Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Cruise control system / Idle signal circuit / Circuit description
Toyota Corolla (E120): Circuit description
When the idle switch is turned on, a signal is sent to the cruise control ecu assy. The cruise control ecu assy uses this signal to correct the discrepancy between the throttle valve position and the actuator position sensor values to enable accurate cruise control at the set speed. If the idle switch is malfunctioning, problem symptoms also occur in the engine, so also inspect the engine.

Wiring diagram

Other materials:
Circuit description
Refer to dtc p0120
Dtc no.
Dtc detection condition
Trouble area
P0121
The following condition is met 4 times. After the vehicle speed
has exceeded 19 mph (30 km/h) once, the throttle position
sensor output value is out of normal range when the throttle
...
Engine oil
With the engine at operating temperature and turned off, check the oil level
on the dipstick.
■ Checking the engine oil
1 Park the vehicle on level ground. After warming up the engine and turning it
off, wait more than 5 minutes for the oil to drain back into the bottom of the engine.
2 ...
Inspection procedure
1 Check side squib(rh) circuit(airbag sensor assy center – front
seat airbag assy rh)
Disconnect the negative (–) terminal cable from the battery,
and wait at least for 90 seconds.
disconnect the connectors between the airbag sensor
assy center and the front seat airbag assy ...


