
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 circuitUnlocking and locking the doors
Front doors
Grip the driver’s door handle to
unlock the door. Grip the passenger’s
door handle to unlock all the
doors.*
Make sure to touch the sensor on
the back of the handle.
The doors cannot be unlocked for
3 seconds after the doors are
locked.
*: The door unlock settings can be ...
Air mix damper control servo motor circuit (driver
side)
Description
The air mix damper servo sends pulse signals to indicate the damper position
to the air conditioning
amplifier. The air conditioning amplifier activates the motor (normal or
reverse) based on these signals to
move the air mix damper (driver seat) to the appropriate position. T ...
Fuel pressure pulsation damper
Components
Removal
Discharge fuel system pressure (see page
fu-9)
Disconnect cable from negative battery
terminal
Remove no. 1 Engine cover (see page es-410)
Remove air cleaner cap sub-assembly (see
page es-411)
Disconnect fuel main tube (see page fu-10)
Remove fuel pres ...