|03-24-2013 07:06 PM|
Back from the dead...
**I take zero personal liability for the information contained herein.
**For all inclusive liability issues... I will not pointedly describe certain specifics, but more to the point, instead give you a direction of thought on what *may* need to be considered for one to get this to work.
**I will also advise one to purchase factory 'Workshop and Wiring Diagrams' from HELM Publications (on CD/DVD.)
Now... with that out of the way. Here is the the basic operational logic behind the Electronic Stability Control (ESC) and what happens:
So... what I believe is that one of three interrupts needs to occur:
Notice that I left off any mention of any kind of interrupt to any Wheel Speed Sensor (WSS.) An interrupt to any WSS will hard fault (and set a DTC code) within the ABS... so, since that isn't a direction that we are interested in... faulting any WSS isn't going to be a player in this.
When reading the logic of the individual systems description and their subsequent operation the three listed interruptions will not disable the Anti-lock Braking System (ABS) nor will effect Dynamic Proportioning through the Electronic Brake Distribution (EBD.) However, I also believe that it may in some way influence operations of associated systems... but likely not hard fault an "ABS" trigger (set a DTC code/red fault indication) within the the Instrument Panel Cluster (IPC.)
The idea is to only interrupt as little as possible without effecting other systems, or... inducing an unsafe operation as an effect from deliberate interruption.
At most any of this will likely introduce a soft fault and possibly set codes in the range of "C0061:xx to C0063:xx"... which can be reset with a scan tool upon fault removal and completing "Diagnostic Routine W."
Another though... would be to install the factory "ST" switch into the car. Here is why that might be a player:
The F-150 owners had issues with the locking differential and stability control, very much like the Focus have now... and by replacing the BCM with that of one from its brother, the Raptor... it worked just the same for the non-Raptor F-150's and they gained control of the locking differential and the ability to shut off the ESC.
Like the F-150... the wiring is already there. However, with the Focus... what is unknown or untested is whether or not the programming is there to support it.
An interesting subject to kick around though...
|03-25-2012 03:41 PM|
What about simply a(n electronic / voltage) spike-free simultaneneous cut-off of the (four?) wires leading to / from the angular motion accelerometer, that controls the ESC system along with the steering angle sensor? Surely there would be no need for the ABS logic module to simulaneously kill-off ABS, TCS and ESC, just 'cause one of the two main inputs for ESC has been deactivated? That way, at least ABS could remain active.... Now, I expect that the angular accelerometer (and indeed, most sensors) is CAN BUS.... so it's not like you can exactly modify a resistance, or cut-off a signal, as I understand it.
Come to think of it, though, TCS shutoff is important, too, as between ESC and TCS - the chassis tuning is really impacted.
Thx, in any case. Any others with ideas?
|03-25-2012 01:25 AM|
There should be access to some of that in the tuning software but to what degree I wont know till SCT get working tuning software for the 2012 Focus
|03-24-2012 10:49 PM|
ECU Modification Question
In a certain sense, the following should go into the Wheels, Tires, Brakes, etc. discussion forum -- but I really suspect it's only the ECU / Logic Module modifications fellows who'd know how to answer... So please humour me!
Re the 2012 Focus... with ESC and TCS integral with the car: I want to reduce understeer by adding more rear roll stiffness... but I strongly suspect it'd be counteracted by the ESC. I want to make ESC and TCS switchable-off, for Drivers Ed days, or for quick-action-off, in extremely low traction situations where non-switchable (or not QUICKLY switchable) TCS Off is a safety issue.Many thx for any / all who answer!