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
1. Inspect defogger relay (marking: def)
Remove the defogger relay from the instrument panel
j/b.
inspect the defogger relay.
Standard:
If the result is not as specified, replace the relay ...
Pressing power switch does not start system
Wiring diagram
Inspection procedure
1 Inspect radio receiver assy(+b, acc, gnd)
Check that the continuity between terminals at each
condition, as shown in the chart.
Standard:
Check that the voltage between terminals at each condition,
as shown in the chart.
Standard:
...
Out side moulding
Replacement
Hint:
use the same procedures for the rh side and lh side.
1. Remove outside moulding
Put protective tape around the moulding.
insert a piano wire between the vehicle body and moulding.
tie objects that can serve as handles (for example, wooden
blocks) to all ...


