Tuning the Cooling System

I've done a little bit of modification to my cooling system and am trying to figure out how to tune my fans for the best performance settings.

All I've done is replaced the stock 195* thermostat with a 160* and spliced in SLP'S Manual Fan Control Switch (which works perfectly btw). To make sure my 160* stat was actually opening at 160* I opened the bleeder so check if coolant came out steadily (meaning the stat was open), sure enough it opens right at 160* and works great too. But there was one small problem, the SES light came on and after scanning I found out it was

P0128 Coolant Thermostat

After the SES light came on my temperature gauge dropped down to zero and ceased function all together. Also, both my fans immediately came on I guess as some kinda fail safe to keep the car from overheating. But the stat never stopped working, and coolant flowed as normal! Once I cleared the SES light everything went back to normal and the temp gauge worked again... Should I disable P0128?

Also, my fans are set to come on at 181 and go off at 174 (stage 1) and 190/185 (stage 2) is that a good setting?

I had the same issue with that code and I deleted it. As far as the fan temps, what I did was to figure out the relationship of stock settings to stock thermo and keep that same ratio. I don't know what I have off hand but I know I have fan 1 set at 181on 176off.

The problem is our cars do not like 160*. The PCM thinks it is too cool, sets the code, and drops off the indicated temperature. I spoke with the people at Hypertech and they confirmed this. I went to a 180* and it works great.

This all happened before HP Tuners so I never tried to delete the code and do not know if deleteing the code will keep the temp gauge working or not. ANother option is to put a resistor inline (search Firebirdv6.com). with the temp sensor but this will effect other things. Hope this helps.

post your OS number or email me your bin. I'm sure we can mod the test for this in future.

After I dropped the Coolant Thermastat code, the temp gauge never went out again.

Well, I just need to put the 160* back in, delete a code, and I should be fine. Thanks.

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Originally Posted by Chris@HPTuners

post your OS number or email me your bin. I'm sure we can mod the test for this in future.

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fwiw i had this code in my gtp as well not sure if anyone sent you your bin but i sent in my file to support a few days ago if you need it for this as well.

Thanks
Bill