Diablosport Forums

P0128 Thermostat code fix

Anything new on this? I understand it has been a difficult one to crack but it has been said for 3 releases now that it would likely be in the next one... still none..... so, ummm, maybe the next one then?

Also, a line was dropped in a forum somewhere at some point that we may eventually have some new MDS stuff to play with too? Maybe make it kick in more often, less often, etc... Also might address the heavy kick in and out? Anything ever come of this?

But dont get too off track, my main concern is that P0128 fix!

Yeah, they are still looking into a fix for this.
Do you run a 170* t-stat?

Nope run a 180 in both the wife's 2006 300C SRT8 and My 05 Mag R/T. Both do it constantly... (we live in fairly mild temps and no stop and go traffic... temp runs at a constant 178)

I think I have seen some get away with upping the low speed fan settings to allow the temp to come up quicker, but we'll keep looking into it.

Thanks

Even with Stock fan speeds it still does it. The threshold is at 180, both our thermostats open around 178. With the fact we are doing 70+ MPH right out of the gate, for 30+ minutes, the wind across the radiator doesnt allow it to get one tick above that 178, 179 mark.... Boom, the code. We have no stop time, no sitting in traffic, no accelarating or decelerating, etc....

Even driving around in 4th doesnt work, we have to actually drive in 3rd gear to get it up over that 180 mark...

I am no programmer, and I have no idea how the code really works from their side, but if they could just set it to say 170 as the threshhold. they dont actually have to turn the code completely off, just change the value it is looking for. Since most of us use a 180, even setting it at 175 would be fine. Leave the rest of the coding, timing, checking of outside temps, etc, the same.... Just my 2 cents.

if you want to send in your original backup and your current installed tune.. I can make a change to it to test out the thermostat stuff.

Will have it to you shortly....

Daniel, I got the email and forwarded it to MikeW.

Thanks

You may want to try another tstat. I had this problem too (before diablo). I definately has to do with getting on the highway right away and the amount of time it takes for the temps to warm. But I swapped it out for a different brand 180 stat and haven't had the code since (over a year ago).

Until they make a digital thermostat, this one could end up being hit and miss.

I've been whining about P0128s since last fall.

If the 'Dan' fix works, I'd like to try it as well.

180 degree T'Stat, 93 octane CAI tune.
When the ambient is above ~60 degrees F, no problem.
When the ambient is below ~20 degrees F, no problem.
From about 25-55 degrees, repeated P0128 - I believe it takes three (?) occurrences of below temp operation to trip the fault.
If the system is looking for 180 as a default temp, why not extend the 'time-to-temp' or reset the 'target' to a lower value - like 170?

Hey guys, 2 days in a row, NO CODE! It was 50 degrees out yesterday, and about 48 today. Not sure what the cut off point is for the ambient temp to be before it changes its logic (ie, i never got the code before when it was below freezing outside) but at least in the low 50 range it seems to be working so far.

Unfortunately this one is a hard one to test, so I am not 100% sure it works yet but so far so good!

When you get a minute if you could send me back the one for the wife's car to test out I would appreciate it, she is the one who has been bit*in about it the most...

Sent.

Any news on defeating the thermostat CEL?