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
Shifting from 1st to o/d is performed in combination with on and off of the
shift solenoid valve s1 and s2
controlled by ecm. If an open or short circuit occurs in either of the solenoid
valves, the ecm controls the
remaining normal solenoid valve to allow the vehicle to be operated smoothly
...
Circuit description
The p/t squib (lh) circuit consists of the airbag sensor assy center and seat
belt pretensioner (lh).
It causes the srs to deploy when the srs deployment conditions are satisfied.
Dtc b0135/73 is recorded when a short is detected in the p/t squib (lh) circuit.
Wiring diagram
...
Display and menu icons
■ Display
Content display area
By selecting menu icons on the
multi-information display, a variety
of driving-related information can
be displayed. The multi-information
display can also be used to change
display settings and other vehicle
settings.
Warning or advice pop-up displays
are also ...


