Truck flashed this code last week and wouldnt go into gear. FInally got it to go into gear and it was in limp mode. Swapped trans pressure switch yesterday that bolts on valve body and truck still flashed code but we cleared it and truck shifted so smooth. Fast forward to this mornign and check engine light and limp mode is on. Trans wont go into gear or anything. I am lost. I have traced wires and everything I could think of. I am so frustrated with it so I figure I am gonna take it to a trans shop. I hate to pay people to work on my truck but I figure it is best. Cant figure the issue out.
PO8077 P08078 Code
- Thread starter MaxComp88B
- Start date
Have you checked the easy stuff? Fluid level ok? No fluid in the pass through connector on the trans?
Yep. I did a fluid change a few months ago with external and internal filter and just did again yesteday since I was in there. Yes level is good.
did you change the internal harness as well or only the PSM? i understand the connector may not be leaking but doesnt rule out the internal harness. specially if when you put everything back in, it was all good for a while, then the code came back. something may be getting a bad connection.
watching a scan tool while watching PSM with KOEO while you move wiring around under there can tell you if its a connection issue
watching a scan tool while watching PSM with KOEO while you move wiring around under there can tell you if its a connection issue
Thanks guys! I did all of the stuff mentioned and nothing worked. Finally sent it to a shop and they think it is the tcm and there is something going on inside of it. It didnt have a loss of connection code but it had shift range inhibited and wouldn't go into gear and hard shift. But now we ar having an issue finding tcm's as they are sold out in a lot of places.
Just tell shop or yourself to order from dealer. They can SPAC case a back ordered part to see if anyone in the country has one and will sell it. But, if it’s on national control than dealer has to order it and just wait. Last one I did a month ago only took about 1 week to get.
They have ruled out TCM and belive it is farther intot he trans in the internal harness. It is frustrating not having the truck.