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.

Dtc no

Dtc detection condition

Trouble area

P0128 Condition (a), (b) and (c):
  1.  cold start
  2.  after engine is warmed up
  3.  engine coolant temperature is less than 75°c (167°f)
  • Thermostat
  • cooling system
  • engine coolant temperature sensor
  • ecm

Monitor description

The ecm estimates the engine coolant temperature (ect) based on starting

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 enabling conditions

Typical malfunction thresholds

Typical malfunction thresholds

Component operating range

Component operating range

Monitor result (mode 06 data)

Monitor result (mode 06 data)

Refer to page 05–27 for the detailed information on checking monitor status.

Refer to page 05–27 for the detailed information on checking monitor status.

    Share this page:

    Other materials:

    Rear seats
    The seatbacks of the rear seats can be folded down. Folding down the rear seatbacks 1. Move the front seats forward. 2. Stow the rear armrest. (if equipped). 3. Fold the seatback down while pushing the seatback lock release button. Each seatback may be folded separately. WARNING Observe the follo ...

    For safe driving
    For safe driving, adjust the seat and mirror to an appropriate position before driving. Correct driving posture Adjust the angle of the seatback so that you are sitting straight up and so that you do not have to lean forward to steer. Adjust the seat so that you can depress the pedals fully ...

    Switches
    Instrument panel light control dial Automatic High Beam switch Heated steering wheel switch* Windshield wiper de-icer switch* Outside rear view mirror switch Door lock switches Power window switches Window lock switch *: If equipped Meter control switches Paddle shift switches*1 C ...