• You're one step from joining Chevrolet Malibu Forum – Tuning, Tech Support & Custom Upgrades.
    Create a free account to post, follow threads, and never miss an update.  Sign up free →

i keep getting this P0128 code

chevyyouth

New member
Joined
Mar 20, 2025
Messages
3
Pls help. This is driving me crazy! i have already replaced the thermostat but the code is still showing. What else could be the issue??
 
if the thermostat is replaced and the code stil appears then you might wanna check out the ect sensor and while your at it you can take a look at the coolant level. its something with the colling system for sure so its just a mater of finding out what it is
 
if the thermostat is replaced and the code stil appears then you might wanna check out the ect sensor and while your at it you can take a look at the coolant level. its something with the colling system for sure so its just a mater of finding out what it is
To add to this, you can also check the wiring or if the radiator fan is stuck on! Agree with @watchbearer11 + you need to bleed the cooling system.
 
Pls help. This is driving me crazy! i have already replaced the thermostat but the code is still showing. What else could be the issue??
If you swapped the thermostat and still get P0128, check the coolant temp sensor next, cos sometimes it sends wrong readings, also make sure your coolant isn't low and the sensor wiring's not messed up. Could just be a faulty signal, not the actual temp.
 
Pls help. This is driving me crazy! i have already replaced the thermostat but the code is still showing. What else could be the issue??
people here got good advice!! but if nothing's solved it yet, it could be a pcm thing but it's not so common, and you'd need a good scan tool.
 
Did you reset the readings already? Assuming you tried everything and it worked but it still shows up, you could maybe clear the code already if it's fixed. Maybe there's just a slight delay in that.
 
Pls help. This is driving me crazy! i have already replaced the thermostat but the code is still showing. What else could be the issue??
that's sucks, I know bcs I had a similar issue last month! It could be bcs of a few things. Could be a wiring issue, a bad sensor, or maybe the computer (ECU/PCM) itself is acting up. depends on code you're seeing.
 
Back
Top