Air Temperature Sensor Cover to Intake Manifold BMW 528i 1997 E39 Workshop Manual

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Fuel Injection
CAUTION-
Be sure ignition is OFF before disconnecting or reconnecting
DME system components.
Remove engine coolant temperature sensor:
Unclip crankcase vent hose
(C) from cylinder head cover.
Remove plastic cover
(6) from atop intake manifold run-
ners.
Working under front of intake manifold, disconnect ECT
harness.
Unscrew ECT sensor
(C) from cylinder head.
Installation is reverse of removal:
Use new copper sealing washers when installing sensor.
Replace any engine coolant lost.
Tightening torque
Temperature sensor to cylinder head
13 Nm (10 it-lb)
Intake air temperature ([AT) sensor,
testing and replacing
4 The intake air temperature (IAT) sensor (arrow) signal is
used by the ECM to monitor intake air temperature for fuel
and
igntion adaptation. The sensor is .ocared in rne 'ntane
man:lold behind the throttle housng.
The ECM monitors an applied voltage (5 vdc) to the sensor
The voltage drop across the sensor varies as the intake air
temperature (sensor resistance) changes.
NOJE-
The IATsensor is an NTC (negative temperature coefficient)
type sensor. In other words, as the temperature rises, resis-
tance through the sensor decreases.
If the IAT sensor input is implausible, a
fault code is set.The
MIL is illuminated when OED II fault criteria are exceeded.
The ECM then operates the engine using only the engine
coolant temperature (ECT) sensor input.
The intake air temperature sensor can be tested using a
mul-
timeter across its terminals:
/ IAT sensor resistance @ 20" C (68°F) / 2.2 - 2.7 lkCk
~ -- ~~ -
CAUTION--
Be sure ignition is
OFFbefore disconnecting or reconnecting
DME system components.

Downloaded from www.Manualslib.com manuals search engine
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 I1 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.
lid I The IATsensor can be tested using a multimeter:
/IAT sensor resistance at 20'C (68°F) 2.2 - 2.7 kd
Remove engine cover by prying off plastic trim caps (arrows)
and removing nuts below caps.