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:
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 ...
Instrument panel
Engine switch
Starting the engine/changing the positions*1
Starting the engine/changing the modes*2
Emergency stop of the engine
When the engine will not start
Warning messages
Shift lever
Changing the shift position
Precautions for towing
When the shift lever does not move
Meters
Read ...
Inspection procedure
1 Input signal check
See input signal check on page 05–745.
check indicator light operation when driving with vehicle
speed above 40 km/h (25 mph), and with vehicle speed
below 40 km/h (25 mph).
Ok:
vehicle speed above 40 km/h (25 mph):
indicator light blinks
vehicle speed be ...


