Intake Air Temperature Sensor - Jeep KJ 2005 Service Manual

KJ
IDLE AIR CONTROL MOTOR (Continued)
REMOVAL
2.4L
The Idle Air Control (IAC) motor is located on the
rear side of the throttle body (Fig. 12).
(1) Disconnect electrical connector from IAC motor.
(2) Remove two mounting bolts (screws).
(3) Remove IAC motor from throttle body.
Fig. 12 TPS/IAC MOTOR - 2.4L
1 - THROTTLE POSITION SENSOR (TPS)
2 - MOUNTING SCREWS
3 - IDLE AIR CONTROL MOTOR (IAC)
4 - MOUNTING SCREWS
3.7L
The Idle Air Control (IAC) motor is located on the
side of the throttle body (Fig. 13).
(1) Disconnect electrical connector from IAC motor.
(2) Remove two mounting bolts (screws).
(3) Remove IAC motor from throttle body.
INSTALLATION
2.4L
The Idle Air Control (IAC) motor is located on the
rear side of the throttle body.
(1) Install IAC motor to throttle body.
(2) Install and tighten two mounting bolts (screws)
to 7 N·m (60 in. lbs.) torque.
(3) Install electrical connector.
3.7L
The Idle Air Control (IAC) motor is located on the
side of the throttle body (Fig. 13).
(1) Install IAC motor to throttle body.
(2) Install and tighten two mounting bolts (screws)
to 7 N·m (60 in. lbs.) torque.
FUEL INJECTION - 2.4L/3.7L GAS
Fig. 13 TPS/IAC MOTOR - 3.7L
1 - THROTTLE POSITION SENSOR (TPS)
2 - MOUNTING SCREWS
3 - IDLE AIR CONTROL MOTOR (IAC)
4 - MOUNTING SCREWS
(3) Install electrical connector.
INTAKE AIR TEMPERATURE
SENSOR
DESCRIPTION
The 2–wire Intake Manifold Air Temperature (IAT)
sensor is installed in the intake manifold with the
sensor element extending into the air stream.
The IAT sensor is a two-wire Negative Thermal
Coefficient (NTC) sensor. Meaning, as intake mani-
fold temperature increases, resistance (voltage) in the
sensor decreases. As temperature decreases, resis-
tance (voltage) in the sensor increases.
OPERATION
The IAT sensor provides an input voltage to the
Powertrain Control Module (PCM) indicating the
density of the air entering the intake manifold based
upon intake manifold temperature. At key-on, a
5–volt power circuit is supplied to the sensor from
the PCM. The sensor is grounded at the PCM
through a low-noise, sensor-return circuit.
The PCM uses this input to calculate the following:
• Injector pulse-width
• Adjustment of spark timing (to help prevent
spark knock with high intake manifold air-charge
temperatures)
The resistance values of the IAT sensor is the same
as for the Engine Coolant Temperature (ECT) sensor.
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