Coolant Temp and EPS S2000 Turbo | AEM
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Last seen: 1 year 1 month ago
Joined: 06/19/2019 - 21:30
Coolant Temp and EPS S2000 Turbo

I am extremely new to the idea of an aftermarket ECU, so bear with me here. I'm using an AEM V2 plug and play system

I've installed a turbo into my car with many different upgrades (Can list if needed) and after all of it was installed, I feel I've run into a situation that I haven't expected. All the added parts and gauges work fine, but somehow I've lost proper Voltage from the ECT. Despite the system claiming that everything works with the OEM hardware, I can't get the ECT to read. Voltage remains at .06 and doesn't change more than .01 at random. Its strange and.. I'm at a lose. 


Additionally, though I dunno if that will apply here, my EPS will not communicate with the AEM and won't learn in properly. I've followed the instructions for normal relearn but it just doesn't work with the AEM ECU. Where as when the OEM ecu is installed, the relearn works without an issue. 

Last seen: 2 months 3 weeks ago
Joined: 06/07/2014 - 14:29
That is not an Infinity ECU,

That is not an Infinity ECU, so most of the Infinity-related suggestions in this part of the forum won't help you.  Your ECU is a Series2 EMS , and those had a separate chip on them programmed make the OEM coolant gauge work. That separate chip simply measures the voltage of the coolant temperature pin (pin C26 on the OEM harness) and broadcasts a pulse signal to the OEM cluster using pin A1 on the OEM harness. The first thing to check is the input (C26) with a multimeter. Try disconnecting the coolant temp sensor plug in the engine bay, the voltage should be about 5V with the sensor disconnected. Check that the ECU's software reading Coolant Volts  matches what you see with a multimeter.  If you have access to a stock S2000 of the same model year, it might be quicker to plug the ECU into that and double-check if the coolant measurement works as expected.


I'm not very familiar with the EPS, I think I've heard it will show EPS errors when you first install but then continue working after driving the car a short distance.

Hope that helps,