I‘m in the process of gutting and caging out a 2006 BF Falcon SR for a racing. The association category it will race in requires the interior to be gutted, my intention is to leave only the upper skin of the dash to keep it pretty, everything under it / in it will be either removed or reduced, the complete ICC is to go, only the cluster will remain, wiring will be reduced down to only that necessary to keep the car going.

Recently I attempted to remove the ICC, I got it loose enough to separate it from the loom plug, and attempted to run the car. The result was not what I expected, cluster stopped working, some beeping / warning sounds by memory, engine would not rev any higher than 2500 – 3000rpm, various lights on etc. I then ignition’d off, pushed the ICC back in reseating it on the connector, started the car again, and everything worked again (well except ABS / ESP lights, I’d previously pulled the ABS fuse)

My take on this is that separating the ICC connection killed the CAN Bus network, cutting the communication between PCM & Cluster, triggering the PCM to cap engine revs, no PCM signals getting to cluster (hence no tacho, warning lights ect)

From my own research, I was under the impression the CAN bus twisted pair network on the car runs end to end between the PCM & Cluster, and that the ICC tee’s off this twisted pair, along with any other unit using the CAN bus, so I’m stumped that CAN bus communication is lost by popping the ICC out.

Anybody have any ideas on how to get around this, I haven’t been able to find any pointers here or anywhere else (google), only folks upgrading ICC’s, but then I guess turfing an ICC is not exactly common

Not being all too knowledgeable on the subject I do however remember from my readings that the ICC is integral to the operation of the entire system, the bus is made up of the various systems and requires feedback from all to operate correctly, not somewhat standalone like previous systems.

Would an aftermarket computer be allowed in the category? Might be the easiest option. Also there have been a few people running twin cams off the OBD1.5 AU system could that be another viable option?

That's because the bcm is attached to the bottom of the icc. If you can separate that from the stereo and have only that plugged in, it may work.

as already stated, the bcm is under the icc unit. from my understanding, when you turn the key, the bcm, via smartlock (or whatever its called now) asks various bits of the car for thier info. the bcm will be sent various codes by certain bits and so many of them have to match up with the info in the bcm for it to allow the car to start.

Had another play with car last night

To clarify, only the plug in the back of the ICC was separated, not those on the bottom of the ICC that I understand relate to the BEM. Pretty clear now I will have to keep the BEM unit to avoid having to flash the PCM to remove security, will look to relocate the BEM when I turf the ICC assembly

I believe the one being separated in the back relates to the ACM (Audio Climate Moduel??) inclusive of ICC screen judging by the fact that’s where the wires appear to go to.
I have resolved the rev limit issue, I had been giving it a boot full in neutral, revs right out in park no worries

The noise / alarm sound was due to a very sick reverse parking system, now sorted.
The tacho still drops out when I separate the ICC back connection, I ended up interrogating the ford wiring diagrams, and think I have a handle on it now. The info I previously had indicated the CAN runs directly from PCM to Cluster, and suggested various units tee off it, but this is not the case. The wiring actually goes PCM – ABS – HIM – BEM – ACM – Cluster, at each intermediate unit the twisted CAN bus pair goes into the unit, and out separately, so unplugging the ACM / HVAC in effect breaks the signal path to the cluster and ACM only, as they are at the nd of the line so to speak

This sort of explains why the car still started with ACM connection separated, BEM still had a signal path to the PCM, though I was previously of the understanding that if the cluster CAN connection is broken, the CAN will not work, something to this effect is even stated in the ford manual.

I’m not sure if each intermediate unit (ABS / HIM / BEM) does anything to the CAN signal as it passes in and out. Down the track I’m going the bridge the CAN in and out pairs at the ACM plug to see if that resolves the Tacho issue, which will confirm either way. If that works the cluster should also then still report any engine faults.

I’m also going to attempt to remove the ABS / DSC from the CAN circuit, by mimicking the wiring arrangement in the ford manual for non ABS / DSC falcons, hopefully that will drop out the warning lights that illuminate since I cut the ABS power.

If its for racing and you are allowed to modify the ecu programming you can get people who can remove the pats security allowing the ecu to run standalone.

if you bridge the can bus wires it will work. Inside each module is a can bus bridge as well - thats why on the wiring diagrams it appears as though the wiring splices into it

Thanks blokes, I appreciate your comments

Yeah no limits on flashing the ECU in the class it's destined for, I'm just trying to avoid flashing it, as i really want to see just how far you can go before going down that path.

I'll add posts down the track as it progresses

you may be able to get someone just to remove the PATS functions without modifying the rest of the calibration if you want to stay standard

can anyone tell me if this is the same story for AU3?
i have aan AU ECU only in an XH with the XH wiring loom modified.
the OBD will not work, so i'm assuming it needs contact with the BCM, but may be wrong.