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:
Cleaning and protecting the vehicle exterior
Perform cleaning in a manner
appropriate to each
component and its material.
Cleaning instructions
Working from top to bottom,
liberally apply water to the
vehicle body, wheel wells and
underside of the vehicle to
remove any dirt and dust.
Wash the vehicle body using
a sponge or soft cloth, ...
Driving mode select switch
The driving modes can be
selected to suit driving condition.
Selecting a drive mode
Operate the driving mode select
switch forward or backward to select
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Normal mode
Provides an optimal balance of fuel
economy, quietness, and dynamic
perf ...
Do-it-yourself service precautions
If you perform maintenance
by yourself, be sure to follow
the correct procedure
as given in these sections.
Maintenance
WARNING
The engine compartment contains
many mechanisms and fluids that
may move suddenly, become hot,
or become electrically energized.
To avoid death or serious injury,
obser ...


