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View Full Version : WOT Shift at RPM or MPH?



johnmaster
July 12th, 2012, 07:59 AM
How does the PCM calculate WOT shifts? i.e. D0910 is WOT 1-2 Shift speed normal and D0940 is WOT 1-2 Shift RPM. Does it have to satisfy both to perform a WOT shift or either have to be satisfied?

Say I have it set at 5400 and 25 mph will it just shift when it hits 25, will it shift at 5400 regardless of speed or does it have to be at least 25 and at least 5400 to shift?

I'm confused :S

joecar
July 12th, 2012, 08:21 AM
Both have to be met.

johnmaster
July 12th, 2012, 08:34 AM
So to ensure full rpm is met in each gear set the mph significantly lower than what it should be at each gear?

Thank you Joe!

ScarabEpic22
July 12th, 2012, 08:35 AM
Both RPM and VSS conditions must be met, I set the WOT shift values the same as the 100% column in the normal shift tables to make it easier. I messed this up a few weeks ago and didnt set the RPM point correctly, was supposed to be 6000 and was set to 6500 (what my truck is set to). Needless to say, the truck I was tuning bounced off the rev limiter until I told the customer to back off. Doh! Got it fixed the next revisions about 2 min later though.

In your case, if set to 5400 and 25mph, you will cross the MPH parameter first then the PCM/TCM will wait until the 5400rpm parameter is met. Person preference, but I like to set the mph point a little lower on the 1->2 and sometimes on the 2->3 shifts so the MPH param is met and the TCM waits until the desired RPM then shifts immediately.