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:
Key confinement prevention function does not work
properly (unlock warning switch circuit)
Circuit description
The unlock warning switch turns on when the key is inserted in the ignition
key cylinder and the door courtesy
switch turns on when the driver’s door is opened, and the integration relay
monitors both switches conditions.
According to these switches conditions, the int ...
Inspection procedure
1 Inspect transmission wire(sl)
Disconnect the transmission wire connector from the
transaxle.
measure the resistance according to the value(s) in the
table below.
Standard:
2 Check harness and connector(transmission wire – ecm)
Connect the transmission wire c ...
Inspection procedure
Hint:
read freeze frame data using the hand-held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, the ...