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:
Gauges and meters (multi-information display)
The displayed content may differ depending on the type of meter.
1 Tachometer
Displays the engine speed in revolutions per minute.
2 Speedometer
3 Fuel gauge
4 Multi-information display
The multi-information display presents the driver with a variety of drivingrelated
data including the cu ...
Tire pressure warning system (if equipped)
Your vehicle is equipped with a tire pressure warning system that uses tire pressure
warning valves and transmitters to detect low tire inflation pressure before serious
problems arise.
◆ Installing tire pressure warning valves and transmitters
When replacing tires or wheels, tire press ...
Inspection procedure
1 Check fuse(ecu–ig)
Remove the ecu–ig fuse from the instrument panel j/b.
check the continuity of the ecu–ig fuse.
Ok: continuity
2 Inspect terminal voltage(b)
Remove the cruise control ecu assy with connector still
connected.
turn the ignition switch ...


