2003 CHRYSLER CARAVAN compression ratio

ENGINE 3.3/3.8L
TABLE OF CONTENTS
page page
ENGINE 3.3/3.8L
DESCRIPTION.........................76
DIAGNOSIS AND TESTING
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - INTRODUCTION...........76
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - PERFORMANCE...........78
DIAGNOSIS AND TESTING - ENGINE
DIAGNOSIS - MECHANICAL.............80
DIAGNOSIS AND TESTING - ENGINE OIL
LEAK INSPECTION....................82
DIAGNOSIS AND TESTING - CYLINDER
COMPRESSION PRESSURE TEST........83
DIAGNOSIS AND TESTING - CYLINDER
COMBUSTION PRESSURE LEAKAGE
TEST...............................83
STANDARD PROCEDURE
STANDARD PROCEDURE - MEASURING
BEARING CLEARANCE USING
PLASTIGAGE........................84
STANDARD PROCEDURE - FORM-IN-
PLACE GASKETS AND SEALERS.........84
STANDARD PROCEDURE - ENGINE
GASKET SURFACE PREPARATION........85
STANDARD PROCEDURE - HYDROSTATIC
LOCKED ENGINE.....................85
STANDARD PROCEDURE - REPAIR OF
DAMAGED OR WORN THREADS.........86
STANDARD PROCEDURE - ENGINE CORE
AND OIL GALLERY PLUGS..............86
REMOVAL - ENGINE ASSEMBLY...........86
INSTALLATION - ENGINE ASSEMBLY........89
SPECIFICATIONS
3.3/3.8L ENGINE......................91
SPECIFICATIONS - TORQUE............95
SPECIAL TOOLS
3.3/3.8L ENGINE......................95
AIR CLEANER ELEMENT
REMOVAL.............................98
INSTALLATION.........................98
AIR CLEANER HOUSING
REMOVAL.............................99
INSTALLATION.........................99
CYLINDER HEAD
DESCRIPTION.........................99
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET............................99
REMOVAL - CYLINDER HEAD............100
CLEANING...........................100INSPECTION.........................101
INSTALLATION - CYLINDER HEAD.........101
CYLINDER HEAD COVER(S)
DESCRIPTION........................102
CYLINDER HEAD COVER - RIGHT
REMOVAL............................102
INSTALLATION........................103
CYLINDER HEAD COVER - LEFT
REMOVAL............................103
INSTALLATION........................103
INTAKE/EXHAUST VALVES & SEATS
DESCRIPTION........................104
OPERATION..........................104
STANDARD PROCEDURE - REFACING
VALVESANDVALVESEATS ............104
REMOVAL............................105
CLEANING...........................105
INSPECTION.........................105
INSTALLATION........................106
VALVE SPRINGS
DESCRIPTION........................106
OPERATION..........................106
REMOVAL
REMOVAL - CYLINDER HEAD OFF.......106
REMOVAL - CYLINDER HEAD ON........106
INSPECTION.........................108
INSTALLATION
INSTALLATION - CYLINDER HEAD OFF . . . 108
INSTALLATION - CYLINDER HEAD ON....108
ROCKER ARMS
DESCRIPTION
DESCRIPTION - ROCKER ARMS.........109
DESCRIPTION - PUSHRODS...........109
OPERATION
OPERATION - ROCKER ARMS..........109
OPERATION - PUSHRODS.............109
REMOVAL - ROCKER ARMS AND SHAFT....109
DISASSEMBLY - ROCKER ARMS AND SHAFT. . 109
ASSEMBLY - ROCKER ARMS AND SHAFT . . . 109
INSTALLATION - ROCKER ARMS AND SHAFT..110
VALVE STEM SEALS
DESCRIPTION........................111
REMOVAL............................112
INSTALLATION........................112
ENGINE BLOCK
DESCRIPTION........................112
STANDARD PROCEDURE - CYLINDER BORE
HONING............................112
CLEANING...........................112
9 - 74 ENGINE 3.3/3.8LRS
ProCarManuals.com

CONDITION POSSIBLE CAUSE CORRECTION
ENGINE LOSS OF POWER 1. Dirty or incorrectly gapped plugs. 1. Clean plugs and set gap.
2. Contamination in fuel system. 2. Clean system and replace fuel
filter.
