Derek Pedersen

Tried mine out on the way home. Seemed to behave the same way. Heat on full.... less engine braking. Turn it to cool.... more engine braking.

BHMav8r

Same symptoms - turn the heat on and the rpms lag - turn it off and they drop like normal.

Anybody have a clue how to fix this?

TIA.

frankvan

See my posts #22 and #28 in this thread. Cures the symptoms, and i don't think it's a disease, it's just the way the engineers engineered the CCU to interact with the DME. Drivability is much improved and so far there doesn't seem to be any problems...

Derek Pedersen

Just a hunch, but I've got an idea why the engineers designed it this way. While driving to work this morning on icy roads I realized how nice it was that engine braking was minimized when I let up off the gas. Let risk of spin out.

And the car can "tell" when its warm out by the state of the CCU. Less engine braking in the winter to minimize spin out. More in summer to maximize fun.

Just a theory.

frankvan

OTOH,
I like the engine braking when i enter an icy corner - more control than "touching" the brakes which always makes me nervous in these rear engine beasts. Scares the he11 out of me when i expect to slow down from engine braking and the car starts to surge seemingly faster.
What's interesting is that this is my 7th winter driving a c4 and this is the first time i've noticed it. (note, this is my second winter with this C4, and i actually didn't drive it that much last winter - maybe my previous C4 didn't do it?)