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:
Monitor description
The battery supplies electricity to the ecm even when the ignition switch is
off. This electricity allows the
ecm store data such as dtc history, freeze frame data, fuel trim values, and
other data. If the battery voltage
falls below a minimum level, the ecm will conclude that there is a fault ...
How to proceed with troubleshooting
1 Vehicle brought to workshop
2 Customer problem analysis
3 Problem symptom confirmation
4 Circuit inspection
5 Repair or replace
6 Confirmation test
7 End
Customer problem analysis check
...
Trip information
■ Switching the display
Items displayed can be switched by pressing the display change button.
■ Odometer
Displays the total distance the vehicle has been driven.
■ Trip meter A/trip meter B
Displays the distance the vehicle has been driven since the meter was last reset.
...