3. Faulty fuel pump. 3. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
4. Incorrect valve timing. 4. Correct valve timing.
5. Leaking cylinder head gasket. 5. Replace cylinder head gasket.
6. Low compression. 6. Test compression of each
cylinder.
7. Burned, warped, or pitted valves. 7. Replace valves.
8. Plugged or restricted exhaust
system.8. Perform exhaust restriction test.
(Refer to 11 - EXHAUST SYSTEM -
DIAGNOSIS AND TESTING) Install
new parts, as necessary.
9. Faulty ignition coil(s). 9. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
ENGINE MISSES ON
ACCELERATION1. Dirty or incorrectly gapped spark
plugs.1. Clean spark plugs and set gap.
2. Contamination in Fuel System. 2. Clean fuel system and replace
fuel filter.
3. Burned, warped, or pitted valves. 3. Replace valves.
4. Faulty ignition coil(s). 4. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
ENGINE MISSES AT HIGH SPEED 1. Dirty or incorrect spark plug gap. 1. Clean spark plugs and set gap.
2. Faulty ignition coil(s). 2. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
3. Dirty fuel injector(s). 3. Test and replace as necessary.
(Refer to Appropriate Diagnostic
Information)
4. Contamination in fuel system. 4. Clean system and replace fuel
filter.
RSENGINE 3.3/3.8L9-79
ENGINE 3.3/3.8L (Continued)
ProCarManuals.com

(47) Connect the radiator upper hose.
(48) Connect the heater hoses. Remove pinch-off
pliers from the rear heater hoses (if equipped).
(49) Install the radiator upper support crossmem-
ber (Refer to 23 - BODY/EXTERIOR/GRILLE OPEN-
ING REINFORCEMENT - INSTALLATION).
(50) Install the wiper module (Refer to 8 - ELEC-
TRICAL/WIPERS/WASHERS/WIPER MODULE -
INSTALLATION).
(51) Connect the fuel line to fuel rail (Refer to 14 -
FUEL SYSTEM/FUEL DELIVERY/FUEL LINES -
STANDARD PROCEDURE).
(52) Install the air cleaner and hoses.
(53) Install new oil filter. Fill engine crankcase
with proper oil to correct level.
(54) Connect negative cable to battery.
(55) Fill the cooling system (Refer to 7 - COOLING
- STANDARD PROCEDURE).
(56) Start engine and run until operating temper-
ature is reached.
(57) Adjust transmission linkage, if necessary.
SPECIFICATIONS
3.3/3.8L ENGINE
DESCRIPTION SPECIFICATION
General Specification
Type 60É V-6 Engine
Number of Cylinders 6
Displacement
Ð3.3L 3.3 Liters
(201 cu. in.)
Ð3.8L 3.8 Liters
(231 cu. in.)
Bore
Ð3.3L 93.0 mm
(3.66 in.)
Ð3.8L 96.0 mm
(3.779 in.)
Stroke
Ð3.3L 81.0 mm
(3.188 in.)
Ð3.8L 87.0 mm
(3.425 in.)
Compression Ratio
Ð3.3L 9.35:1
Ð3.8L 9.6:1
DESCRIPTION SPECIFICATION
Firing Order 1-2-3-4-5-6
Cylinder Number (Front
to Rear)
ÐFront Bank 2,4,6
ÐRear Bank 1,3,5
Compression PressureÐ
Minimum689.5 kPa
(100 psi)
Max. Variation Between
Cylinders25%
Cylinder Block
Cylinder Bore Diameter
(Standard)
Ð3.3L 92.993±93.007 mm
(3.661±3.6617 in.)
Ð3.8L 95.993±96.007 mm
(3.7792±3.780 in.)
Out-of-Round (Service
Limits)0.076 mm
(0.003 in.)
Taper (Service Limits) 0.051 mm
(0.002 in.)
Lifter Bore Diameter 22.980±23.010 mm
(0.905±0.906 in.)
Deck Surface Flatness
(Max.)0.1 mm
(0.004 in.)
Pistons
Piston Diameter
Ð3.3L ÐMeasured 39.8
mm (1.567 in.) from
piston top92.968±92.998 mm
(3.660±3.661 in.)
Ð3.8L ÐMeasured 33.01
mm (1.30 in.) from piston
top95.968±95.998 mm
(3.778±3.779 in.)
