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:
Replacement
Hint: components:
1. Remove radiator grille sub–assy
2. Remove front bumper cover
3. Remove lh headlamp assy
Remove the 3 bolts.
pull out the headlight assy lh forward, then disconnect
the bracket of body side.
Release the claws and disconnect the connectors as
sh ...
Precaution
1. Precaution of headlight bulb replacement
if even a thin film of oil is left on the surface of the halogen
lamp, its service life will be shortened because
the lamp will be burn at a higher temperature.
handle any halogen lamp with great care. Dropping, hitting or
damagin ...
Light control switch circuit
Wiring diagram
Inspection procedure
1 Check headlamp dimmer switch assy (light control switch)
2 Check wire harness (tvip ecu light control switch)
Disconnect the tvip ecu and light control switch connectors.
check the continuity between the terminals of the tvip
e ...


