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............................6
REMOVAL
REMOVAL - 2.4L.......................7REMOVAL - 3.3/3.8L....................7
INSTALLATION
INSTALLATION - 2.4L...................7
INSTALLATION - 3.3/3.8L.................8
KNOCK SENSOR
DESCRIPTION..........................8
OPERATION............................8
REMOVAL
REMOVAL - 2.4L.......................8
REMOVAL - 3.8L.......................8
INSTALLATION
INSTALLATION - 2.4L...................8
INSTALLATION - 3.8L...................8
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
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 SPACER
Fig. 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
(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.
INSTALLATION
INSTALLATION - 2.4L
The target magnet has locating dowels that fit into
machined locating holes in the end of the camshaft
(Fig. 7).
(1) Install target magnet in end of camshaft.
Tighten mounting screw to 3 N´m (30 in. lbs.) torque.
Over torqueing could cause cracks in magnet. If mag-
net cracks replace it.
(2) Install camshaft position sensor. Tighten sensor
mounting screws to 12.9 N´m (115 in. lbs.) torque.
(3) Carefully attach electrical connector to cam-
shaft position sensor.
(4) Connect the negative battery cable.
INSTALLATION - 3.3/3.8L
If the removed sensor is reinstalled, clean off
the old spacer on the sensor face. A NEW
SPACER must be attached to the face before
installation.Inspect O-ring for damage, replace if
necessary. If the sensor is being replaced, confirm
that the paper spacer is attached to the face and
O-ring is positioned in groove of the new sensor (Fig.
8).
(1) Apply a couple drops of clean engine oil to the
O-ring prior to installation.
(2) Install sensor in the chain case cover and
rotate into position.(3) Push sensor down until contact is made with
the camshaft gear. While holding the sensor in this
position, install and tighten the retaining bolt 14
N´m (125 in. lbs.) torque.
(4) Connect camshaft position sensor electrical
connector to harness connector.
(5) Install the air box cover and inlet hose (Fig. 5).
(6) Connect the negative battery cable.
IGNITION COIL
DESCRIPTION
The ignition coil assembly consists of 2 or 3 inde-
pendent coils molded together (Fig. 9) or (Fig. 10).
The coil assembly for the 3.3/3.8L is mounted on the
intake manifold. The coil assembly for the 2.4L is
mounted on the cylinder head cover. Spark plug
cables route to each cylinder from the coil.
OPERATION
The coil fires two spark plugs every power stroke.
One plug is the cylinder under compression, the
other cylinder fires on the exhaust stroke. The Pow-
ertrain Control Module (PCM) determines which of
the coils to charge and fire at the correct time.
The Auto Shutdown (ASD) relay provides battery
voltage to the ignition coil. The PCM provides a
ground contact (circuit) for energizing the coil. When
the PCM breaks the contact, the magnetic energy in
the coil transfers to the secondary causing the spark.
The PCM will de-energize the ASD relay if it does
not receive the crankshaft position sensor and cam-
shaft position sensor inputs. Refer to Auto Shutdown
(ASD) RelayÐPCM Output, in this section for relay
operation.
Fig. 7 Target Magnet Installation
1 - LOCATING DOWELS
2 - LOCATING HOLES (2)
Fig. 8 Camshaft Position Sensor and Spacer
1 - ELECTRICAL CONNECTOR
2 - O-RING
3 - PAPER SPACER
8I - 6 IGNITION CONTROLRS
CAMSHAFT POSITION SENSOR (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
ERRATIC POINTER
MOVEMENT.1. ERRATIC MESSAGE
FROM ANOTHER
MODULE.1.A. CHECK THE BCM USING A DRB IIITSCAN
TOOL IF OK, GO TO STEP 1.B. IF NOT OK, REFER
TO THE PROPER BODY DIAGNOSTIC
PROCEDURES MANUAL TO REPAIR THE BCM.
1.B. CHECK THE PCM USING A DRB IIITSCAN
TOOL. IF OK, GO TO STEP 1.C. IF NOT OK, REFER
TO THE PROPER POWERTRAIN DIAGNOSTIC
PROCEDURES MANUAL TO REPAIR THE PCM.
