Nistune Forums

Hey! So i'm having issues hooking up to my ecu. I've looked through the section on diagnosing consult issues but none of it helped. My consult port is hooked up directly to the back on the ecu, has its own separate ground, and is getting battery voltage with key on. Is there any other place in my harness that could be causing this to happen? I thought maybe my ecu was fried but i sent it back to buddy who installed it and he hooked up to it no problem so i'm confused.

I know my ecu could be in limp mode, but there is no CEL or light on in the ecu. Car runs rough right now and i want to monitor some gauges to help me understand whats going on, plus want to tune this damn thing. If anyone could point me in the right direction, or if you need more info let me know.

Car is an s14 zenki with an s15 sr20 swap.
Intake plenum
380lph fuel pump
adjustable fpr
fmic
intake
3" downpipe and elbow
have a turbosmart veeport bov on there but its disconnected right now, and have there 50/50 recirc going on soon.

Ive tried my plms cable on a my buddys stagea and it hooked up no problem! so im confused as to why mines not hooking up.. Also ive tried 3 different mafs, maf wiring is correct. New knock sensor. Im so lost

Just replied via email (same questions) but just to confirm

1. S15 ECU does not have a LED inside it
2. Your check engine light (wired to S15 ECU) should be on when you put the key into 'IGN' position
3. If the ECU is limp mode, the CEL will stay on when engine running (also fans operate)
4. If ECU is not limp, CEL will turn off when engine running

With connection.... before installing Nistune board check your cable works on the vehicle (it will help during times like now where you are not sure if the wiring or the nistune board fitting is a problem)

Considering the ECU was checked elsewhere, looks like wiring issue to the ECU. Make sure the TX, RX lines are directly connected from the ECU to the consult port you added. Dont tap in. I believe the CLK line is not used on S15 so you can leave that disconnected (cut from loom)