Service Manual

3.17
ELECTRONIC FUEL INJECTION
3
TEMP / MANIFOLD ABSOLUTE
PRESSURE SENSOR (T-MAP)
Operation Overview
Mounted on the (IAFM), the temperature and manifold absolute
pressure sensor (T-MAP) performs two functions in one unit.
Air passing through the intake is measured by the T-MAP and
relayed to the ECU. These signals, comprised of separate air
temperature and manifold absolute pressure readings, are
processed by the ECU and compared to its programming for
determining the fuel and ignition requirements during
operation.
T-MAP Test
The temperature and manifold absolute pressure sensor
(T-MAP) is a non-serviceable item. If it is faulty, it must be
replaced. This sensor requires a 5 Vdc input to operate, therefore
the T-MAP sensor should only be tested using the Digital
Wrench™ Diagnostic Software (dealer only).
T-MAP Replacement
1. Disconnect the sensor from the main harness.
2. Using a 10 mm wrench, remove the retaining bolt and
sensor.
3. Install the new sensor using a light coating of oil on the O-
ring to aid installation.
4. Torque the retaining bolt to specification.
IDLE AIR CONTROL VALVE (IAC)
Operation Overview
The Idle Air Control (IAC) is used to stabilize the idle quality of
the engine at cold start-up and after warm-up operations.
Mounted in front of the engine, the IAC contains 1 stepper motor
which receives varying voltage signal pulses from the ECU.
These pulses determine the IAC plunger setting, thereby
controlling the amount of air bypassing the closed throttle body
for idle control. If the IAC is disconnected or inoperative, it will
remain at it’s last operated position.
IAC Test
The IAC is a non-serviceable item. If it is faulty, it must be
replaced. It can be ‘bench tested’ using the following method:
Set your meter to read Ohms. Check the resistance values at
each of the following pin locations of the IAC. If any of the
readings are out of specification, replace the IAC
= T
T-MAP Retaining Bolt Torque:
35-53 in. lbs. (4-6 Nm)
T-MAP
IAC Resistance Readings
Pins Resistance Pins Resistance
1 - 2 30Ω ± 1.2Ω 4 - 5 30Ω ± 1.2Ω
2 - 3 30Ω ± 1.2Ω 5 - 6 30Ω ± 1.2Ω
1 - 3 60Ω ± 2.4Ω 4 - 6 60Ω ± 2.4Ω
IAC
1
2
3
4
5
6
IAC Valve Connector