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:
Fuel information
You must only use unleaded gasoline in your vehicle.
Select octane rating 87 (Research Octane Number 91) or higher.
Use of unleaded gasoline with an octane rating lower than 87 may result in engine
knocking. Persistent knocking can lead to engine damage.
At minimum, the gasoline you use should ...
Circuit description
In the diagram below, when the engine is cranked, current flows from terminal
st2 of the ignition switch to
the starter relay coil and also current flows to terminal sta of the ecm (sta
signal).
When the sta signal and ne signal are input to the ecm, tr is turned on, current
flows to the c ...
Checking the engine coolant
The coolant level is satisfactory
if it is between the "MAX" and
"MIN" lines on the reservoir
when the engine is cold.
Reservoir
"MAX" line
"MIN" line
If the level is on or below the "MIN"
line, add coolant up to the "MAX"
line.
■Coolant selection
Only use "Toyota Super Long Life
Coolant" or ...


