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:
Adjustment
1. Inspect park/neutral position switch assy
apply the parking brake and turn the ignition switch on.
depress the brake pedal and check that the engine starts only when
the shift lever is set in n or p position
and it does not start in the other position.
check that th ...
Inspection
1. Cooler thermistor no.1
Check resistance between terminals 1 and 2 of cooler
thermistor no. 1 At each temperature, as shown in the
chart.
Resistance:
If resistance value is not as specified, replace the sensor.
2. Cooler and accessory assy
Inspect blower switch contin ...
On–vehicle inspection
1. Inspect drive belt
Visually check the belt for excessive wear, frayed cords,
etc.
If any defect is found, replace the drive belt.
Hint:
cracks on the rib side of a belt are considered acceptable. If the
missing chunks from the ribs are found on the belt, it should be
replaced.
2 ...


