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:

    Circuit description
    The p/t squib (rh) circuit consists of the airbag sensor assy center and seat belt pretensioner (rh). It causes the srs to deploy when the srs deployment conditions are satisfied. Dtc b0130/63 is recorded when a short is detected in the p/t squib (rh) circuit. Wiring diagram ...

    Rear seats
    ► Type A 1 Up Pull the head restraints up. 2 Down Push the head restraint down while pressing the lock release button. ► Type B 1 Up Pull the head restraints up. 2 Down Push the head restraint down while pressing the lock release button. ■Removing the head restraints ...

    Toyota Safety Sense 3.0 software update
    It is necessary to enter a connected services contract, provided by Toyota, to use these functions. For details, contact your Toyota dealer. WARNING ■For safe use When the Toyota Safety Sense 3.0 software is updated, the operating methods of functions may change. Using this system without knowing ...