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:
Horn
To sound the horn, press on or close to the
mark.
CAUTION
■Caution while driving
Do not adjust the steering wheel while driving.
Doing so may cause the driver to mishandle the vehicle and cause an accident,
resulting in death or serious injury.
■After adjusting the steering wh ...
Problem symptoms table
The suspected circuits or parts for each problem symptom are shown in the
table below. Use this table to
troubleshoot the problem when a normal code is displayed in the diagnostic
trouble code chart but the problem
is still occurring. Numbers in the table indicate the order in which the
circ ...
Wiring diagram
1 Inspect terminal voltage(pi)
(a) turn
Turn the ignition switch to on.
measure voltage between terminal 5 (pi) of cruise control
ecu assy and body ground, when the cruise control main
switch button is on and off.
Ok:
2 Inspect combination meter assy
3 Check harn ...