Hello. I have a 16 cascadia with dt12. Recently my truck started to rev when I would shift from even # gears to odd # gears. Ex 8-9 10-11. But doesn't rev when shifting from odd gears to even gears. Or even odd gears to odd gears. Any idea what this could be?
Hi. The same. Did you resolve it? As for me - did already program update - no changes. Mechanic connected to truck and checked for faults - all is good. Why did you think that the problem is connected with air?
My 16 Western Star with DT12 is doing the same. A friend of mine has software for troubleshooting, we did a transmission and clutch relearn but it did not change anything. Next thing I will do is check wiring harness to TCM and pins to make sure there is no corrosion.
For Engine RPM flare during up shifts, first you need to make sure you at least 100 psi air pressure to transmission and don't have air leaks. If you have air leaks fix before going on. Next do road test with Diagnostic Link log Actual Engine Speed, Countershaft Speed and Actual Gear engaged. After test drive you review the log file and if the engine speed flare is there. Next steps is to remove the transmission and rebuild the Counter shaft brake.
For those who are having the engine rev during up shifts I am attaching the diagnostics steps that the transmission manual says to do for engine rpm flare during up shifts. Seems like the diagnosis would be inexpensive. The cost would be in the repair.
Thanks for responding, why would it only flare up on even to odd shifts and not odd to even shifts? Is there something in the transmission that controls only the even to odd shifts?
Thank you. After I originally posted this my problem went away. Now just recently it came back. Thank you for help
