checked through the FSM and could not locate that black box that is on the back of the ecu. i happend to switch over to a power fc and removed the box. now the car wont start, there are no injector pulses or anything. i would put it but i cant find it anywhere. i am just wondering what the box actually does. any help appreciated.

 

Sounds like a fuel cut eliminater.

 

Fuel cut defender! +1^

 

Thats probably the fan recall. It makes the fans run for a couple minutes after shutdown.

Your starting problem probably lies elsewhere. Did you try putting the stock ECU back in? Why do you think that box is related?

I never heard of a fuel cut defender for the FD, so I am going to have to disagree on that one.

 

It was a recall like Tom stated. Shouldnt effect anything related to the car starting.

Check your wiring, around the ecu. Im betting a wire has been pulled from the connector by accident.

 

Yeah I have one of those too, and I don't have a FCD. Did you check the ECU ground in that area?

 

I say it is the unit to make the fans run after shut off if the temps are reached .Th e fans should run for 10 minutes after shut down . If the triggers are to far away from the trigger wheel the PFC may not work but the stock ECU will .Close the air gap between the trigger and the wheel if nothing works .

 

I remember reading this not along ago with another owner who'd had the same issue. I don't remember it being mentioned already, maybe DaleClark would consider adding it to his FAQs that are stickied in the PFC section?

 

I have that black box on my ECU too. It clips onto the ecu mount bracket and sits behind the ecu. There is a stock mazda connector attached to it. My fans don't run with key off, I have no FCD, and my car is a 5 speed.

 

As mentioned above, it's related to the fans and nothing to do with fuel cut. It's the "Cooling Fan Control Module". Page F-145 and 146 in the FSM. I really doubt it has anything to do with the OP's starting issue, but he'll probably need to find it, or buy another.

 

Well, someone else mentioned that it was a recall item that kept the fans running with the key off. That's why I mentioned it.

 

Yep, that's the cooling fan recall. That box goes to a harness that plugs in between the white connectors going to the ECU harness. It also has a ground wire and a black single wire connector for testing.

If the white connector that the fan recall box is plugged into is unplugged, weird things will result. Don't know if that would mean a no-start, but that's not helping things.

I need to do a writeup on the fan recall junk, and how to properly toss it in the trash .

Dale

 

I forgot to plug that little box in when I put my car back together and the engine wouldnt start. It was driving me nuts until I realized that the little box was sitting under the floor mat and I had an extra plug next to the ECU. I plugged it in and the car started right up.

 

Well, my fans don't run with the key off and I have one... no electrical issues with the car. It's never been hacked...

 

ditto, and I know I had that recall done (though I don't know if the dealer did it correctly). I've always assumed the fans don't run because I let it cool down before shutting it off.