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:
Inspection procedure
Hint:
read freeze frame data using the hand-held tester or the obd ii scan tool.
Freeze frame data records the
engine conditions when a malfunction is detected. When troubleshooting, it is
useful for determining whether
the vehicle was running or stopped, the engine was warmed up or not, the ...
The ambient temperature does not display
Wiring diagram
Inspection procedure
1 Inspect outer ambient temperature sensor
Remove cooler (ambient temp. Sensor) thermistor.
measure resistance between terminals 1 and 2 of cooler
(ambient temp. Sensor) thermistor connector at each temperature.
Resistance:
at 0 c (0 f) ...
Overhaul
1. Remove speedometer drive (mtm) gear
Remove the speedometer drive (mtm) gear from the front
differential case.
2. Remove front differential ring gear
Place matchmarks on the front differential ring gear and
front differential case.
Remove the 8 bolts. Using a hamme ...


