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:
Monitor description
The battery supplies electricity to the ecm even when the ignition switch is
off. This electricity allows the
ecm store data such as dtc history, freeze frame data, fuel trim values, and
other data. If the battery voltage
falls below a minimum level, the ecm will conclude that there is a fault ...
Problem symptoms table
The suspected circuits or parts for each problem symptom are shown in the
table below. Use this table to
troubleshoot the problem when a normal code is displayed in the diagnostic
trouble code chart but the problem
is still occurring. Numbers in the table indicate the order in which the
circ ...
For vehicles equipped with catalytic converter
Caution:
if large amount of unburned fuel flows into the converter, it may cause
overheating and a fire hazard.
To prevent this, observe the following precautions.
Use only unleaded gasoline.
avoid prolonged idling.
Avoid running the engine at idle speed for more than 20 minutes. ...


