CEL appeared

[Aliments]

Gidday

My check engine light appeared today. Checked the codes and it was 12 long and 8 short flashes. Code 128.

Assuming i counted the flashes correctly that points to the Coolant Thermostat.

Taking car to mechanic in the morning to have scaned . If this is the case and its the Thermostat that needs replacing what sort of cost all up including labour is a fair price ?

Ta

[driftweez]

Ok dont know the car but thermostats are mechanically operated and dont usually have sensors..things may have changed with newer cars..and I never knew you could get a 3 digit code..again have things changed??

[Guest]

Did you use an obdII scanner to get that code or did you use the wires under the dash?

code p0128 on a scanner is thermostat malfunction

128 on the wires doesn't exist.

[WRXONP]

how does diagnosis know the mechanical thermostat is stuck???

[Guest]

I presume its measures the temp changes in the engine and predicts when the thermostat is supposed to open and checks for the change in the engine temp. When that changes doesn't occur it calls the thermostat error.

Thats how I think it would work but I could be way off.

[WRXONP]

tru i think that would work with extra water temp sensors maybe??

[log1call]

 EVILB4 said:

I presume its measures the temp changes in the engine and predicts when the thermostat is supposed to open and checks for the change in the engine temp. When that changes doesn't occur it calls the thermostat error.

Thats how I think it would work but I could be way off.

What he says..

[Flippymoi]

For the benefit of others searching for the 128 fault code, it is possible to get with the wires, as I just got it myself. However I am not sure if it is a thermostat issue since the car has no problem coming up to temp and doesn't overheat. Perhaps a faulty temp sensor. If anyone else has figured out what the 128 fault code through the wire connector diagnostics means, please post here.

[DK]

Got CEL 128 also, seems to have only come around via the cold weather could be a coincidence though. Anyone else had this? Best just to replace the thermostat reset the code and see if the code comes back?

http://www.obd-codes.com/p0128

[Stodart]

According to my auto mechanic boss, fault codes thrown up are not always whats the exact fault / problem so its a good idea like you suggested and get professional advice.

[Rosssub]

P0128 Coolant Thermostat (Coolant Temperature Below Thermostat Regulating Temperature). Cold weather triggers this, do a reset and see if it comes back. Comes up as 128 through diag wires cause cel light cant flash for 0. Your mechanic is going to charge you a fortune for fitting a new thermostat and scanning for nothing.