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:
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 ...
Fuel information
You must only use unleaded gasoline in your vehicle.
Select octane rating 87 (Research Octane Number 91) or higher.
Use of unleaded gasoline with an octane rating lower than 87 may result in engine
knocking. Persistent knocking can lead to engine damage.
At minimum, the gasoline you use should ...
Power steering
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