Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Crankshaft position sensor ”a”
circuit / Circuit description
Toyota Corolla (E120): Circuit description
The crankshaft position sensor (ne signal) consists of a magnet, iron core and pickup coil.
The ne signal plate (crankshaft position sensor plate) has 34 teeth and is installed on the crankshaft. The ne signal sensor generates 34 signals for each engine revolution. This sensor monitors a plate (timing rotor) located on the crankshaft timing pulley and is used by the ecm to detect crankshaft angle and engine speed (rpm/ne). As the crankshaft timing pulley rotates through an engine revolution, this sensor communicates the rotation of the ne signal plate as a pulse signal to the ecm. Based on the signal, the ecm controls fuel injection time and ignition timing.
Reference: inspection using the oscilloscope.
Hint
: the correct waveform is as shown on the left.
Monitor description
If there is no signal from the crankshaft sensor despite the engine revolving, the ecm interprets this as a malfunction of the sensor.
Monitor strategy
Typical enabling conditions
Typical malfunction thresholds
Wiring diagram
Other materials:
For vehicles equipped with srs airbag and seat belt pretensioner
Hint:
the vehicle is equipped with an srs (supplemental restraint system), such as the
horn button assembly,
the instrument panel passenger airbag assembly, the front seat airbag assembly,
the center airbag sensor
assembly, the front airbag sensor, the side airbag sensor and the seat belt
p ...
Cooling
Preparation
Recomended tools
Equipment
Coolant
...
Inspection procedure
1 Check d squib circuit(airbag sensor assy center – horn button
assy)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the horn button assy
and the airbag sensor assy center.
for the oran ...