Clearance in Bore @
Size Location (New)-0.005±0.039 mm
(-0.0002±0.0015 in.)
Weight
Ð3.3L 362  5 grams
(12.77  0.1764 oz.)
Ð3.8L 426  5 grams
(15.03  0.1764 oz.)
Piston Pins
Type Press Fit in Rod
(Serviced as an
Assembly)
RSENGINE 3.3/3.8L9-91
ENGINE 3.3/3.8L (Continued)
ProCarManuals.com

AIR CLEANER HOUSING
REMOVAL
(1) Disconnect the negative battery cable.
(2) Disconnect the inlet air temperature sensor
(Fig. 16).
(3) Remove the inlet hose to throttle body.
(4) Remove the bolt for air box at upper radiator
cross member.
(5) Pull air box up and off over the single locating
pin.
(6) Remove air box from vehicle
INSTALLATION
(1) Install air box into vehicle and onto the locat-
ing pin.
(2) Install bolt to hold air box to the upper radia-
tor cross member.
(3) Install the inlet hose to the throttle body.
(4) Connect the inlet air temperature sensor (Fig.
16).
(5) Connect the negative battery cable.
CYLINDER HEAD
DESCRIPTION
The aluminum cylinder heads (Fig. 17) are
designed to create high flow combustion chambers to
improve performance, while minimizing the change
to the burn rate in the chamber. The cylinder head
incorporates the combustion chamber. Two valves
per-cylinder are used with inserted valve seats and
guides. A multi-layer steel (MLS) type gasket is used
between the cylinder head and engine block.
DIAGNOSIS AND TESTINGÐCYLINDER HEAD
GASKET
A cylinder head gasket leak can be located between
adjacent cylinders or between a cylinder and the
adjacent water jacket.
Possible indications of the cylinder head gasket
leaking between adjacent cylinders are:
²Loss of engine power
²Engine misfiring
²Poor fuel economy
Possible indications of the cylinder head gasket
leaking between a cylinder and an adjacent water
jacket are:
²Engine overheating
²Loss of coolant
²Excessive steam (white smoke) emitting from
exhaust
²Coolant foaming
CYLINDER-TO-CYLINDER LEAKAGE TEST
To determine if an engine cylinder head gasket is
leaking between adjacent cylinders, follow the proce-
dures in Cylinder Compression Pressure Test (Refer
to 9 - ENGINE - DIAGNOSIS AND TESTING). An
engine cylinder head gasket leaking between adja-
cent cylinders will result in approximately a 50±70%
reduction in compression pressure.
CYLINDER-TO-WATER JACKET LEAKAGE TEST
WARNING: USE EXTREME CAUTION WHEN THE
ENGINE IS OPERATING WITH COOLANT PRES-
SURE CAP REMOVED.
VISUAL TEST METHOD
With the engine cool, remove the coolant pressure
cap. Start the engine and allow it to warm up until
thermostat opens.
If a large combustion/compression pressure leak
exists, bubbles will be visible in the coolant.
COOLING SYSTEM TESTER METHOD
WARNING: WITH COOLING SYSTEM TESTER IN
PLACE, PRESSURE WILL BUILD UP FAST. EXCES-
SIVE PRESSURE BUILT UP, BY CONTINUOUS
ENGINE OPERATION, MUST BE RELEASED TO A
SAFE PRESSURE POINT. NEVER PERMIT PRES-
SURE TO EXCEED 138 kPa (20 psi).
Install Cooling System Tester 7700 or equivalent to
pressure cap neck. Start the engine and observe the
tester's pressure gauge. If gauge pulsates with every
power stroke of a cylinder a combustion pressure
leak is evident.
Fig. 16 Inlet Air Temperature Sensor
RSENGINE 3.3/3.8L9-99
ProCarManuals.com

(6) Remove connecting rod cap. Install connecting
rod bolt protectors on connecting rod bolts (Fig. 56).
(7) Remove each piston and connecting rod assem-
bly out of the cylinder bore.
NOTE: Be careful not to nick crankshaft journals.
(8) After removal, install bearing cap on the mat-
ing rod.
INSTALLATION
(1) Before installing pistons and connecting rod
assemblies into the bore, ensure that compression
ring gaps are staggered so that neither is in line with
oil ring rail gap (Fig. 57).(2) Before installing the ring compressor, ensure
the oil ring expander ends are butted and the rail
gaps located as shown in (Fig. 57).
