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:
Basic repair hint
(A) hints on operations
1
Looks
Always wear a clean uniform.
Hat and safety shoes must be worn.
2
Vehicle protection
Set a grill cover, fender cover, seat cover and floor mat before
starting the operation.
3
Safe ...
Skid control sensor
Replacement
Hint:
replace the rh side by the same procedure as the lh side.
1. Remove rear wheel
2. Remove rear brake drum sub–assy
3. Disconnect skid control sensor wire
Disconnect the skid control sensor wire connector from
the skid control sensor.
4. Remove rear axle hub & ...
Seat belt warning lamp for front passenger’s seat
does not flash
Wiring diagram
Inspection procedure
1 Inspect combination meter assy
Ground terminal c9–11 on the combination meter side.
check that the warning lightlights up.
Ok: warning light lights up.
2 Inspect passenger seat belt warning lamp assy
Ground terminal c9– ...


