03-24-2012, 09:49 PM
Join Date: Jun 2011
Location: Vancouver, BC, Canada
What I Drive: 1985 Moto Guzzi T5 850 NT
FF Reputation: 1
Buy-Sell-Trade Rating: (0
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.
I have learned that I can (temporarily) disable the three systems -- ESC, TCS, and ABS (but keep the electronic brake force distribution intact.... i.e. the rear wheel brake proportioning) if I cause just the ABS logic module to fault. That means that I would turn the car, on a switched-in and switched-off basis -- to a car without ABS, TCS or ESC... but with proper rear wheel brake proportioning. I suspect that this would be OK, for the ocasional DE day / track event. Incidentally, I should mention that to selectively switch-off TCS, or ESC (individually) and obviously keeping ABS fully intact all the while, is apparently a major ABS ECU programming hurdle.... that few if any folks would be able to accomplish. That's why I talk about simultaneous loss of ABS, ESC, and TCS.
The four individual wheel ABS sensors / tone rings have to remain operable, and the two (?) Hydraulic Control Unit (HCU) solenoids have to remain functional. But the ABS logic module has to fault.
I suspect that I could have the Printed Circuit Board (if this is easily accessible?) modified, so that I can introduce a break in one or several printed circuit tracks...and lead that same break... out of the unit in the form of insulated wires, to a switch (that is made electronically clean, using some kind of voltage spike quelling circuitry... a capacitor or??).
This would constitute a systems on or systems off switch.
Then, I could add-in the amount of front versus back roll stiffness that I desired... and thusly could tune the suspension... without the ESC system intervening. Remember, if the ESC intervenes, it can leave you with a momentary loss of power...
As well, the TCS would be my right foot... not the electronic nanny.
Ideas, anybody? ... but please, please ABS zealots need not preach on the ills of not having ABS under these circumstances... What did people do before ABS was invented? Would those strong ABS advocates NOT buy a classic car (without ABS)? I, for one, would never buy a new or newish car without ABS... but as for TCS and ESC that is not cancellable... I have a problem!
Many thx for any / all who answer!