Hey guys
I Have a 2001 rx7 with z006 PFCIt works perfectly fine, except after long drives and shutting the car off and return back after 20 min the commander will say communication error,the car won't start but starter works , the only solution I found was to lit the car sit for 6 hours then the PFC works fine and starts ,
When going for short rides I can turn it off and on with no issues

But long rides, the car will show that message

I once able to start the car with communication error message by starting it in first gear without clutch then pressing and dumping the clutch while it rolled , other than that either flood the engine or wait 6 hours


I wrote to Apexi USA, Apexi Japan without reply for a month

 

I know its dangerous to just throw guesses out there, but the symptoms sound to me like a failing solder joint. Those can cause intermittent issues, often with temperature. Perhaps the ECU is heating up after its been powered up for a while on those long drives and takes some time to cool off. But without taking it apart and thoroughly inspecting the inside there's little to go on other than you know it gets power but doesn't communicate with the commander or start the car.

If you can't find any real factory support (I'm not sure if Apex'i would support electronic products this old, but I don't know) What I'd do if I was in your shoes is take the thing out, and see if there's someone like a local electronics expert or even hobbyist that can take it apart, give it a quick inspection and see if there's anything obviously fishy about it. If they can attempt a pre-emptive solder reflow around the main CPU itself or its supporting chips, that'd be a good non-destructive and relatively cheap troubleshoot.

 

Do you have a stock ECU you can swap in for troubleshooting?

The "communication error" is typically a problem with the commander, usually one of the wires going into the commander has a bad solder joint. This will keep the Commander from working but the PFC typically is fine.

This is a pretty out of the ordinary problem on a PFC, they are generally very hardy.

The curious this is that you basically push started the car one time that happened. That's making me think more of an external problem to the ECU, like a dripping injector, bad compression, or something where it's having problems with a hot start. Or you have a weak starter or battery that's cranking the engine too slow. The two problems may not be related.

Dale

 

Dale replying , awesome, thanks dude

If the commander isn't connected to the PFC ECU, would the PFC ECU function normally? Or it must be connected to a commander to function?

My issue is mainly with the communication error message, I found out also the following
-When the car reaches high temp around 105c 220-230f usually it faces the communication error and not starting
-When the communication error message is present, the fans won't turn on even if I turn ec or EL from defroster-when the car cools down the PFC comes back to normal and fans work with ac or EL defroster-my PFC is brand new, bought it 7 months ago, installed it my self and very carful


Regarding the jump start push , im sure it started because the car cooled down and happens when I was trywas, because when the message of communication error comes the car would stall and turn of when stopped (happened once yesterday)


After you guys commented , I will take the PFC ECU to an electronic expert to check for solder joints issues , I will also take out my CPU No2 , because it freaks out intermittently and functions back normal randomly

 

Thank you

I will go to and electronic expert to check them, I'll update once finished