DFCO Explanation Help

[Kevin Doe]

Ok, when looking at all the DFCO settings and curves I'm highly confused.

Lets start with the parameters section:

B3307 DFCO Re-Enable Timer
B3308 DFCO M6 Enable Temp
B3309 DFCO M6 RPM
B3310 DFCO M6 MAP
B3311 DFCO M6 TPS
B3312 DFCO M6 Speed
B3313 DFCO Temp Enable
B3315 DFCO Vehicle Speed Hysteresis
B3317 DFCO Throttle Hysteresis
B3319 DFCO RPM Hysteresis
B3321 DFCO MAP Hysteresis

1. What is the difference between B3308 DFCO M6 Enable Temp and B3313 DFCO Temp Enable?

One description says, "Engine coolant temperature must be above this to allow DFCO M6 to occur."

The other description says, "Engine coolant temperature must be above this to enable DFCO.

When all of the DFCO enablers are met, hitting any DFCO activate level will turn on DFCO. After DFCO has been enabled hitting any DFCO disabler or hitting every DFCO deactivate will turn off DFCO."

That leads me to believe that DFCO and DFCO M6 are different things. Stock calibrations for a LS1 GTO are 140 degC for the former, and 70 degrees for the latter. That means that DFCO M6 should never be active based upon B3308. But I know that it in fact does work. I'm confused.

2. There is B3312 DFCO M6 Speed, which has the description, "Vehicle speed must be above this to allow DFCO M6 to occur." This is set to 322kmh stock, which means DFCO M6 will never be active.

Then there is the table, "B3314, DFCO Vehicls Speed Enable. Why are there two speed enable places? A table and a single parameter. Whats the difference?

3. The same goes for RPM, MAP, and TPS. They all have tables AND single adjustments.


I'm thinking that DFCO and DFCO M6 are different things, but I'm not sure since there isn't really any description of them.

Also, can someone explain the activte/deactivate enable/disable stuff to me. So enable means that DFCO is allowed to occur, and activate actually turns it on?

[joecar]

The one's that don't mention M6 are for A4.

[Kevin Doe]

Why then is it that the M6 ones are disabled by setting the parameters out of any possible range on a stock M6 GTO tune?

[Kevin Doe]

Sorry for the extra post, but the edit isnt' working for me.

On the stock M6 GTO tune, the M6 DFCO parameters are set out of any possible range of enabling/activating. However it definately enters DFCO on deceleration. Its using the non M6 paramters and tables it appears.

[dfe1]

The M6 parameters pertain to DFCO during gear changes. Many factory calibrations have M6 DFCO turned off for whatever reasons the engineers feel appropriate.

[TAQuickness]

DFCO M6 is a feature to activate DFCO on M6 vehicles based on clutch activiation. It works in combination with the non-M6 DFCO settings.

I believe the intent of DFCOM6 was to save a few drops of fuel while the clutch was depressed.

I seem to recall disabling DFCOM6 in my tune due to drivability issues.

[mistermike]

It would seem to me that you'd be asking for some stumbling if you enabled DFCO during a clutch disengagement. Not much to keep the engine spinning.

[Blacky]

Also, can someone explain the activte/deactivate enable/disable stuff to me. So enable means that DFCO is allowed to occur, and activate actually turns it on?

The short version:

ALL enablers must be satisfied AND ONE or more activations need to be satisfied for DFCO to become activate.
Only ONE disabler OR ALL deactivations need to be satisfied for DFCO to be deactivated.

Edit: ALL enablers/disablers means Throttle, RPM, Speed and MAP enablers/disablers.

Regards
Paul

[TAQuickness]

It would seem to me that you'd be asking for some stumbling if you enabled DFCO during a clutch disengagement. Not much to keep the engine spinning.

yeah it's quirky. Wasn't much of a problem for me until I added a bucket of lightness to my rotating assembly. Biggest problem I had with it, the engine would spin down way to fast for my liking. Disabling the M6 function made it just right ;)