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:
Driving
► Automatic transmission or continuously
variable transmission
1 With the brake pedal depressed, shift the shift lever to D.
(, 174, 176)
2 Release the parking brake.
3 Gradually release the brake pedal and gently depress the accelerator pedal to
accelerate the vehicle.
► ...
If you think something is wrong
If you notice any of the following symptoms, your vehicle probably needs adjustment
or repair. Contact your Toyota dealer as soon as possible.
Visible symptoms
● Fluid leaks under the vehicle.
(Water dripping from the air conditioning after use is normal.)
● Flat-looking tires or u ...
Inspection procedure
1 Inspect stop lamp switch assy
2 Check harness and connector(stop lamp switch assy – ecm)
Install the stop lamp switch assy.
disconnect the ecm connector.
measure the voltage according to the value(s) in the table
below when the brake pedal is depressed and rele ...


