Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Electronic controlled automatic transaxle / O/d main switch circuit / Circuit description
Toyota Corolla (E120): Circuit description
The o/d main switch (transmission control switch) is a momentary type switch. When pressing the o/d main switch, the o/d off indicator light lights up and the ecm prohibits shifting into o/d, and when pressing it once again, the o/d off indicator light goes off and the ecm allows shifting into o/d. Turning the ig switch off will reset the o/d off indicator light.
Wiring diagram
Other materials:
Circuit description
While driving uphill with cruise control activated, in order to minimize gear
shifting and provide smooth cruising
overdrive may be prohibited temporarily under some conditions.
The cruise control ecu sends o/d cut signals to the ecm as necessary and the ecm
cancels overdrive
shifting until ...
Have the malfunction repaired immediately. (vehicles with a smart key system)
After taking the specified steps to correct the suspected problem, check that
the warning message and light go off.
■Warning buzzer ...
Circuit description
The ecm compares the two waveforms of the heated oxygen sensors located
before and after the catalyst
to determine whether or not the catalyst performance has deteriorated.
Air–fuel ratio feedback compensation keeps the waveform of the heated oxygen
sensor in front of the catalyst
alterna ...