View Full Version : The "FI ECU" underhood fuse - whats it do?


greg-ster
06-08-2006, 03:33 PM
I was wondering: does the "FI ECU" fuse in the underhood fusebox kill power to the PCM?

I'd like to re-do my idle learn procedure since getting my o2 sensor replaced, and wanted to make sure that i'd be pulling the right one...

Thanks :thmsup:

greg-ster
06-10-2006, 01:25 PM
anyone?

I'll dance around on a table for your viewing pleasure :banana:

BenjiBoy650
06-10-2006, 01:34 PM
I'm not 100% sure...but you could probably try this out. If you unplug the pre-cat O2 sensor then start the car, you should pop a CEL. Then if you take out that fuse for long enough, the CEL should reset since the ECU lost power. If it doesn't, it might be a separate fuel control module.

I've done this on mine...I pulled the clock fuse and for some reason it's connected to the ECU, so my CEL turned off :dunno:

Anyone know if the 7th gen will turn off the CEL by de-powering the ECU for a few minutes? Mine only took 2-3 mins.

Then again with your previous ECU problems I don't know if you want to be messing with tripping CEL's

princess
06-10-2006, 03:31 PM
I'm sorry. I saw this & then forgot to ask. Things have been crazy! I'll try to remember in the next few days.

greg-ster
06-10-2006, 05:48 PM
Cool beans, thanks princess!

@Benji

My MIL's been on long enough recently...its tired and needs a nap :lmao:

princess
06-11-2006, 09:38 PM
The '05 has an internal memory chip in the ECU & none of the fuses will clear it now. You can do it with a generic OBD2 scanner or you'll need to take it to the dreaded dealer. Sorry. :dunno:

If you get a generic scanner, then you may have to make a code by unplugging something like the TW sensor to make one to clear.

page 7 of this service news has some instructions on using a generic one.

greg-ster
06-12-2006, 08:37 PM
Yikes, looks like a bit of work....thanks princess! :notworthy

I do remember reading in an older (like '04) version of service news that you can do something along the lines of disconnect the battery and touch the positive & negative cables together for like 15 seconds to reset the PCM. Then let the car idle for about 10 minutes without load to idle learn. Is that still valid with an '05?

Something from my Bobistheoilguy sense makes me weary of starting the car cold and holding it at 3,000 RPM like the official idle learn instructions here instruct. I'm paranoid, i know... :paranoid: