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:
Circuit description
The actuator motor is operated by signals from the cruise control ecu assy.
Acceleration and deceleration
signals are transmitted by changes in the duty ratio (see below).
Duty ratio:
the duty ratio is the ratio of the period of continuity in one cycle. For
example, if a is the period of co ...
Switches
Instrument panel light control dial
Automatic High Beam switch
Heated steering wheel switch*
Windshield wiper de-icer switch*
Outside rear view mirror switch
Door lock switches
Power window switches
Window lock switch
*: If equipped
Meter control switches
Paddle shift switches*1
C ...
Turn signal lever
Operating instructions
1 Right turn
2 Lane change to the right (move the lever partway and release it)
The right hand signals will flash 3 times.
3 Lane change to the left (move the lever partway and release it)
The left hand signals will flash 3 times.
4 Left turn
■Turn signals can b ...


