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 cooling system
- Check that there is a defect in the cooling system which causes overcool, such as abnormal radiator fan operation, modified cooling system and so on.


2 Inspect thermostat


3 Check other dtc output(in addition to dtc p0128)
- 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 p0128 is output, perform the troubleshooting for those dtcs first.


Replace ecm
Other materials:
Hood
Opening the hood
1. Pull the hood lock release
lever.
The hood will pop up slightly.
2. Pull the auxiliary catch lever
to the left and lift the hood.
3. Hold the hood open by inserting
the support rod into the
slot.
WARNING
■Pre-driving check
Check that the hood is fully closed
and locked.
If ...
Checking and replacing fuses
If any of the electrical components do not operate, a fuse may have blown.
If this happens, check and replace the fuses as necessary.
1 Turn the engine switch off.
2 Open the fuse box cover.
► Engine compartment
Push the tab in and lift the lid off.
► Under the driver’s side i ...
Replacement
1. Remove engine under cover rh
2. Drain coolant
3. Remove front wheel rh
4. Remove cylinder head cover no.2
Remove the 2 nuts, 2 clips and cylinder head cover.
5. Remove fan and generator v belt
Turn the v–ribbed belt tensioner slowly clockwise and
loosen it. Then, remove ...


