Toyota Corolla (E120) 2002–2008 Repair Manual / Diagnostics / ABS with EBD system / Malfunction in abs ecu / Circuit description
Toyota Corolla (E120): Circuit description

Hint
: there is a case that hand–held tester cannot be used when ecu is abnormal.
Wiring diagram

Other materials:
Things you should know
■ If you notice any symptoms
If you notice any of the following symptoms, refer to the likely cause and the
solution, and re-check.
If the symptom is not resolved by the solution, have the vehicle inspected by
your Toyota dealer.
CAUTION
■When using the rear view monitor system ...
Floor shift cable transmission control
shift (atm)
Replacement
1. Precaution
2. Disconnect battery negative terminal
3. Remove parking brake hole cover sub–assy
4. Remove console panel upper
5. Remove console box carpet
6. Remove console box sub–assy rear
7. Remove air bag sensor assy center
8. Disconnect oxygen sensor connector
...
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 ...


