Toyota Corolla (E120): Circuit description
If the engine coolant temperature (ect) does not reach 75°c (167°f) despite sufficient warm – up time has elapsed.
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Dtc no |
Dtc detection condition |
Trouble area |
| P0128 | Condition (a), (b) and (c):
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Monitor description

The ecm estimates the engine coolant temperature (ect) based on starting temperature, engine loads, and engine speeds. The ecm then compares the estimated ect with the actual ect. When the estimated ect reaches 75 c (167 f) the ecm checks the actual ect. If the actual ect is less than 75 c (167 f), the ecm will interpret this as a fault in the thermostat or engine cooling system or thermostat and set a dtc.
Monitor strategy

Typical enabling conditions

Typical malfunction thresholds

Component operating range

Monitor result (mode 06 data)

Refer to page 05–27 for the detailed information on checking monitor status.
Other materials:
Using the key (vehicles
without a smart key system
and with a wireless
remote control function)
Releasing
To release the key, press the button
Folding
To stow the key, press the button
then fold the key.
Using the mechanical key
(vehicles with a smart key
system)
To take out the mechanical key,
slide the release button and take
the key out.
The mechanical key can only be
inserted in o ...
Malfunction in clock
Wiring diagram
Inspection procedure
1 Inspect fuse
Check the continuity in cig fuse.
check the continuity in dome fuse.
2 Inspect harness or connector
Check voltage.
Remove the clock assy with connector still connected.
Measure voltage between ter ...
Check dlc3
The vehicle’s ecm uses the iso 9141–2 for communication
protocol. The terminal arrangement of the dlc3 complies
with sae j1962 and matches the iso 9141–2 format.
Hint:
if the display shows unable to connect to vehicle
when you have connected the cable of the obd ii scan tool or
the h ...


