Power FC Communication Error

[Matman03]

Ok this is a pretty long going problem and I have hit a wall.

Short Story:
Wiring Specialties Harness - Hacked to hell from install of SAFCII (POS)
SAFC Removed and Harness Repaired (Soldered and Heatshrink)
Installed Power FC
Clicking Noise from Relays near driver feet
Power FC Reads ** Communication Error **
Voltages checked for ECU Power and Backup Power - 10v
(range for PFC is 7-14v)
ECCS Relay checked and working
All Connections in Harness checked
Stock ECU still starts car and can run for short period but crappy.

I am not sure where to go from here, I have hit a wall. You guys are the experts.

Engine Information - SR20DET Redtop - PFC Confirmed Correct Model
Running Z32MAF

Let me know if you need more information, and your help is greatly appreciated!

[Matman03]

Anyone?

Is the Pin out on the Power FC different than the 62 ecu? or possibly wiring specialties did their harness differently?

[Kingtal0n]

If the harness is hacked to [email protected]()*@# you should just get a fresh one. They are so cheap now because nobody keeps them anymore... or uses them... since they buy that wiring specialties [email protected]*(* Which I have also had problems with.

One car with a wiring specialties harness has a pin at the ECU that does not make contact with the ECU. I had to stick little bits of wiring into the harness connector to make the ignition work right on that cylinder. Who knows what other pins do not make contact- the only reason I found that one was because it was on the ignition coil pack. We would jiggle the harness and the cylinder would randomly start to fire again.

Ill never buy or recommend wiring specialties. OEM ftw.

[Matman03]

Thanks kingtal, so could I use a stock harness for the s13 redtop in s14 body? Also since the stock ecu runs on the current wiring harness....could that still be the issue?

[Kingtal0n]

When you say power fc says, you mean the commander?

Did it ever used to work? Sometimes you have the wrong commander for the power FC and it does something like that.

If the factory computer works, and the PFC does not, then either the ECCS wiring is messed up or the PFC is messed up, or the wrong commander is being used... there are lots of IF's..

The harness follows the engine, but needs to be re-wired for the chassis. Any harness can work with any chassis if you re-wire it for that chassis. But many people wish to skip this step and take the easy way out and buy a pre-made harness. But those are not OEM, and the quality control is nothing even close to OEM from what I have seen.

[Matman03]

The power fc is brand new and has also been tested by apexi for functionality.

The eccs has been tested for voltage and function

So could there be a way to test the root of the problem?

[Mikester]

So you already switched the MAFS to VG30 under your settings? It could be that simple.

[Mikester]

On the Commander, you can also reset everything and try that, re-select VG30 MAFS and start it up.

[Matman03]

The commander will not let me enter anything it boots up showing apexi logo then model and version number then **communication error** on the commander. Clicking relays on driver side of car at key on position. Hope that helps explain issue. Car is running z32 MAF

[Mikester]

IIRC, the PFC is sensitive to not only the power input, but also the 'backup power' input... or something to that effect. Had a buddy with a similar issue... Recommend a known-good ECU harness that hasn't been hacked to smithereens. Even if it does not fix the issue, it gives you a much better chance of finding gremlins.

[Matman03]

Which harness would you suggest then?

[Mikester]

^^A non-hacked to hell WS harness :_)

[Matman03]

They have a repair service for $80 should I send it back to them?

[exhaust_note]

My s14 is doing the exact same thing with a wiring specialities harness. Stock 62 ecu everything works fine. Power FC all the relays keep cycling super fast and the commander either says error or flips back and fourth from apexi screen to sr20det screen.

Stock ecu plugged in I have 11v at ecu power pin. Only 8v with the Power FC plugged in.

[Matman03]

Wow, what a resurrection! Old Thread. Did you check the ECCS relay? Also make sure you have the correct voltage I do not think 8v is enough. My issue actually ended up being a damaged wiring harness, I sent it back to wiring specialties and they were very helpful. I ended up with a new harness and then the clicking relay noise went away. Car started up at least. LOL Hope this helps.

[exhaust_note]

8v isn't enough. But it's only low when the power Fc is plugged in. If I plug the stock ecu in it is battery voltage.