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4l65 TCM will not command shift to 4th
Hello all, Im a little new here so please be gentle with me LOL!
Like the title says this TCM will never command a shift to 4th if engine is running. You can command all 4 gears with the engine off only. With the gear command test, the solenoids A and B respond and current gear pid changes and you can hear the solenoids click in the trans with engine off. 1, 2 and 3 all work fine but the TCM never trys to shift to 4th and the only way I can get 4th to ever happen is with engine off with scan tool or VCM scanner gear command test. Both tools gear commands do not command when engine running and only work when engine is off. PRNDL shows correct D4, VSS shows correct, no OD off input is present according to pids and it shifts up through 1,2 3 and back down 3,2,1 just fine but never will the tcm command 4th gear on its own? I have tried lowered RPM and VSS speeds with no luck at all. TCM never tries to shift to 4th even according to pids. Tune and data log attached if anyone can spot anything strange, I may not loose my mind........ today anyway! Gen 3 Camaro with 2008 truck 5.3 with 4l65e e38 with t42. Swap was done a few years ago, never finished and now its in my yard driving me slowly insane. 1st, 2nd and 3rd all work correct so with only 2 solenoids A and B that control all 4 gears, if the trans would command 4th it should go to 4th but TCM never does as data log shows :banghead: