Toyota Corolla (E120): How to troubleshoot ecu controlled systems

Vehicle lift and support locations

General information

Other materials:

Inspection procedure
Hint: read freeze frame data using the hand-held tester or the obd ii scan tool. Freeze frame data records the engine conditions when a malfunction is detected. When troubleshooting, it is useful for determining whether the vehicle was running or stopped, the engine was warmed up or not, the ...

Abbreviations used in this manual
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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 ...