Toyota Corolla (E120): Check and replace ecu
Notice
: start an inspection of the connector from the backside of the connector on the wire harness side with the connector connected to the ecu.
When no measurement condition is specified, perform the inspection with the engine stopped and also the ignition switch on.
- First check the ecu ground circuit. If it is faulty, repair it.
If it is normal, the ecu could be faulty. In this case, replace the ecu with one that functions normally and check if the symptoms appear.
- Measure the resistance between the ecu ground
terminal and body ground.
Resistance: 1 Ω or less

- Disconnect the ecu connector, check the ground terminals on the ecu side and wire harness side for bends and check the contact pressure.

Other materials:
Manual air conditioning system∗
Air conditioning controls
► Heater
► Air conditioning system
■ Adjusting the temperature setting
► Heater
To adjust the temperature setting, turn the
dial clockwise to increase the temperature.
► Air conditioning system
To adjust the temperature setting, tu ...
Audio system types
► Without Multimedia system
► With Multimedia system
► With navigation system
Owners of models equipped with a navigation system should refer to the “Navigation
System Owner's Manual”.
■Using cellular phones
Interference may be heard through the audio system ...
On–vehicle inspection
1. Inspect pressure switch no.1.
Magnetic clutch control:
inspect pressure switch operation.
Set on the manifold gauge set.
Connect the positive (+) lead from the ohmmeter to
terminal 4 and the negative (–) lead to terminal 1.
Check continuity between termin ...


