Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / Toyota vehicle intrusion protection system / Ignition switch circuit / Circuit description
Toyota Corolla (E120): Circuit description
If the ignition switch is turned to the on position, battery positive voltage is applied to the switches, such as terminal ig of the ecu.
Wiring diagram

Other materials:
Inspection procedure
1 Check fuse(ecu–ig)
Remove the ecu–ig fuse from the instrument panel j/b.
check the continuity of the ecu–ig fuse.
Ok: continuity
2 Inspect terminal voltage(b)
Remove the cruise control ecu assy with connector still
connected.
turn the ignition switch ...
Overhaul
Notice: when installing, coat the parts indicated by the arrow with
power steering fluid or molybdenum disulfide lithium base grease.
1. Precaution
2. Disconnect battery negative terminal
3. Inspect center front wheel
4. Remove horn button assy
5. Remove steering wheel assy
sst 09950–50013 ...
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 ...


