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:
If your vehicle has to be stopped
in an emergency
Only in an emergency, such
as if it becomes impossible
to stop the vehicle in the
normal way, stop the vehicle
using the following procedure:
Stopping the vehicle
1. Steadily step on the brake
pedal with both feet and
firmly depress it.
Do not pump the brake pedal
repeatedly as this will increase t ...
Seat heaters
Press the switch.
1 High temperature
2 Low temperature
The indicator light comes on when the switch is on.
■The seat heaters can be used when
► Vehicles without a smart key system
The engine switch is in the “ON” position.
►Vehicles with a smart key system
The engine ...
How to proceed with troubleshooting
Hint:
carry out troubleshooting in accordance with the procedures on the following
page. Here, only the basic
procedures are shown. Details are provided in the diagnostics section, showing
the most effective methods
for each circuit. Confirm the troubleshooting procedures first for the releva ...


