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:
Changing audio source
1 Press the “AUDIO” button to display the audio source selection screen.
If the audio source selection screen is not displayed, press the “AUDIO” button
again.
2 Select the desired audio source.
1 Select the desired audio source then
or
to reorder.
...
Terminals of ecu
Oscilloscope wave (*1)
Hint:
terminal: od – gnd
gauge set: 5 v / div, 50 ms / div
condition: during cruise control driving o/d switch on.
...
Wiring diagram
1 Inspect terminal voltage(pi)
(a) turn
Turn the ignition switch to on.
measure voltage between terminal 5 (pi) of cruise control
ecu assy and body ground, when the cruise control main
switch button is on and off.
Ok:
2 Inspect combination meter assy
3 Check harn ...


