What causes a P0128?
The most common cause for P0128 is the engine coolant thermostat is stuck open. When the thermostat does open, the hot coolant should start to flow and quickly warm up the radiator hose. If the radiator hose heats up slowly, the thermostat is stuck open or opening prematurely and needs to be replaced.
Is a stuck open thermostat bad?
Symptoms of a bad thermostat A stuck-open thermostat can also cause lack of heat from the heating system. The Check Engine light may come on too. Besides these two cases, the thermostat may also need to be replaced if the thermostat housing is leaking coolant.
What does p0128 stand for on a car?
Code P0128 stands for Engine Coolant Temperature Below Thermostat Regulating Temperature. The code is set when the engine control module (ECM) determines that coolant temperature is lower than desired or does not increase quickly enough. The engine must reach operating temperature promptly so that the vehicle can enter “closed-loop” mode.
Can a thermostat not fix a p0128 code?
If you ask any mechanic about a P0128 code, most certainly at least 9 out of 10 of them will tell you the thermostat is at fault. The vast majority of the time, they would be right. However, every once in a while it is possible that the thermostat will not fix this code. How serious is the P0128 code? P0128 is not a very serious code.
How to troubleshoot a p0128 OBD-II trouble code?
However here are some suggestions on troubleshooting and repairing a P0128 OBD-II code: Verify coolant strength & level. Verify proper cooling fan operation (check if it’s running more than it should). Replace if necessary. Verify proper engine coolant temperature (ECT) sensor operation, replace if necessary.
When does the PCM record code p0128?
The PCM will record if either of these two criteria is not met. If either fault is recorded again on the next engine startup, code P0128 is triggered. What Are The Symptoms Of P0128? What Is The Cause Of Code P0128? How Serious Is Code P0128? – Low
What could cause the code p0128?
A stuck thermostat is the most common cause of a P0128 code. When the engine warms up, wax inside the thermostat expands pushing down on spring loaded valve. This causes the valve to open; flow to the bypass port is blocked and flow to the radiator is enabled.
What is check engine code p0128?
Check Engine code P0128. The Check Engine light is on with the code P0128 for the coolant thermostat (coolant temperature below thermostat regulating temperature).
What causes a p0128 code on GM?
P0128 Causes: GMC Envoy. Fixing P0128 is usually a pretty easy thing to do, since 90% of the time it’s going to be the thermostat that is throwing the code. Here are the most common causes of P0128: Thermostat Stuck Open- Far and away, the most typical cause for the P0128 code is going to be a thermostat that is stuck open. When a thermostat is stuck open, it allows coolant to flow through the engine at all times.
What is p0128 code on GMC?
P0128 is a relatively common OBDII trouble code. It is triggered when your GMC Envoy ‘s coolant temperature fails to reach the proper operating temperature. It’s a generic powertrain code, which means that regardless of who manufactured the vehicle, it’ll have the same meaning (1996+).