1.C. CHECK THE SPEED SIGNAL INPUT INTO THE
PCM. THE SPEED SIGNAL ORIGINATES FROM THE
TCM FOR VEHICLES WITH THE 4 SPEED
ELECTRONIC TRANSMISSIONS. CHECK
CONTINUITY FROM TCM TO PCM. IF OK, USE A
DRB IIITSCAN TOOL TO CHECK TCM. REFER TO
THE PROPER TRANSMISSION DIAGNOSTIC
PROCEDURES MANUAL TO REPAIR THE TCM. IF
NOT OK, REPAIR WIRING.
2. INTERNAL CLUSTER
FAILURE.2.A. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF THE POINTER MOVES DURING TEST BUT
STILL APPEARS ERRATIC, THEN GO TO STEP 2.B.
2.B. REPLACE CLUSTER ASSEMBLY.
RSINSTRUMENT CLUSTER8J-5
INSTRUMENT CLUSTER (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
ERRATIC POINTER
MOVEMENT.1. BAD PCI BUS
MESSAGE FROM
PCM.1. CHECK THE PCM USING A DRB IIITSCAN TOOL.
REFER TO THE PROPER POWERTRAIN DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE AND
REPAIR.
2. INTERNAL
CLUSTER FAILURE.2. PERFORM CLUSTER SELF-DIAGNOSTIC TEST AND
CHECK FOR FAULT CODES.
²IF THE POINTER MOVES DURING TEST BUT STILL
APPEARS ERRATIC, REPLACE CLUSTER ASSEMBLY.
TACHOMETER
INACCURATE.TACHOMETER OUT
OF CALIBRATION.PERFORM CLUSTER SELF-DIAGNOSTIC TEST.
²IF TACHOMETER IS ACCURATE TO THE CALIBRATION
POINTS, LOOK FOR ANOTHER POSSIBLE CAUSE OF
INACCURACY.
²IF TACHOMETER IS NOT ACCURATE TO THE
CALIBRATION POINTS, REPLACE CLUSTER ASSEMBLY.
FUEL GAUGE DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO POINTER
MOVEMENT.1. INTERNAL CLUSTER
FAILURE.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST.
²IF FUEL GAUGE POINTER MOVES TO
CALIBRATION POINTS, LOOK FOR ANOTHER
POSSIBLE CAUSE OF FAILURE.
²IF THE POINTER DOESN'T MOVE DURING TEST,
VERIFY POWER AND GROUND ARE BEING
PROVIDED TO THE CLUSTER. IF YES, REPLACE
CLUSTER ASSEMBLY. IF NO, DETERMINE CAUSE
OF NO POWER OR GROUND.
2. NO PCI FUEL
MESSAGE OR EMPTY
PCI BUS MESSAGE
FROM BODY CONTROL
MODULE.2.A. CHECK THE BCM USING A DRB IIITSCAN
TOOL. IF OK, GO TO STEP 2.B. IF NOT OK, REFER
TO THE PROPER BODY DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE
AND REPAIR.
2.B. REFER TO THE FUEL SECTION OF THE
SERVICE MANUAL FOR THE FUEL LEVEL SENDING
UNIT TEST PROCEDURE. TEST UNIT AND REPAIR
AS INSTRUCTED.
RSINSTRUMENT CLUSTER8J-7
INSTRUMENT CLUSTER (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
ERRATIC POINTER
MOVEMENT.1. BAD PCI FUEL
MESSAGE FROM THE
BODY CONTROLLER.1. USE A DRB IIITSCAN TOOL TO CHECK THE BCM.
IF OK, GO TO STEP 2. IF NOT OK, REFER TO THE
PROPER BODY DIAGNOSTIC PROCEDURES
MANUAL TO PROPERLY DIAGNOSE AND REPAIR.
2. REFER TO THE FUEL SECTION OF THE SERVICE
MANUAL FOR THE FUEL LEVEL SENDING UNIT
TEST PROCEDURE. TEST UNIT. IF OK, LOOK FOR
ANOTHER POSSIBLE CAUSE FOR FUEL GAUGE
FAILURE. IF NOT OK, REPAIR SENDING UNIT.
2. INTERNAL CLUSTER
FAILURE.2. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF THE POINTER MOVES DURING TEST BUT
STILL APPEARS ERRATIC, REPLACE CLUSTER
ASSEMBLY.
FUEL GAUGE
INACCURATE.1. FUEL GAUGE OUT OF
CALIBRATION.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST. IF
POINTER IS ACCURATE TO THE CALIBRATION
POINTS LOOK FOR ANOTHER POSSIBLE CAUSE
OF FAILURE. IF POINTER IS INACCURATE TO THE
CALIBRATION POINTS, REPLACE CLUSTER
ASSEMBLY.
