1996 CHRYSLER VOYAGER Service Manual

THROTTLE POSITION SENSOR (TPS)
The TPS mounts to the side of the throttle body
(Fig. 13).
The TPS connects to the throttle blade shaft. The
TPS is a variable resistor that provides the Power-
train Control Module (PCM) with an input signal
(voltage). The signal represents throttle blade posi-
tion. As the position of the throttle blade changes,
the resistance of the TPS changes.
The PCM supplies approximately 5 volts to the
TPS. The TPS output voltage (input signal to the
powertrain control module) represents throttle blade
position. The TPS output voltage to the PCM varies
from approximately 0.40 volt at minimum throttle
opening (idle) to a maximum of 3.80 volts at wide
open throttle.
Along with inputs from other sensors, the PCM
uses the TPS input to determine current engine oper-
ating conditions. The PCM also adjusts fuel injector
pulse width and ignition timing based on these
inputs.
LOCK KEY CYLINDER
The lock cylinder is inserted in the end of the
housing opposite the ignition switch. The ignition key
rotates the cylinder to 5 different detents (Fig. 14):
²Accessory
²Off (lock)
²Unlock
²On/Run
²Start
KNOCK SENSOR
The knock sensor threads into the side of the cyl-
inder block in front of the starter motor. When the
knock sensor detects a knock in one of the cylinders,
it sends an input signal to the PCM. In response, the
PCM retards ignition timing for all cylinders by a
scheduled amount.
Knock sensors contain a piezoelectric material
which constantly vibrates and sends an input voltage
(signal) to the PCM while the engine operates. As the
intensity of the crystal's vibration increase, the knock
sensor output voltage also increases.
Fig. 12 Engine Coolant Temperature SensorÐ3.3/
3.8LFig. 13 Throttle Position Sensor and Idle Air Control
Motor
Fig. 14 Ignition Lock Cylinder Detents
NSIGNITION SYSTEM 8D - 7
GENERAL INFORMATION (Continued)

NOTE: Over or under tightening effects knock sen-
sor performance, possibly causing improper spark
control.
DIAGNOSIS AND TESTING
TESTING FOR SPARK AT COILÐ2.4/3.3/3.8L
ENGINES
WARNING: THE DIRECT IGNITION SYSTEMS GEN-
ERATES APPROXIMATELY 40,000 VOLTS. PER-
SONAL INJURY COULD RESULT FROM CONTACT
WITH THIS SYSTEM.
The coil pack contains independent coils. Each coil
must be checked individually.
CAUTION: Spark plug wire damage may occur if
the spark plug is moved more than 1/4 inch away
from the engine ground.
CAUTION: Do not leave any one spark plug cable
disconnected any longer than 30 seconds or possi-
ble heat damage to catalytic converter will occur.
CAUTION: Test must be performed at idle and in
park only with the parking brake on.
Use a new spark plug and spark plug cable
for the following test.
(1) Insert a new spark plug into the new spark
plug boot. Ground the plug to the engine (Fig. 15).
Do not hold with your hand.
(2) Starting with coil insulator #1, remove it from
the DIS coil.(3) Plug the test spark plug cable onto #1 coil
tower. Make sure a good connection is made; there
should be a click sound.
(4) Crank the engine and look for spark across the
electrodes of the spark plug.
CAUTION: Always install the cable back on the coil
tower after testing to avoid damage to the coil and
catalytic converter.
(5) Repeat the above test for the remaining coils. If
there is no spark during all cylinder tests, proceed to
the Failure To Start Test.
(6) If one or more tests indicate irregular, weak, or
no spark, proceed to Check Coil Test.
TESTING FOR SPARK AT COILÐ3.0L
WARNING: APPLY PARKING BRAKE AND/OR
BLOCK THE WHEELS BEFORE PERFORMING ANY
TEST WITH THE ENGINE RUNNING.
CAUTION: Spark plug cables may be damaged if
this test is performed with more than 1/4 inch clear-
ance between the cable and engine ground.
Remove the coil secondary cable from the distribu-
tor cap. Hold the end of cable about 6 mm (1/4-inch)
away from a good engine ground using non-conduc-
tive ignition pliers (Fig. 16). Crank the engine and
inspect for spark at the coil secondary cable.
There must be a constant spark at the coil second-
ary cable. If spark is not constant or there is no
spark, proceed to the failure to start test. If the
spark is constant, continue to crank engine and,
while slowly moving coil secondary cable away from
ground, look for arcing at the coil tower. If arcing
occurs at the tower, replace the coil.
If a constant spark is present and no arcing occurs
at the coil tower, the ignition system is producing the
necessary high secondary voltage. However, make
Fig. 15 Testing For Spark
Fig. 16 Checking for Spark
8D - 8 IGNITION SYSTEMNS
GENERAL INFORMATION (Continued)

