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
If the engine coolant temperature (ect) does not reach 75°c (167°f) despite
sufficient warm – up time has
elapsed.
Dtc no
Dtc detection condition
Trouble area
P0128
Condition (a), (b) and (c):
cold start
after engine is warmed up
& ...
Entire combination meter does not operate
Wiring diagram
Inspection procedere
1 Check fuse
Check that continuity exists of dome fuse.
check that continuity exists of gauge fuse.
check that continuity exists of am1 fuse.
2 Inspect combination meter assy
Check continuity.
Disconnect the ” ...
Other functions
■ Switching between outside air and recirculated air modes
Press .
The mode switches between outside air mode (indicator off) and recirculated air
mode (indicator on) each time is pressed.
■ Defogging the windshield
Defoggers are used to defog the windshield and front side w ...