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:
Pre–check
1. Diagnosis system
Release the parking brake lever.
check the warning lights.
When the ignition switch is turned on, check that the abs
warning light and brake warning light goes on for 3 sec.
Hint:
when the parking brake is applied or the level of the brake
fluid is low, the ...
Inspection procedure
1 Check wire harness(dlc3 – airbag sensor assy center)
Turn the ignition switch to the lock position.
disconnect the aribag sensor assy center connector.
measure the resistance according to the value(s) in the
table below.
Standard:
2 Check wire harness(cg of dl ...
Inspection procedure
1 Check hazard warning signal switch assy
Check the hazard warning switch continuity, as shown in
the illustration and table.
Standard:
2 Check turn signal flasher assy
3 Check wire harness (tvip ecu turn signal flasher)
Disconnect the tvip ecu and turn signal flashe ...