sure that the spark plugs are firing. Inspect the dis-
tributor rotor, cap, spark plug cables, and spark
plugs. If they are in proper working order, the igni-
tion system is not the reason why the engine will not
start. Inspect the fuel system and engine for proper
operation.
CHECK COIL TESTÐ2.4L
Coil one fires cylinders 1 and 4, coil two fires
cylinders 2 and 3. Each coil tower is labeled
with the number of the corresponding cylinder.
(1) Remove ignition cables and measure the resis-
tance of the cables. Resistance must be within the
range shown in the Cable Resistance Chart in Spec-
ifications. Replace any cable not within tolerance.
(2) Disconnect the electrical connector from the
coil pack.
(3) Measure the primary resistance of each coil. At
the coil, connect an ohmmeter between the B+ pin
and the pin corresponding to the cylinders in ques-
tion (Fig. 17). Resistance on the primary side of each
coil should be 0.45 - 0.65 ohm at (70É to 80É F).
Replace the coil if resistance is not within tolerance.
(4) Remove ignition cables from the secondary tow-
ers of the coil. Measure the secondary resistance of
the coil between the towers of each individual coil
(Fig. 18). Secondary resistance should be 7,000 to
15,800 ohms. Replace the coil if resistance is not
within tolerance.
CHECK COIL TESTÐ3.3/3.8L
Coil 1 fires cylinders 1 and 4, coil 2 fires cyl-
inders 2 and 5, and coil 3 fires cylinders 3 and
6. Each coil tower is labeled with the number of
the corresponding cylinder.
(1) Disconnect the electrical connector from the
coil pack (Fig. 19).
(2) Measure the primary resistance of each coil. At
the coil, connect an ohmmeter between the B+ pinand the pin corresponding to the cylinders in ques-
tion (Fig. 20). Resistance on the primary side of each
coil should be 0.45 - 0.65 ohm at 21É to 27ÉC (70É to
80ÉF). A coil that has not been allowed to cool off,
would result in inaccurate measurement results.
Replace the coil if resistance is not within tolerance.
Fig. 17 Terminal Identification
Fig. 18 Checking Ignition Coil Secondary
Resistance
Fig. 19 Ignition Coil Electrical Connector
Fig. 20 Ignition Coil Terminal Identification
NSIGNITION SYSTEM 8D - 9
DIAGNOSIS AND TESTING (Continued)

(3) Remove ignition cables from the secondary tow-
ers of the coil. Measure the secondary resistance of
the coil between the towers of each individual coil
(Fig. 21). Secondary resistance should be 7,000 to
15,800 ohms. Replace the coil if resistance is not
within tolerance.
FAILURE TO START TEST
This no-start test checks the camshaft position sen-
sor and crankshaft position sensor.
The Powertrain Control Module (PCM) supplies 8
volts to the camshaft position sensor and crankshaft
position sensor through one circuit. If the 8 volt sup-
ply circuit shorts to ground, neither sensor will pro-
duce a signal (output voltage to the PCM).
When the ignition key is turned and left in the On
position, the PCM automatically energizes the Auto
Shutdown (ASD) relay. However, the controller de-en-
ergizes the relay within one second because it has
not received a camshaft position sensor signal indi-
cating engine rotation.
During cranking, the ASD relay will not energize
until the PCM receives a camshaft position sensor
signal. Secondly, the ASD relay remains energized
only if the controller senses a crankshaft position
sensor signal immediately after detecting the cam-
shaft position sensor signal.
(1) Check battery voltage. Voltage should be
approximately 12.66 volts or higher to perform fail-
ure to start test.
(2) Disconnect the harness connector from the coil
pack.
(3) Connect a test light to the B+ (battery voltage)
terminal of the coil electrical connector and ground
as shown in (Fig. 22). The B+ wire for the DIS coil is
dark green with an orange tracer.Do not spread
the terminal with the test light probe.(4) Turn the ignition key to theON position.The
test light should flash On and then Off.Do not turn
the Key to off position, leave it in the On posi-
tion.
(a) If the test light flashes momentarily, the
PCM grounded the Auto Shutdown (ASD) relay.
Proceed to step 5.
(b) If the test light did not flash, the ASD relay
did not energize. The cause is either the relay or
one of the relay circuits. Use the DRB scan tool to
test the ASD relay and circuits. Refer to the appro-
priate Powertrain Diagnostics Procedure Manual.
Refer to the wiring diagrams section for circuit
information.
(5) Crank the engine. (If the key was placed in the
off position after step 4, place the key in the On posi-
tion before cranking. Wait for the test light to flash
once, then crank the engine.)
(6) If the test light momentarily flashes during
cranking, the PCM is not receiving a crankshaft posi-
tion sensor signal. Use the DRB scan tool to test the
crankshaft position sensor and sensor circuits. Refer
to the appropriate Powertrain Diagnostics Procedure
Manual. Refer to the wiring diagrams section for cir-
cuit information.
(7) If the test light did not flash during cranking,
unplug the crankshaft position sensor connector.
Turn the ignition key to the off position. Turn the
key to the On position, wait for the test light to
momentarily flash once, then crank the engine. If the
test light momentarily flashes, the crankshaft posi-
tion sensor is shorted and must be replaced. If the
light did not flash, the cause of the no-start is in
Fig. 21 Checking Ignition Coil Secondary
ResistanceFig. 22 Ignition Coil Engine Harness Connector
8D - 10 IGNITION SYSTEMNS
DIAGNOSIS AND TESTING (Continued)