
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 circuitDisplay settings
Settings are available for adjusting the contrast and brightness
of the screen.
Screen for display settings
Press the “setup” button.
Select “display” on the “setup” screen.
Adjust the screen display
Adjust the camera display*
Changes to day mode.
*: If equipped
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Ecu power source circuit
Description
This is the power source for the tire pressure warning ecu.
Wiring diagram
Inspection procedure
Notice:
It is necessary to register an id code after replacing the tire pressure
monitor valve and/or the tire
pressure warning ecu (see page tw-9).
Inspect fuse (ecu-ig1)
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Adjustment procedure
To select a mirror to adjust,
press the switch.
Left
Right
To adjust the mirror, press the
switch.
Up
Right
Down
Left
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