Upshifts Too Late, Downshifts Too Soon In One Truck But Works Great In Another

[joecar]

The other problem is that your PT shift tables cross (in four places)... they should not cross anywhere, see attached graph:



At any TPS % value, the order of the shift table should be as follows
(from top to bottom as you look at them stacked onto the same graph):
3->4
4->3
2->3
3->2
1->2
2->1

Do the same with WOT shift points.

PT shift table relationships:

basic relationships:
1->2 curve should be above 2->1 curve;
2->3 curve should be above 3->2 curve;
3->4 curve should be above 4->3 curve;

additional relationships:
3->2 curve should be above 1->2 curve;
4->3 curve should be above 2->3 curve;

this can be summarized as: the curves cannot cross anywhere;

if they cross anywhere, then you will not be able to predict what gear the PCM selects when the operating point hits the cross.

A4 shift table spreadsheet is here.