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:
Cleaning and protecting the vehicle exterior
Perform cleaning in a manner
appropriate to each
component and its material.
Cleaning instructions
Working from top to bottom,
liberally apply water to the
vehicle body, wheel wells and
underside of the vehicle to
remove any dirt and dust.
Wash the vehicle body using
a sponge or soft cloth, ...
Using the AUX port
To use the AUX port, connect a portable player, press the “AUDIO” button,
then select “AUX” to display the audio control screen.
Connecting a portable audio player
■Operating portable audio players connected to the multimedia system
The volume can be adjusted using the vehicle' ...
Circuit description
Refer to dtc p0115
Dtc no.
Dtc detection condition
Trouble area
P0125
If the engine coolant temperature (ect) was less than –6.6 °C
(20 °F) when starting the engine, and 20 minutes after the engine
start, the ect sensor still indicates below 20 °C (68 ...


