Took my 2003 Jeep Liberty 4x4 to dealer for 75K routine maintenance yesterday. Told me I needed transmission fluids changed (I had previously done this at 30 and 58K also). Yesterday and today noticed that it downshfted very rough at 30mph. Took it back in and dealer says diagnostic shows it lost it’s prime 34 starts ago (just about the time they serviced it!). I don’t trust them and don’t know what to do… did call Chrysler regarding warranty. What’s up with this?
“dealer says diagnostic shows it lost it’s prime 34 starts ago”
This is terminology with which I am not familiar.
Did they explain to you what this supposedly means?
Thanks for your reply. Apparently there is electronic diagnostic equipment used to pinpoint the time when the problem first occurred - 34 engine starts ago.
It doesn’t sound like the dealer is pulling one over on you. A good high end scanner or a dealership computer can give you that information. My scanner will give that information. My scanner also gives information like: Failures that occurred this ignition cycle, last ignition cycle, last time failed since the code was cleared, miles since code set…etc. As far as the servicing goes, it looks like you have been keeping the service up on it. Automatic transmissions need to be serviced every 25-30k miles. By servicing, I mean a pan drop and filter change and refill the trans. You’re not due for trans service for another 8k miles. If they said the only code they got was for a loss of prime then tell them to be sure to clear it and drive on out.
How can a transmission lose its prime? How do you “prime” a transmission? Why would a “lost prime” make it downshift hard?? Sounds like mumbo-jumbo to me…
Loss of prime means the filter in the pan was sucking air instead of fluid (low on fluid). This could have occured on startup after the fluid was changed.
Failure to achieve pump prime- code 35 in the TCM. Low fluid level with pump cavitation will cause this. What probably happened since the dealership found the code has been there for awhile is when it was serviced last the trans was drained and the engine started before there was enough fluid in the pan. A code 35 wont set limp mode so the harsh shifting which recently appeared is from something else. I recommend clearing the code 35 and driving the vehicle until the harsh downshifts start again then without shutting off the engine, take it to an auto parts store and have the computer scanned for any new codes. I still think the dealer is being straight up so far.