Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Cruise control system / Stop light switch circuit / Circuit description
Toyota Corolla (E120): Circuit description
When the brake pedal is depressed, the stop lamp switch assy sends a signal to the cruise control ecu assy.
When the cruise control ecu assy receives this signal, it cancels the cruise control.
A fail–safe function is provided so that cancel functions normally, even if there is a malfunction in the stop light switch circuit.
The cancel conditions are: battery positive voltage at terminal stp–.
When the brake pedal is depressed, normal battery positive voltage normally is applied through the stop fuse and stop lamp switch assy to terminal stp– of the cruise control ecu assy, and the cruise control ecu assy turns the cruise control to off.
If the harness connected to terminal stp– has an open circuit, terminal stp– will have battery positive voltage and the cruise control will be turned off.
Also, when the brake pedal is depressed, the magnetic clutch circuit is cut mechanically by the stop lamp switch assy, turning the cruise control off.
Wiring diagram

Other materials:
If the shift lever cannot be shifted from P (except vehicles with a manual transmission)
If the shift lever cannot be shifted with your foot on the brake pedal, there
may be a problem with the shift lock system (a system to prevent accidental operation
of the shift lever). Have the vehicle inspected by your Toyota dealer immediately.
The following steps may be used as an emergency ...
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 ...
Oil filter sub–assy
Replacement
Caution:
prolonged and repeated contact with mineral oil will result in the
removal of natural fats from
the skin, leading to dryness, irritation and dermatitis. In addition, used
engine oil contains potentially
harmful contaminants which may cause skin cancer.
Exercise ...


