector sequence and ignition timing from
crankshaft & camshaft position. For a description of
both sensors, refer to Camshaft Position Sensor and
Crankshaft Position Sensor.
RSIGNITION CONTROL8I-1
Page 517 of 2585
SPECIFICATIONS
TORQUE
DESCRIPTION N´m Ft. Lbs. In. Lbs.
2.4L Target Magnet Screw 3 30
2.4L Camshaft Sensor
Screw12.9 115
3.3/3.8L Camshaft Sensor
Screw14.1 125
2.4L Ignition coil bolts 11.8 105
3.3/3.8LIgnition coil bolts 11.8 105
Spark Plugs 17.5 13
Knock Sensor 10 7
SPARK PLUG CABLE RESISTANCE
2.4L
CABLE Maximum Resistance
1, 2, 3, & 4 10.8K ohms
3.3/3.8L
CABLE Maximum Resistance
#1 22.5K ohms
#2 22.8K ohms
#3 19.3K ohms
#4 19.3K ohms
#5 13.6K ohms
#6 16.4K ohms
SPARK PLUG
Engine Spark Plug Gap Thread Size
2.4L RE14MCC5 0.048 TO 0.053 14mm (1 in.) reach
Engine Spark Plug Gap Thread Size
3.3L RE14PLP5 0.048 TO 0.053 14mm (1 in.) reach
3.8L RE14PLP5 0.048 TO 0.053 14mm (1 in. ) reach
8I - 2 IGNITION CONTROLRS
IGNITION CONTROL (Continued)
Page 518 of 2585

FIRING ORDERAUTO SHUT DOWN RELAY
DESCRIPTION
The relay is located in the Power Distribution Cen-
ter (PDC). For the location of the relay within the
PDC, refer to the PDC cover for location. Check elec-
trical terminals for corrosion and repair as necessary
OPERATION
The engine switched battery (NGC vehicles)
informs the PCM when the ASD relay energizes. A 12
volt signal at this input indicates to the PCM that
the ASD has been activated. This input is also used
to power certain drivers on NGC vehicles.
When energized, the ASD relay on NGC vehicles
provides power to operate the injectors, ignition coil,
generator field, O2 sensor heaters (both upstream
and downstream), evaporative purge solenoid, EGR
solenoid (if equipped) wastegate solenoid (if
equipped), and NVLD solenoid (if equipped).
The ASD relay also provides a sense circuit to the
PCM for diagnostic purposes. If the PCM does not
receive 12 volts from this input after grounding the
control side of the ASD relay, it sets a Diagnostic
Trouble Code (DTC). The PCM energizes the ASD
any time there is an engine speed that exceeds a pre-
determined value (typically about 50 rpm). The ASD
relay can also be energized after the engine has been
turned off to perform an O2 sensor heater test, if
vehicle is equipped with OBD II diagnostics.
As mentioned earlier, the PCM energizes the ASD
relay during an O2 sensor heater test. On NGC vehi-
cles it checks the O2 heater upon vehicle start. The
PCM still operates internally to perform several
checks, including monitoring the O2 sensor heaters.
FIRING ORDER 2.4L
Firing Order 1-2-3-4-5-6 3.3/3.8L
1 - Electrical Connector
RSIGNITION CONTROL8I-3
IGNITION CONTROL (Continued)
Page 519 of 2585

CAMSHAFT POSITION
SENSOR
DESCRIPTION
The camshaft position sensor for the 3.3/3.8L is
mounted in the front of the timing case cover (Fig. 6)
and the camshaft position sensor for the 2.4L is
mounted on the end of the cylinder head (Fig. 3).
OPERATION
The camshaft position sensor provides cylinder
identification to the Powertrain Control Module
(PCM) (Fig. 1). The sensor generates pulses as
groups of notches on the camshaft sprocket pass
underneath it (Fig. 2). The PCM keeps track of
crankshaft rotation and identifies each cylinder by
the pulses generated by the notches on the camshaft
sprocket. Four crankshaft pulses follow each group of
camshaft pulses.
When the PCM receives 2 cam pulses followed by
the long flat spot on the camshaft sprocket, it knows
that the crankshaft timing marks for cylinder 1 are
next (on driveplate). When the PCM receives one
camshaft pulse after the long flat spot on the
sprocket, cylinder number 2 crankshaft timing marks
are next. After 3 camshaft pulses, the PCM knows
cylinder 4 crankshaft timing marks follow. One cam-
shaft pulse after the 3 pulses indicates cylinder 5.
The 2 camshaft pulses after cylinder 5 signals cylin-
der 6 (Fig. 2). The PCM can synchronize on cylinders
1or4.When metal aligns with the sensor, voltage goes
low (less than 0.3 volts). When a notch aligns with
the sensor, voltage switches high (5.0 volts). As a
group of notches pass under the sensor, the voltage
switches from low (metal) to high (notch) then back
to low. The number of notches determine the amount
of pulses. If available, an oscilloscope can display the
square wave patterns of each timing event.
Top Dead Center (TDC) does not occur when
notches on the camshaft sprocket pass below the sen-
sor. TDC occurs after the camshaft pulse (or pulses)
and after the 4 crankshaft pulses associated with the
particular cylinder. The arrows and cylinder call outs
on (Fig. 2) represent which cylinder the flat spot and
notches identify, they do not indicate TDC position.
Fig. 1 Camshaft Position Sensor
1 - ELECTRICAL CONNECTOR
2 - O-RING
3 - PAPER SPACERFig. 2 Camshaft Sprocket
1 - CAMSHAFT SPROCKET
2 - CYL #6
3 - CYL #5
4 - CYL #4
5 - CYL #3
6 - CYL #2
7 - CYL #1
8I - 4 IGNITION CONTROLRS
Page 520 of 2585

REMOVAL
REMOVAL - 2.4L
The camshaft position sensor is mounted to the
rear of the cylinder head.
(1) Remove the negative battery cable.
(2) Disconnect electrical connectors from the cam-
shaft position sensor (Fig. 3).
(3) Remove camshaft position sensor mounting
screws. Remove sensor.
(4) Loosen screw attaching target magnet to rear
of camshaft and remove magnet (Fig. 4).
REMOVAL - 3.3/3.8L
(1) Disconnect the negative battery cable.
(2)
Remove the air box cover and inlet tube (Fig. 5).
(3) Disconnect camshaft position sensor electrical
connector from the wiring harness connector (Fig. 6).
(4) Remove bolt holding sensor.
(5) Rotate sensor away from block.
(6) Pull sensor up out of the chain case cover.Do
not pull on the sensor wiring.There is an O-ring
on the body of the sensor. The O-ring may make
removal difficult. A light tap to top of sensor prior to
removal may reduce force needed for removal.
Fig. 3 EGR/CAM SENSOR 2.4L
Fig. 4 Target Magnet Removal/Installation
1 - TARGET MAGNET
2 - MOUNTING BOLT
3 - REAR OF CYLINDER HEAD
Fig. 5 AIR BOX COVER
Fig. 6 CAMSHAFT POSITION SENSOR
RSIGNITION CONTROL8I-5
CAMSHAFT POSITION SENSOR (Continued)