
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
![]()

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 circuitSmart key system
The following operations
can be performed simply by
carrying the electronic key
on your person, for example
in your pocket. The driver
should always carry the
electronic key.
Locks and unlocks the side
doors
Locks and unlocks the back
door
Starts the engine
â– Antenna location
Antennas ou ...
Inspection
Inspect generator brush holder assembly
Using a vernier caliper, measure the brush length.
Standard length:
9.5 To 11.5 Mm (0.374 To 0.453 In.)
Minimum length:
4.5 Mm (0.177 In.)
If the brush length is less than the minimum, replace
the generator brush holder assembly.
Inspe ...
Compressor and pulley (for 2az-fe)
Components
Removal
Discharge refrigerant from
refrigeration system (see page ac-172)
Disconnect cable from negative battery
terminal
Caution:
Wait at least 90 seconds after disconnecting the
cable from the negative (-) battery terminal to
prevent airbag and seat belt pretensione ...