An engine coolant temperature (ECT) sensor monitors the temperature of the coolant. This input is used by the powertrain control module (PCM) for engine control and as an enabling criteria for some diagnostics.


The air flow coming into the engine is accumulated and used to determine if the engine has been driven within conditions that would allow the engine coolant to heat up normally to the thermostat regulating temperature. If the coolant temperature does not increase normally, or does not reach the regulating temperature of the thermostat, the diagnostics that use ECT as enabling criteria may not run when expected.


This DTC will only run once per ignition cycle within the enabling condition. If the PCM detects the calibrated amount of air flow and engine run time have been met, and the ECT has not met the minimum thermostat regulating temperature, DTC P0128 sets.


The most common cause for this is just a faulty thermostat. Or, low coolant level.


More Auto Repair Help


Be Social With Us !

Leave your comments

Post comment as a guest

0
    • No comments yet.

    Latest Articles

    Ignition Switch Replaced but ...

    Question: Will not crank. Changed ignition switch. Still no crank all fuses are good. Do not know ...

    Electronic Throttle Actuator ...

    P0506 - P0507The Electronic Throttle Control (ETC) System uses various inputs from the powertrain ...

    Repeat Blower Motor and ...

    My 1998 Chevy Malibu blower motor keeps going bad.  I have had it replaced three time in the last 2 ...

    2007 Pontiac G6 Coolant Leak ...

    Question: Low coolant level warning problem with my 2007 Pontiac G6 3.5L V6. I Added antifreeze ...

    How Things Work

    Brakes- Front Disc- How Do They Work

    The disc brake system consists of the following components:

    Disc Brake Pads: Applies mechanical output force from the hydraulic brake calipers to friction surfaces of brake rotors.

    Disc Brake Rotors: Uses mechanical output force applied to friction surfaces from the disc brake pads to slow speed of tire and wheel assembly rotation.

    Read more...

    Common Engine Codes

    P0108 MAP Sensor Description and Repair

    The manifold absolute pressure (MAP) sensor responds to pressure changes in the intake manifold. The pressure changes occur based on the engine load. The MAP sensor has the following circuits:

    Read more...