(3) Lubricate the piston and rings with clean
engine oil. Position a ring compressor over the piston
and rings, and tighten the compressor (Fig. 58).Be
sure position of rings does not change during
this operation.
(4) Position upper bearing onto connecting rod.
Lubricate bearing with oil.
(5) Install connecting rod bolt protectors (rubber
hose or equivalent) on the connecting rod bolts (Fig.
58).
(6) The pistons are marked with a ªFº located near
the piston pin. Install piston with this mark posi-
tioned to front of engine on both cylinder banks. The
connecting rod oil squirt hole faces the major thrust
(right) side of the engine block (Fig. 59).
(7) Rotate crankshaft until the connecting rod
journal is located in the center of the cylinder bore.
Insert connecting rod and piston into cylinder bore.
Carefully guide connecting rod over the crankshaft
journal (Fig. 58).
(8) Tap the piston down in cylinder bore, using a
hammer handle. At the same time, guide connecting
rod into position on connecting rod journal.
(9) Install lower bearing shell and connecting rod
cap (Fig. 58). Install nuts on cleaned and oiled rod
bolts and tighten to 54 N´m (40 ft. lbs.) PLUS
1¤4
turn.
(10) Repeat procedure for each piston and connect-
ing rod installation.
(11) Install the cylinder heads. (Refer to 9 -
ENGINE/CYLINDER HEAD - INSTALLATION)
(12) Install the oil pan. (Refer to 9 - ENGINE/LU-
BRICATION/OIL PAN - INSTALLATION)
(13) Fill engine crankcase with proper oil to cor-
rect level.
(14) Connect negative cable to battery.
Fig. 56 Connecting Rod Protectors
1 - COVER ROD BOLTS WITH A SUITABLE COVERING WHEN
REMOVING OR INSTALLING PISTON ASSEMBLY
Fig. 57 Piston Ring End Gap Position
1 - SIDE RAIL UPPER
2 - NO. 1 RING GAP
3 - PISTON PIN
4 - SIDE RAIL LOWER
5 - NO. 2 RING GAP AND SPACER EXPANDER GAP
9 - 118 ENGINE 3.3/3.8LRS
PISTON & CONNECTING ROD (Continued)
ProCarManuals.com

VALVE TIMING
STANDARD PROCEDURE
STANDARD PROCEDURE - VALVE TIMING
VERIFICATION
(1) Remove front cylinder head cover and all 6
spark plugs.
(2) Rotate engine until the #2 piston is at TDC of
the compression stroke.
(3) Install a degree wheel on the crankshaft pulley.
(4) With proper adaptor, install a dial indicator
into #2 spark plug hole. Using the indicator find TDC
on the compression stroke.
(5) Position the degree wheel to zero.
(6) Remove dial indicator from spark plug hole.
(7) Place a 5.08 mm (0.200 in.) spacer between the
valve stem tip of #2 intake valve and rocker arm pad.
Allow tappet to bleed down to give a solid tappet
effect.
(8) Install a dial indicator so plunger contacts the
#2 intake valve spring retainer as nearly perpendic-
ular as possible. Zero the indicator.
(9) Rotate the engine clockwise until the intake
valve has lifted .254 mm (0.010 in.).
CAUTION: Do not turn crankshaft any further clock-
wise as intake valve might bottom and result in
serious damage.
(10) Degree wheel should read 6 degrees BTDC to
6 degrees ATDC.
STANDARD PROCEDURE - MEASURING
TIMING CHAIN WEAR
NOTE: This procedure must be performed with the
timing chain cover removed (Refer to 9 - ENGINE/
VALVE TIMING/TIMING CHAIN COVER - REMOVAL).
(1) Position a scale next to timing chain so that
any movement of chain may be measured (Fig. 132).
(2) Position a torque wrench and socket on the
camshaft sprocket attaching bolt. Apply force in the
direction of crankshaft rotation to take up slack to
the following torque:
²41 N´m (30 ft. lb.) with cylinder heads installed
²20 N´m (15 ft. lb.) with cylinder heads removed
NOTE: With torque applied to the camshaft
sprocket bolt, crankshaft should not be permitted to
move. It may be necessary to block crankshaft to
prevent rotation.
