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:
Inspection procedure
Hint:
read freeze frame data using the hand-held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, the ...
System description
The ecm uses signals from the vehicle speed sensor and crankshaft position
sensor to detect the actual
gear position (1st, 2nd, 3rd or o/d gear).
Then the ecm compares the actual gear with the shift schedule in the ecm memory
to detect the mechanical
trouble of the shift solenoid valves, th ...
What to do if... (Troubleshooting)
If there is a problem with the hands-free system or a Bluetooth® device, first
check the table below.
► When using the hands-free system with a
Bluetooth® device
► When registering/connecting a cellular
phone
► When making/receiving a call
► When using the p ...


