Intake Air Temperature (Iat) Sensor; Testing And Replacing - BMW 5251 Service Manual

Fuel Injection
-
Installation is reverse of removal:
Use new copper sealing washers when installing sensor.
Replace any lost coolant.
Tightening torque
Temperature sensor to cylinder head
13
Nm
(10
ft-lb)
Intake air temperature (IAT) sensor,
testing and replacing
4
The intake airtemperature (IAT) sensor, located at the top of
I
the intake manifold, adapts (fine tunes) the fuel mixture and
i
T
engine timing based on varying intake air temperatures.
i
If the intaite air temperature signal is implausible, a fault code
!
is set and the MIL is illuminated when OBD I 1 fault criteria are
I
exceeded. The ECM then operates the engine using the ECT
i
sensor sional inout as a back uo.
type sensor. In other words, a > the temperature rises, resis-
tance through the sensor decreases.
l i d
I
The IATsensor can be tested using a multimeter:
/IAT sensor resistance at 2 0 ' C
(68°F)
2.2
-
2.7 k d
Remove engine cover by prying off plastic trim caps (arrows)
and removing nuts below caps.