(3) Holding a measuring scale along edge of chain
links (Fig. 132).(4) Apply force in the reverse direction to the fol-
lowing torque:
²41 N´m (30 ft. lb.) with cylinder heads installed
²20 N´m (15 ft. lb.) with cylinder heads removed
(5) Measure amount of sprocket/chain movement.
(6) Install a new timing chain and sprockets if
movement exceeds 3.175 mm (1/8 in.).
TIMING CHAIN COVER
REMOVAL
(1) Disconnect negative cable from battery.
(2) Drain cooling system. (Refer to 7 - COOLING -
STANDARD PROCEDURE)
(3) Raise vehicle on hoist.
(4) Drain engine oil.
(5) Remove right wheel and inner splash shield.
(6) Remove oil pan. (Refer to 9 - ENGINE/LUBRI-
CATION/OIL PAN - REMOVAL)
(7) Remove oil pick-up tube (Fig. 133).
(8) Remove accessory drive belt. (Refer to 7 -
COOLING/ACCESSORY DRIVE/DRIVE BELTS -
REMOVAL)
(9) Remove A/C compressor and set aside.
(10) Remove crankshaft vibration damper. (Refer
to 9 - ENGINE/ENGINE BLOCK/VIBRATION
DAMPER - REMOVAL)
(11) Remove radiator lower hose.
(12) Remove heater hose from timing chain cover
housing (Fig. 134) or water pump inlet tube (if
engine oil cooler equipped) (Fig. 135).
(13) Remove the right side engine mount. (Refer to
9 - ENGINE/ENGINE MOUNTING/RIGHT MOUNT
- REMOVAL)
(14) Remove idler pulley from engine bracket (Fig.
136).
(15) Remove the engine mount bracket (Fig. 136).
Fig. 132 Measuring Timing Chain Wear
1 - TORQUE WRENCH
RSENGINE 3.3/3.8L9 - 153
ProCarManuals.com

(a) Open door to mid-point of travel.
(b) Mark outline of upper roller arm on door to
assist in making adjustments.
(c) Loosen bolts attaching upper roller arm to
door (Fig. 9).
(d) Decrease the length of the upper roller arm
to increase seal compression.
(e) Increase the length of the upper roller arm to
decrease seal compression.
(f) Tighten all upper roller arm bolts.
(g) Verify door alignment, adjust as necessary.
(3) Adjust seal compression at the bottom of B-post
seal.
(a) Open door to mid-point of travel.
(b) Mark outline of lower roller arm on lower
roller arm bracket to assist in making adjustments
(Fig. 15).
(c) Loosen bolts holding lower roller arm to
lower roller arm bracket.
(d) Pivot lower roller arm toward center of vehi-
cle to decrease seal compression.
(e) Pivot lower roller arm outward to increase
seal compression.
(f) Tighten lower roller arm bolts.
(g) Verify alignment, adjust as necessary.
NOTE: Adjusting seal compression at the B-post
can affect door flushness the C-post.
STABILIZER ADJUSTMENT - UPPER/LOWER
(1) Open sliding door.
(2) Loosen the bolts holding the male stabilizers to
the sliding door enough that the stabilizers can move
with some effort.
(3) Close and then reopen sliding door.
(4) Tighten all stabilizers bolts.
STABILIZER
REMOVAL
(1) Open sliding door.
(2) Remove screws attaching stabilizer to door end
frame (Fig. 16).
(3) Remove stabilizer from vehicle.
INSTALLATION
(1) Place stabilizer in position on vehicle.
NOTE: Loose install screws first. Fit should be
snug but free to move when closing door to align to
body half stabilizer.
(2) Install screws attaching stabilizer to door end
frame.
(3) Open door and final tighten screws.
(4) Verify sliding door operation.
STABILIZER SOCKET
REMOVAL
(1) Open sliding door.
(2) Remove screws holding stabilizer socket to
B-pillar (Fig. 17).
(3) Remove stabilizer socket from vehicle.
INSTALLATION
(1) Place stabilizer socket in position on vehicle.
(2) Install screws to hold stabilizer socket to B-pil-
lar. Tighten nuts to 5 N´m (45 in. lbs.) torque.
(3) Close sliding door and verify operation.
