Content .. 978 979 980 981 ..

Chrysler RG Voyager. Manual - part 980

present (caused by a lean air/fuel mixture, can be
caused by misfire and exhaust leaks), the sensors
produces a low voltage. When there is a lesser
amount of oxygen present (caused by a rich air/fuel
mixture, can be caused by internal engine problems)
it produces a higher voltage. By monitoring the oxy-
gen content and converting it to electrical voltage,
the sensors act as a rich-lean switch.

The oxygen sensors are equipped with a heating

element that keeps the sensors at proper operating
temperature during all operating modes. Maintaining
correct sensor temperature at all times allows the
system to enter into closed loop operation sooner.
Also, it allows the system to remain in closed loop
operation during periods of extended idle.

In Closed Loop operation the PCM monitors the O2

sensors input (along with other inputs) and adjusts
the injector pulse width accordingly. During Open
Loop operation the PCM ignores the O2 sensor input.
The PCM adjusts injector pulse width based on pre-
programmed (fixed) values and inputs from other
sensors.

NGC Controller - Has a common ground for the

heater in the O2S. 12 volts is supplied to the heater
in the O2S by the NGC controller. Both the upstream
and downstream O2 sensors for NGC are pulse width
modulation (PWM). NOTE: When replacing an O2
Sensor, the PCM RAM memory must be cleared,
either by disconnecting the PCM C-1 connector or
momentarily disconnecting the Battery negative ter-
minal. The NGC learns the characteristics of each O2
heater element and these old values should be
cleared when installing a new O2 sensor. The cus-
tomer may experience driveability issues if this is not
performed.

UPSTREAM OXYGEN SENSOR

The input from the upstream heated oxygen sensor

tells the PCM the oxygen content of the exhaust gas.
Based on this input, the PCM fine tunes the air-fuel
ratio by adjusting injector pulse width.

The sensor input switches from 2.5 to 3.5 volt,

depending upon the oxygen content of the exhaust
gas in the exhaust manifold. When a large amount of

oxygen is present (caused by a lean air-fuel mixture),
the sensor produces voltage as low as 2.5 volt. When
there is a lesser amount of oxygen present (rich air-
fuel mixture) the sensor produces a voltage as high
as 3.5 volt. By monitoring the oxygen content and
converting it to electrical voltage, the sensor acts as
a rich-lean switch.

The heating element in the sensor provides heat to

the sensor ceramic element. Heating the sensor
allows the system to enter into closed loop operation
sooner. Also, it allows the system to remain in closed
loop operation during periods of extended idle.

In Closed Loop, the PCM adjusts injector pulse

width based on the upstream heated oxygen sensor
input along with other inputs. In Open Loop, the
PCM adjusts injector pulse width based on prepro-
grammed (fixed) values and inputs from other sen-
sors.

DOWNSTREAM OXYGEN SENSOR

The downstream heated oxygen sensor input is

used to detect catalytic convertor deterioration. As
the convertor deteriorates, the input from the down-
stream sensor begins to match the upstream sensor
input except for a slight time delay. By comparing
the downstream heated oxygen sensor input to the
input from the upstream sensor, the PCM calculates
catalytic convertor efficiency. Also used to establish
the upstream O2 goal voltage (switching point).

REMOVAL

REMOVAL - UPSTREAM 1/1 - 2.4L

(1) Disconnect the negative battery cable.
(2) Raise and support the vehicle.
(3) Disconnect the electrical connector (Fig. 23).
(4) Use a socket such as the Snap-On

t YA8875 or

equivalent to remove the sensor

(5) When the sensor is removed, the threads must

be cleaned with an 18 mm X 1.5 + 6E tap. If using
the original sensor, coat the threads with Loctite
771–64 anti-seize compound or equivalent.

FUEL INJECTION

14 - 37

O2 SENSOR (Continued)

REMOVAL - UPSTREAM 1/1 - 3.3/3.8L

(1) Remove battery, refer to the Battery section for

more information.

(2) Remove the battery tray, refer to the Battery

section for more information.

(3) Disconnect the speed control vacuum harness

from servo.

(4) Disconnect the electrical connector from servo.

(5) Remove the speed control servo and bracket

and reposition.

(6) Use a socket such as the Snap-On

t YA8875 or

equivalent to remove the sensor (Fig. 25).

(7) When the sensor is removed, the threads must

be cleaned with an 18 mm X 1.5 + 6E tap. If using
the original sensor, coat the threads with Loctite
771–64 anti-seize compound or equivalent.

REMOVAL - DOWNSTREAM 1/2 - 2.4/3.3/3.8L

(1) Disconnect the negative battery cable.
(2) Raise and support the vehicle.
(3) Disconnect the electrical connector (Fig. 26).
(4) Use a socket such as the Snap-On

t YA8875 or

equivalent to remove the sensor (Fig. 27).

(5) When the sensor is removed, the threads must

be cleaned with an 18 mm X 1.5 + 6E tap. If using
the original sensor, coat the threads with Loctite
771–64 anti-seize compound or equivalent.

INSTALLATION

INSTALLATION - UPSTREAM 1/1 - 2.4L

The engines uses two heated oxygen sensors.
(1) After removing the sensor, the exhaust mani-

fold threads must be cleaned with an 18 mm X 1.5 +
6E tap. If reusing the original sensor, coat the sensor
threads with an anti-seize compound such as Loctite
771- 64 or equivalent. New sensors have compound
on the threads and do not require an additional coat-
ing.

