Toyota Corolla (E120) 2002–2008 Repair Manual / Introduction / How to troubleshoot ecu controlled
systems / Circuit inspection
Toyota Corolla (E120): Circuit inspection
How to read and use each page is shown below.

Other materials:
Circuit description
The fuel trim is related to the feedback compensation value, not to the basic
injection time. The fuel trim includes
the short–term fuel trim and the long–term fuel trim.
The short–term fuel trim is the short–term fuel compensation used to maintain
the air–fuel ratio at stoichiomet ...
On–vehicle inspection
1. Inspect for electrical door lock operation
Hint:
w/ power window:
the door control switch is built in the master switch in the driver’s door
and also in the passenger’s
door.
W/o power window:
the door control switch is in the driver’s door and also in the passenger’s
d ...
Warning lights
Warning lights inform the driver of malfunctions in the indicated vehicle’s systems.
*1: Vehicles without a smart key system:
These lights turn on when the engine switch is turned to the “ON” position to indicate
that a system check is being performed. They will turn off after the engi ...


