Toyota Corolla (E120): Diagnostic trouble code chart

Pre–check

Terminals of ecu

Other materials:

If the electronic key does not operate properly (vehicles with a smart key system)
If communication between the electronic key and vehicle is interrupted or the electronic key cannot be used because the battery is depleted, the smart key system and wireless remote control cannot be used. In such cases, the doors can be opened and the engine can be started by following the procedur ...

How to proceed with troubleshooting
The hand–held tester can be used at step 4, 6, 8 and 9. 1 Vehicle brought to workshop 2 Customer problem analysis 3 Warning light check 4 The dtcs check (present and past dtcs) 5 The dtcs chart 6 Circuit inspection 7 Repair 8 Clear the dtcs (present and past dtcs) 9 The dt ...

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 ...