2. FUEL LEVEL
SENDING UNIT IS OUT
OF CALIBRATION.2. REFER TO THE FUEL SECTION OF THE SERVICE
MANUAL FOR TESTING AND REPAIR PROCEDURE.
TEMPERATURE GAUGE DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO POINTER
MOVEMENT.1. INTERNAL CLUSTER
FAILURE.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK.
²IF TEMPERATURE GAUGE POINTER MOVES TO
CALIBRATION POINTS, LOOK FOR ANOTHER
POSSIBLE CAUSE OF FAILURE.
²IF THE POINTER DOESN'T MOVE DURING TEST,
VERIFY POWER AND GROUND ARE BEING
PROVIDED TO THE CLUSTER. IF YES, REPLACE
CLUSTER. IF NO, DETERMINE CAUSE OF NO
POWER OR NO GROUND.
2. NO PCI
TEMPERATURE
MESSAGE OR COLD PCI
BUS MESSAGE FROM
THE POWERTRAIN
CONTROL MODULE.2.A. CHECK PCM FAULT CODES USING A DRB IIIT
SCAN TOOL. IF THERE ARE NO FAULTS, GO TO
STEP 2.B. IF THERE ARE FAULTS, REFER TO THE
PROPER POWERTRAIN DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE
AND REPAIR.
2.B. REFER TO FUEL, COOLANT TEMPERATURE
SENSOR, DIAGNOSIS AND TESTING. REPAIR
SENSOR AS NEEDED.
8J - 8 INSTRUMENT CLUSTERRS
INSTRUMENT CLUSTER (Continued)
CONDITION POSSIBLE CAUSES CORRECTION
ERRATIC POINTER
MOVEMENT.1. BAD PCI BUS
MESSAGE FROM THE
POWERTRAIN CONTROL
MODULE.1.A. CHECK PCM FAULT CODES USING A DRB IIIT
SCAN TOOL. IF THERE ARE NO FAULTS, GO TO
STEP 1.B. IF THERE ARE FAULTS, REFER TO THE
PROPER POWERTRAIN DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE
AND REPAIR.
1.B. REFER TO FUEL, COOLANT TEMPERATURE
SENSOR, DIAGNOSIS AND TESTING. REPAIR
SENSOR AS NEEDED.
2. INTERNAL CLUSTER
FAILURE.2. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF THE POINTER MOVES DURING TEST BUT
STILL APPEARS ERRATIC, REPLACE CLUSTER
ASSEMBLY.
TEMPERATURE GAUGE
INACCURATE.1. TEMPERATURE
GAUGE OUT OF
CALIBRATION.1. PERFORM CLUSTER SELF-DIAGNOSTIC TEST.
²IF POINTER IS ACCURATE TO THE CALIBRATION
POINTS LOOK FOR ANOTHER POSSIBLE CAUSE
OF FAILURE.
²IF POINTER IS INACCURATE TO THE
CALIBRATION POINTS, REPLACE CLUSTER
ASSEMBLY.
2. COOLANT SENSOR
OUT OF CALIBRATION.2. REFER TO FUEL, COOLANT TEMPERATURE
SENSOR FOR TEST AND REPAIR PROCEDURE.
ODOMETER DIAGNOSIS
CONDITION POSSIBLE CAUSES CORRECTION
NO DISPLAY. 1. NO PCI BUS
ODOMETER MESSAGE
FROM BCM.1. USE A DRB IIITSCAN TOOL TO CHECK THE BCM.
REFER TO THE PROPER BODY DIAGNOSTIC
PROCEDURES MANUAL TO PROPERLY DIAGNOSE
AND REPAIR.
2. INTERNAL CLUSTER
FAILURE.2. PERFORM CLUSTER SELF-DIAGNOSTIC TEST
AND CHECK FOR FAULT CODES.
²IF ODOMETER PASSES THE SEGMENT CHECK,
LOOK FOR ANOTHER POSSIBLE CAUSE OF
FAILURE. IF IT FAILS VERIFY POWER AND
GROUND ARE BEING PROVIDED TO THE
CLUSTER. IF YES, REPLACE CLUSTER. IF NO,
DETERMINE CAUSE OF NO POWER OR GROUND.