Fig. 15 Sliding Door Lower Roller Arm
1 - POWER LOWER ROLLER ARM
2 - MANUAL LOWER ROLLER ARM
Fig. 16 SLIDING DOOR STABILIZER
1 - SLIDING DOOR
2 - STABILIZER
23 - 32 DOORS - SLIDINGRS
SLIDING DOOR (Continued)
ProCarManuals.com

period the switch ratio reaches a predetermined
value, a counter is incremented by one. The monitor
is enabled to run another test during that trip. When
the test fails 6 times, the counter increments to 3, a
malfunction is entered, and a Freeze Frame is stored,
the code is matured and the MIL is illuminated. If
the first test passes, no further testing is conducted
during that trip.
The MIL is extinguished after three consecutive
good trips. The good trip criteria for the catalyst
monitor is more stringent than the failure criteria. In
order to pass the test and increment one good trip,
the downstream sensor switch rate must be less than
45% of the upstream rate. The failure percentages
are 59% respectively.
Enabling ConditionsÐThe following conditions
must typically be met before the PCM runs the cat-
alyst monitor. Specific times for each parameter may
be different from engine to engine.
²Accumulated drive time
²Enable time
²Ambient air temperature
²Barometric pressure
²Catalyst warm-up counter
²Engine coolant temperature
²Vehicle speed
²MAP
²RPM
²Engine in closed loop
²Fuel level
Pending ConditionsÐ
²Misfire DTC
²Front Oxygen Sensor Response
²Front Oxygen Sensor Heater Monitor
²Front Oxygen Sensor Electrical
²Rear Oxygen Sensor Rationality (middle check)
²Rear Oxygen Sensor Heater Monitor
²Rear Oxygen Sensor Electrical
²Fuel System Monitor
²All TPS faults
²All MAP faults
²All ECT sensor faults
²Purge flow solenoid functionality
²Purge flow solenoid electrical
²All PCM self test faults
²All CMP and CKP sensor faults
²All injector and ignition electrical faults
²Idle Air Control (IAC) motor functionality
²Vehicle Speed Sensor
²Brake switch (auto trans only)
²Intake air temperature
ConflictÐThe catalyst monitor does not run if any
of the following are conditions are present:
²EGR Monitor in progress (if equipped)
²Fuel system rich intrusive test in progress
²EVAP Monitor in progress²Time since start is less than 60 seconds
²Low fuel level-less than 15 %
²Low ambient air temperature
²Ethanol content learn is taking place and the
ethanol used once flag is set
SuspendÐThe Task Manager does not mature a
catalyst fault if any of the following are present:
²Oxygen Sensor Monitor, Priority 1
²Oxygen Sensor Heater, Priority 1
²EGR Monitor, Priority 1 (if equipped)
²EVAP Monitor, Priority 1
²Fuel System Monitor, Priority 2
²Misfire Monitor, Priority 2
OPERATION - NON-MONITORED CIRCUITS
The PCM does not monitor all circuits, systems
and conditions that could have malfunctions causing
driveability problems. However, problems with these
systems may cause the PCM to store diagnostic trou-
ble codes for other systems or components. For exam-
ple, a fuel pressure problem will not register a fault
directly, but could cause a rich/lean condition or mis-
fire. This could cause the PCM to store an oxygen
sensor or misfire diagnostic trouble code.
The major non-monitored circuits are listed below
along with examples of failures modes that do not
directly cause the PCM to set a DTC, but for a sys-
tem that is monitored.
FUEL PRESSURE
The fuel pressure regulator controls fuel system
pressure. The PCM cannot detect a clogged fuel
pump inlet filter, clogged in-line fuel filter, 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, fuel system, or mis-
fire 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. The misfire will however,
increase the oxygen content in the exhaust, deceiving
the PCM in to thinking the fuel system is too lean.
Also see misfire detection.
CYLINDER COMPRESSION
The PCM cannot detect uneven, low, or high engine
cylinder compression. Low compression lowers O2
content in the exhaust. Leading to fuel system, oxy-
gen sensor, or misfire detection fault.
EXHAUST SYSTEM
The PCM cannot detect a plugged, restricted or
leaking exhaust system. It may set a EGR (if
equipped) or Fuel system or O2S fault.
RSEMISSIONS CONTROL25-5
EMISSIONS CONTROL (Continued)
ProCarManuals.com