Coolant gauge pegged with AEM Infinity
 

Just got the car running on the Infinity from SOS. There is an issue with the OEM coolant gauge in the cluster now. Regardless if the car is started, or just sitting with ignition turned on, after about 20-30 seconds, the coolant temp gauge pegs fully hot and never moves. I have a Gauge Art CAN gauge connected to the Infinity, and it displays the proper coolant temp. Also, I'm not getting any hot air out of the vents when trying to use the heater. The coolant gauge and heater worked totally fine on the stock ECU. In the Infinity wizard, I have the 00-05 S2000 coolant temp sensor selected, since the car is a 2005. SOS recommended I test the resistance between pin A1 of the vehicle harness and pin 3 on the Infinity connector, which I will do tomorrow. Can anyone offer more suggestions?

that has nothing to do with the ECU, what other changes did you make at the same time?

Other changes made at the same time: ID1700s, AEM FPR, Walbro 450 with SOS rewire kit, SOS flex fuel sensor/wiring.

Before installing the Infinity and fuel system, I had the car running and idling on the stock ECU and fuel system after installing the turbo kit. I bled the cooling system a bunch of times and the heat was working fine. I will check to make sure the heater valve is actually opening too.

Heater valve might have been stuck closed yesterday. It worked just fine this morning. I'll bleed the cooling system a few more times just to be sure there are no air pockets trapped.

This is a own issue. If you search on AEM forums, or just call them, you'll find an updated calibration chart that will get the gauge working correctly