RSINSTRUMENT CLUSTER8J-9
INSTRUMENT CLUSTER (Continued)
LAMPS/LIGHTING - EXTERIOR
DESCRIPTION
LAMP SYSTEMS
Lighting circuits are protected by fuses. Lighting
circuits require an overload protected power and high
side drivers source, ON/OFF device, lamps and body
grounds to operate properly. Plastic lamps require a
wire in the harness to supply body ground to the
lamp socket. Replace sockets and bulbs that are cor-
roded.
Some of the interior and exterior lighting functions
are governed by the Body Control Module (BCM).
The headlamp, dome, and the door ajar switches pro-
vide signals to the BCM. The BCM in turn sends a
Programmable Communication Interface (PCI) bus
message to the Front Control Module (FCM) to
enable the necessary drivers to set the required illu-
mination configuration.
Wire connectors can make intermittent contact or
become corroded. Before coupling wire connectors,
inspect the terminals inside the connector. Male ter-
minals should not be bent or disengaged from the
insulator. Female terminals should not be sprung
open or disengaged from the insulator. Bent and
sprung terminals can be repaired using needle nose
pliers and pick tool. Corroded terminals appear
chalky or green. Corroded terminals should be
replaced to avoid recurrence of the problem symp-
toms.
Begin electrical system failure diagnosis by testing
related fuses in the fuse block and intelligent power
module. Verify that bulbs are in good condition and
test continuity of the circuit ground. Refer to the
appropriate wiring information.
AUTOMATIC HEADLAMP SYSTEM
The Automatic Headlamp system turns the instru-
mentation and exterior illumination lamps ON when
the ambient light levels are Night and the engine
RPM is 450 or above, and OFF when light levels are
Day.
DAYTIME RUNNING LAMPS
Operating the high-beam headlamps at reduced
power provides daytime running lamps, which are
required on all new Canadian vehicles. Daytime run-
ning lamps are functional when 450 rpm's are
reached.
HEADLAMPS ON WITH WINDSHIELD WIPERS
For vehicles equipped with the Automatic Head-
lamp System, the instrumentation and exterior illu-
mination lamps will be turned ON when the
headlamp switch is in the AUTO position, RPM >450 and the windshield wipers have been in the
intermittent, low or high mode of operation for more
than ten seconds. When the windshield wipers are
turned OFF the Body Control Module will determine
if the instrumentation and exterior illumination
lamps should remain ON base upon the current
ambient light level.
HEADLAMP SYSTEM
The configuration of the headlamp system of head-
lamps, park lamps and fog lamps is determined by
the BCM. The BCM determines the lighting configu-
ration as a result of the inputs from the ignition
switch, headlamp switch and multi-function switch. A
PCI bus is transmitted from the BCM to the FCM to
enable the necessary drivers to set the illumination
configuration. Four wires are connected between the
headlamp switch and the BCM. The first wire con-
tains information regarding the position of the head-
lamp switch (Off, Automatic Headlamps, Automatic
Headlamp switch fog, Park with Fog, Head, or Head
with Fog Lamps). The second wire contains informa-
tion regarding the position of the dimmer switch
(Dome Lamp, Daytime Brightness, Dimming Level or
Off). The third wire is a dedicated signal return
(ground) wire. The fourth wire provides power to the
front fog lamp indicator.
HEADLAMP TIME DELAY SYSTEM
The headlamp time delay system is controlled by
the Body Control Module (BCM) via a PCI bus mes-
sage transmitted by the BCM to the FCM to turn off
the headlamps.
OPERATION
AUTOMATIC HEADLAMP SYSTEM
Automatic headlamps are controlled by the Body
Control Module (BCM). With the headlamp switch in
the AUTO position, the BCM will control the head-
lamp, parking, side marker, tail and instrumentation
lamps based on ambient light levels. Ambient light
levels are monitored by the BCM using the Day/
Night signal and Electrochromatic Mirror (ECM)
present from the Compass Mini Trip (CMTC) located
on the front windshield in front of the rear view mir-
ror ECM. Ambient light readings are averaged to
limit cycling the lamps ON and OFF when passing
through areas with varying light levels. The auto-
matic headlamps will only function when the engine
is running with RPM > 450. When the headlamp
switch is in the AUTO position (Automatic mode), the
Headlamp Time Delay system will function when the
ignition switch is placed in any position other than
run/start.
8L - 2 LAMPS/LIGHTING - EXTERIORRS