Quote:
Originally Posted by dodgeboy16
Sorry I don't want to beat a dead horse here but what I'm saying is that MY 2008 GCSRT8 is shifting to soon between 1st and 2nd at WOT. Since what ever causes the Trans. to shift is not looking at the Tach. than what is telling the Trans. to shift to soon or even to shift at all. Could the TCM be the culprit?
Jack
|
The engine controller puts rpm on the bus. ABS puts vehicle speed on the bus. Trans module uses this data, along with internal trans sensors, to shift according to a pre-defined schedule (with a slight amount of vehicle-to-vehicle adaptive learning included). The tach value you see in the cluster is pulled from the bus (same signal the TCM uses) but filters the signal so you won't see annoying dither. Because the GC can accelerate so fast in first, usually from an idle launch, the tach has the furthest to travel and the dampening effect is more pronounced. Do you notice more dampening when cold? There is an oil filling in the cluster that provides a mechanical dampening effect (in addition to the digital filter).