
Hint:
This dtc relates to the thermostat.
Description
This dtc is set when the engine coolant temperature (ect) does not reach 75°c (167°f) despite sufficient engine warm-up time having elapsed.

Monitor description

The ecm estimates the ect based on the starting temperature, engine loads, and engine speeds. The ecm then compares the estimated temperature 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 interprets this as a malfunction in the thermostat or the engine cooling system and sets the dtc.
Monitor strategy
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Typical enabling conditions

Typical malfunction thresholds

Inspection procedure
Hint:
Read freeze frame data using the intelligent tester. Freeze frame data records the engine condition when malfunctions are detected. When troubleshooting, freeze frame data can help determine if the vehicle was moving or stationary, if the engine was warmed up or not, if the air-fuel ratio was lean or rich, and other data from the time the malfunction occurred.

Hint:
If any dtcs other than p0128 are output, troubleshoot those dtcs first.


Standard value: 80 to 84°c (176 to 183°f)
Hint:
In addition to the above check, confirm that the valve is completely closed when the temperature is below the standard.

Insufficient coolant temperature for closed loop fuel control
Oxygen sensor circuitDisposal
Hint:
When scrapping a vehicle equipped with an srs or disposing
of the steering pad, be sure to deploy the airbag first in
accordance with the procedure described below. If any
abnormality occurs with the airbag deployment, contact the
service dept. Of toyota motor sales, u.S.A., Inc.
Caution ...
Rear no. 1 Seat assembly (for lh side)
Components
...
If the electronic key does
not operate properly
(vehicles with a
smart key system)
If communication between the electronic key and vehicle is
interrupted („_p. 107) Or the electronic key cannot be used
because the battery is depleted, the smart key system and wireless
remote control cannot be used. In such cases, the doors
can be opened and the engine can be started by follo ...