Toyota Corolla (E120): Instrument panel/meter

On–vehicle inspection

Instrument panel sub–assy lower

Other materials:

Circuit description
The rotary solenoid type idle air control (iac) valve is located under the throttle body and intake air bypassing the throttle valve flows into the iac valve through the passage. In this way the intake air volume bypassing the throttle valve is regulated, controls the engine speed. The ...

Inspection procedure
Hint: hand–held tester only: narrowing down the trouble area is possible by performing ”a/f control” active test (heated oxygen sensor or other trouble areas can be distinguished). Perform active test using hand–held tester (a/f control). Hint: ”a/f control” is the active te ...

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 ...