po128

[01outlaw]

i just went for a cold ride and the ses came on so i go up to advanced and they pull the code of P0128 WHAT DO YOU THINK?

Thanks Josh

[alian]

P0128 = ECT below thermostate regulating temp. does this help???
Cheers Ian

[Cutlass]

Usually means the T-stat is bad/stuck open. Or someone installed a low temp t-stat

[alian]

Usually means the T-stat is bad/stuck open. Or someone installed a low temp t-stat

I am about to fit a 160 Tstat to mine in the coming week so will be interesting to see if it comes up.
Ian

[Cutlass]

I am about to fit a 160 Tstat to mine in the coming week so will be interesting to see if it comes up.
Ian

Most people seem to get away with it. 160 Tstats usually run around 170 in these engine and I think the code sets for temps below 160.

OP, here's some more info on P0128 from the service manual

DTC P0128 is designed to detect a skewed ECT sensor or a faulty thermostat.

Excessive coolant flow through the bypass hose to the throttle body may cause this DTC to set.

A skewed ECT sensor can cause a DTC P0128 to set.

A skewed IAT sensor can cause this DTC to set. The IAT sensor should read near the ambient temperature, with the engine running.

[01outlaw]

Usually means the T-stat is bad/stuck open. Or someone installed a low temp t-stat

I dont think it has a 160 in because it runs right at 210 in the summer

do you think the ses light will reset its self?

[Too Fast]

It will, after many many restarts/correct warmups after you fix the problem. 49 times out of 50 this is code is from a cold running engine from a defective thermostat. Is your heat output not very hot? This would confirm your bad t-stat, assuming your coolant is full, along with this code, and a temp gauge staying low.

[01outlaw]

It will, after many many restarts/correct warmups after you fix the problem. 49 times out of 50 this is code is from a cold running engine from a defective thermostat. Is your heat output not very hot? This would confirm your bad t-stat, assuming your coolant is full, along with this code, and a temp gauge staying low.

not very hot it also smells like anti-freeze? and yes the gauge was low it takes a long time to warm up

[Too Fast]

^^^well there you go. t-stat for sure, but make sure you have no coolant leak since you smell something. You could just be really alert for any other smells. I know there is a place on my drive to work where I swear I smell coolant, and always check my gauge!

[01outlaw]

ses light went out after a proper warm up thanks for all the help

[Too Fast]

Some codes take lots of drive cycles, others not so much. I've found most PCM strategies are different.