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


Leave your comments

Post comment as a guest

0

    Comments
    Subscribe To These Comments-----   

    • No comments yet.

    Latest Articles

    Chevrolet Blazer Lost Power ...

    2000 blazer 4x4 lost power to drivetrain going down the ...

    Dodge Durango Timing Chain ...

    My 03 Dodge Durango 4.7L engine was blowing white smoke ...

    2002 Chevy Blazer Keeps ...

    My 2002 blazer keeps dying on me when I am driving, and ...

    1996 Lumina Dies Looses ...

    1996 Chevy Lumina 3.1 L. I have good fuel pressure,spark ...

    Silverado Won't Start Cold

    My 1992 Silverado 6 cylinder turns over but will not run if ...

    How Things Work

    Power Steering- Electric- How Does It Work

    The electric power steering (EPS) system reduces the amount of effort needed to steer the vehicle. The system uses the body control module (BCM), power steering control module (PSCM), torque sensor, discrete battery voltage supply circuit, EPS motor, serial data bus, and the instrument panel cluster (IPC) message center to perform the system functions.

    Read more...

    Common Engine Codes

    Oxygen Sensor Code P0130 - P0141

    The powertrain control module (PCM) supplies a bias voltage of about 450 mV between the heated oxygen sensor (HO2S) high signal circuit and the HO2S low reference circuit. When measured with a 10 mega ohm digital voltmeter, this may display as low as 350 mV. The oxygen sensor signal varies from about 800 mV when the exhaust is rich, to about 50 mV when the exhaust is lean.

    Read more...