Fig. 25 O2 SENSOR 1/1

Fig. 26 Downstream Oxygen Sensor (1/2)

1 - OXYGEN SENSOR CONNECTOR
2 - CATALYTIC CONVERTER
3 - DOWNSTREAM OXYGEN SENSOR
4 - ENGINE HARNESS CONNECTOR

Fig. 27 DOWNSTREAM 2/1 O2 SENSOR

14 - 38

FUEL INJECTION

O2 SENSOR (Continued)

(2) Install sensor and tighten to 27 N·m (20 ft.

lbs.) (Fig. 23).

(3) Connect the electrical connector for the O2 sen-

sor and install onto bracket.

(4) Lower vehicle.
(5) Connect the negative battery cable.

INSTALLATION - UPSTREAM 1/1 - 3.3/3.8L

The engines uses two heated oxygen sensors.
(1) After removing the sensor, the exhaust mani-

(2) Install sensor and tighten to 27 N·m (20 ft.

lbs.).

(3) Connect the electrical connector for the O2 sen-

sor and install onto bracket.

(4) Connect the electrical connector for the speed

control servo.

(5) Install the speed control servo and bracket

refer to the Speed Control Servo for more informa-
tion.

(6) Connect the speed control vacuum harness to

servo.

(7) Install the battery tray, refer to the Battery

section for more information.

(8) Install battery, refer to the Battery section for

more information.

INSTALLATION DOWNSTREAM 2/1 -
2.4/3.3/3.8L

The O2S is located on the side of the catalytic con-

verter.

Threads of new oxygen sensors are factory coated

with anti-seize compound to aid in removal. DO
NOT add any additional anti-seize compound to
the threads of a new oxygen sensor.

(1) Install sensor and tighten to 27 N·m (20 ft.

lbs.).

(2) Connect the electrical connector.
(3) Lower vehicle.
(4) Install the negative battery cable.

THROTTLE BODY

DESCRIPTION

The throttle body is located on the intake manifold

(Fig. 28) or (Fig. 29). Fuel does not enter the intake
manifold through the throttle body. Fuel is sprayed
into the manifold by the fuel injectors.

OPERATION

Filtered air from the air cleaner enters the intake

manifold through the throttle body. The throttle body
contains an air control passage controlled by an Idle
Air Control (IAC) motor. The air control passage is
used to supply air for idle conditions. A throttle valve
(plate) is used to supply air for above idle conditions.

Certain sensors are attached to the throttle body.

The accelerator pedal cable, speed control cable are
connected to the throttle body cam.

Fig. 28 IAC VALVE 2.4L

1 - Idle Air Control Valve
2 - Throttle Position Sensor

Fig. 29 IAC VALVE LOCATION 3.3/3.8L

1 - Idle Air Control Valve
2 - Throttle Position Sensor

FUEL INJECTION

14 - 39

O2 SENSOR (Continued)

A (factory adjusted) set screw is used to mechani-

cally limit the position of the throttle body throttle
plate. Never attempt to adjust the engine idle
speed using this screw. All idle speed functions are
controlled by the PCM.

REMOVAL

(1) Disconnect negative cable from battery cable.
(2) Remove air inlet to throttle body hose clamp.
(3) Remove throttle and the speed control (if

equipped) cables from lever and bracket.

(4) Disconnect electrical connectors from the idle

air control motor and throttle position sensor (TPS)
(Fig. 28) or (Fig. 29).

(5) Remove

throttle

body

intake

manifold

attaching bolts.

(6) Remove throttle body and gasket.

INSTALLATION

(1) Install a new gasket, if required.
(2) Install throttle body.
(3) Tighten throttle body mounting bolts. The 2.4L

to 28.2 N·m (250 ±50 in. lbs.) torque, The 3.3/3.8L to
11.6 N·m (105 ±20 in. lbs.) torque.

(4) Connect electrical connectors to the idle air

control motor and throttle position sensor (TPS) (Fig.
28) or (Fig. 29).

(5) Install air inlet to throttle body hose clamp and

tighten.

(6) Connect negative cable to battery cable.

THROTTLE CONTROL CABLE

REMOVAL

(1) Working from the engine compartment, hold

the throttle body throttle lever in the wide open posi-
tion.

(2) Remove the throttle cable from the throttle

body cam.

(3) From inside the vehicle, hold up the pedal and

remove the cable retainer and throttle cable from the
upper end of the pedal shaft.

(4) Remove retainer clip from throttle cable and

grommet at dash panel.

(5) From the engine compartment, pull the throttle

cable and gromment out of the dash panel.

(6) Remove the throttle cable from throttle bracket

by carefully compressing both retaining ears simulta-
neously then gently pull the throttle cable from
throttle bracket or if it is the slide snap design you
have to slide the locking tab out of the hole and then
slide the cable assembly out of the bracket.

INSTALLATION

(1) From the engine compartment, push the hous-

ing end fitting and grommet into the dash panel.In-
stall gromment into the dash panel.

(2) Install the cable housing (throttle body end)

into the cable mounting bracket on the engine.

(3) From inside the vehicle, hold up the pedal and

install throttle cable and cable retainer in the upper
end of the pedal shaft.

(4) At the dash panel, install the cable retainer

clip between the end of the throttle cable fitting and
grommet

(5) From the engine compartment, rotate the

throttle lever wide open and install the throttle
cable.

THROTTLE POSITION SENSOR

DESCRIPTION

The throttle position sensor mounts to the side of

the throttle body (Fig. 30) or (Fig. 31).The sensor
connects to the throttle blade shaft. The TPS is a
variable resistor that provides the Powertrain Con-
trol Module (PCM) with an input signal (voltage).

Fig. 30 Throttle Position Sensor—2.4L Engine

1 - Idle Air Control Valve
2 - Throttle Position Sensor

14 - 40

FUEL INJECTION

THROTTLE BODY (Continued)

Content .. 978 979 980 981 ..