I don't know if we are experiencing the same problem. I saw a TSB in the NHTSA website telling about the replacement of the secondary clutch pack for the 4T65E transmission. If only I could get a copy of it.
What I am experiencing in my van are hardshifts after the vehicle is driven for quite some time. When you turn off the enging, it goes back to normal shifts. I already replaced the transmission fluid (80,000 kms) and filter about a few weeks back. I've seen in previous threads that it might be a faulty MAF or a stuck PCS. I tried to pull the codes but there aren't any logged in the PCM. I already cleaned the MAF. I've backprobed the MAF yesterday and it showed 4.45 V while the engine is idling. Is this the correct voltage that I should be getting from the signal side of the MAF? Or is this the correct way of testing the MAF? If not, can anybody tell me how to test it properly?
If this is a PCS problem, shouldn't it be that there is a code of P1811 in the PCM?
I am really stuck as there is no DTC logged and really can't pinpoint the exact area of the problem.
Any help from people out there would be really helpful as I am still out in the dark.