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:
Replacement
Hint:
installation is in the reverse order of the removal. But the installation is
indicated only when it has a point.
1. Remove luggage compartment door cover
2. Remove rear spoiler
remove the 2 screws.
disconnect the wire harness connector.
put protective tape.
&nb ...
If a warning message or indicator is displayed (vehicles with a multi-information
display)
If a warning is shown on the multi-information display, stay calm and perform
the following actions:
1 Master warning light
The master warning light also comes on or flashes in order to indicate that a message
is currently being displayed on the multiinformation display.
2 Multi-information d ...
Circuit description
When the ignition switch is turned on, battery positive voltage is applied to
the coilwhich closes the contacts
of the efi main relay (marked: efi) and supplies power to terminal +b of the ecm.
This signal causes current to flow to the coil, closing the contacts of the efi
relay and supplyin ...


