Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / ABS with EBD system / Right/Left front speed sensor circuit / Circuit description
Toyota Corolla (E120): Circuit description

The speed sensor detects wheel speed and transmits the appropriate signals to the ecu. These signals are used for control of the abs control system. Each of the front and rear rotors has 48 serrations.
When the rotors rotate, the magnetic field generated by the permanent magnet in the speed sensor induces an ac voltage.
Since the frequency of this ac voltage changes in direct proportion to the speed of the rotor, the frequency is used by the ecu to detect the speed of each wheel.

Hint
: Dtc no. C0200/31 and c1235/35 is the right front speed sensor.
Dtc no. C0205/32 and c1236/36 is the left front speed sensor.
Wiring diagram

Other materials:
Inspection procedure
1 Check low pitched horn assy
Connect the positive (+) lead from the battery to the terminal
and negative (–) lead to the horn body, and check that
the horn blows.
2 Check relay (marking: horn)
Remove the relay from the engine room j/b.
check the horn relay conti ...
Circuit description
Refer to dtc p0130
Hint:
the ecm provides a pulse width modulated control circuit to adjust current
through the heater. The heated
oxygen sensor heater circuit uses a relay on the b+ side of the circuit.
Monitor description
The ecm uses the heated oxygen sensor information to regulate t ...
Precaution
Caution:
the corolla is equipped with srs, which comprises a driver airbag,
front passenger airbag
and side airbag. Failure to carry out service operations in the correct
sequence could cause
the srs to unexpectedly deploy during servicing, possibly leading to a
serious accident. Fu ...


