Toyota Corolla (E120): 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 air–fuel ratio was lean or rich, etc. At the time of the malfunction.
1 Check other dtc output(in addition p0121)
- Connect the hand–held tester or the obd ii scan tool to the dlc3.
- turn the ignition switch on and push the hand–held tester or the obd ii scan tool main switch on.
- select the item ”diagnosis / enhanced obd ii / dtc info / current codes”.
- read the dtcs.
Result:

Hint
: if any other codes besides p0121 is output, perform the troubleshooting for those dtcs first.


Go to relevant dtc chart
Other materials:
Dtc check/clear
Notice:
if there is no dtc in the normal mode, check the pending
fault code using the continuous test results
function (mode 7 for sae j1979) on the obd ii scan
tool or the hand–held tester.
Hand–held tester only:
when the diagnosis system is switched from the normal
mode to the ...
Automatic transaxle assy (atm)
Precaution
The automatic transaxle is composed of highly precision–finished
parts, necessitating careful
inspection before reassembly because even a small nick could cause fluid
leakage or affect
the performance. The instructions here are organized so that you work on
only o ...
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 ...


