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
1 Inspect dlc3 terminal voltage
Turn the ignition switch to on.
measure voltage between terminals 13 (tc) and 4 (cg) of
dlc3.
Ok:
voltage: 10 – 16 v
2 Check harness and connector(between cruise control ecu assy
and dlc3)
Check for open and short circuit in harness ...
General maintenance
Listed below are the general
maintenance items that
should be performed at the
intervals specified in the
"Owner's Warranty Information
Booklet" or "Owner's
Manual Supplement/Scheduled
Maintenance Guide". It
is recommended that any
problem you notice should
be brought to the attention
of your Toyota ...
Canceling and resuming the constant speed control
1 Pulling the lever toward you cancels the constant speed control.
The speed setting is also canceled when the brakes are applied or the clutch
pedal (manual transmission) is depressed.
2 Pushing the lever up resumes the constant speed control.
Resuming is available when the vehicle speed is mo ...


