Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Sfi system / Throttle/pedal position
sensor/switch ”a” circuit
range/performance problem
Toyota Corolla (E120): Throttle/pedal position sensor/switch ”a” circuit range/performance problem
Dtc p0121 throttle/pedal position sensor/switch ”a” circuit range/performance problem
Hint
: this is the purpose of the ”throttle position sensor”.
Other materials:
On–vehicle inspection
1. Inspect cooling system for leaks
Caution:
to avoid the danger of being burned, do not remove the radiator
cap while the engine and radiator are still hot, as fluid
and steam can be blown out under pressure.
fill the radiator with coolant and attach a radiator cap tester.
  ...
Wireless remote control
(if equipped)
The keys are equipped with the
following wireless remote control:
Vehicles without a smart key
system
Locks the doors
Unlocks the doors
Opens the windows*1 and
moon roof*1, 2
Opens the trunk
Sounds the alarm
Vehicles with a smart key system
Locks the doors
Unlocks the doors
Opens the ...
Circuit description
When the ignition switch is turned on, battery positive voltage is applied to
the coilwhich closes the contacts
of the efi main relay (marked: efi) and supplies power to terminal +b of the ecm.
This signal causes current to flow to the coil, closing the contacts of the efi
relay and supplyin ...


