What does po128 code mean in english. thanks

PO128 -- engine coolant low or thermostat not working
P0440 - EVAP system malfunction, gas cap loose - Cat convertors missing from car can cause this
P1189 - Engine Oil Pressure Switch Circuit -- CAT CONVERTORS MISSING FROM CAR can cause this.

Oil pressure switch issue
Coolant temperature sensor issue
EVAP system issue
All different issues, so I suggest seeing a mechanic.

PO 128 is a coolant temperature beyond threshold code. It means your thermostat is stuck and needs to be replaced.

change thermostat could be stuck open.

P0128:
P0128 OBD-II Trouble Code
Technical DescriptionCoolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature)

What does that mean?This means that the engine's PCM detected that the engine has not reached the required temperature level within a specified amount of time after starting the engine. The intent of the P0128 code is to indicate a faulty thermostat. Similar codes: P0125

In determining the engine did not reach a "normal" temperature, it takes into account the length of time the vehicle has been running, the intake air temperature (IAT) sensor reading, the engine coolant temperature (ECT) sensor reading, and the speed of the vehicle.

CausesA code P0128 may mean that one or more of the following has happened:

Low engine coolant level .
Leaking or stuck open thermostat .
Faulty cooling fan (running too much) .
Faulty coolant temperature (ECT) sensor.
Faulty intake air temperature (IAT) sensor .Here's a link on replacing your thermostat.

P0128 is an insufficient coolant temp code. Which means the coolant temp is not coming up to full operating temperature fast enough or not at all. The fix for this is to replace the thermostat.

I’m happy to assist further over the phone at https://www.6ya.com/expert/jeremy_d728a59f986299fa

no the code PO128 on the cobalt mean defective thermostat. nothing to do with driving experience

Sounds like the thermostat may be stuck open or has anyone put a colder thermostat in the car,because once it starts to get cold it will throw a SES with a colder then stock thermostat.

Code PO128; coolant temp below thermostat regulating temp. Replace the thermostat and that should address your issue.

Thank you for using fixya and good uck

CHECK TO SEE IF THE THERMOSTAT IS STUCK OPEN(PO128)ALSO CHECK TO SEE IF A WIRE IS BURNED ON THE EGR POSISTION SENSOR,OR IS UNPLUGGED(po403)

replace the thermostat. computer sees engine is running too cool thermostat stuck open.