Hello all,

I have spent days reading here and elsewhere to find a solution because I didn't want to get the infamous "been covered, search for it" response. Nothing quite like mine. So here goes: 2003 Sebring DOHV 4 cyl.

First no engine light, no codes (check engine light works with key on, no stored codes). Purchased car last week no real history. It had sat for 6 months with a dead battery due to needing a water pump (turned out to be a hose had a hole). Drove fine when I left the sellers address. After about 10 minutes it began to hold each gear a very long time and I figured out if I let off the gas slightly it would shift. Used this method to get home although it several times had trouble getting to 50mph. it does eventually get there if you don't try to rush it (as in turn on hazard lights and get honked at). If you accelerate it just holds the gear or downshifts. Steering wheel shakes a little at idle and gets worse as it gets warmer (stop lights). Since owning it, I have learned the following about the symptoms. If I shut the car off for a few minutes it acts normal through 1 or 2 take offs. Then reverts again to acting up. I have no reverse issue, speedo works fine. Car temp is normal. I replaced input/output sensors...no change. Replaced shift solenoid....maybe a little worse then before. Fluid is red and clean. Plan to change filter and atf+4 tomorrow. Think TCM is the issue? Is it trying relearn? Any help would be greatly appreciated.

 

If you've changed the fluid and filter and the input and output sensors and the solenoid pack, you've done pretty much everything you can do on your own with the transmission. It may be going through the "learning" process but, frankly, it doesn't sound like it. The learning process results in some rough shifting, not a complete absence of shifts.

Usually, if the computer fails it will generate some sort of code. You'll need a sophisticated code reader to get to it, but it will show a generic code indicating that there are more codes stored. With the poor shifting you describe, there ought to be some codes in there somewhere. It might be getting to be time to get it into a transmission shop to get some proper diagnostics run on it. Be sure to tell them what you have already done so they don't repeat it all.

Oh, one more thing. Removing the pan and changing the filter results in draining only about 40% of the fluid. If they put the wrong fluid in there before you got the car, some weird things could happen, so if you suspect the wrong fluid, try to get as much of the old stuff out as you can.

 

Thank you for your input dcotter0579. No change after filter and fluid. I did note today that it didn't revert to shifting poorly as quickly as it had the previous days. But it did eventually do it. I have an appointment with the dealership tomorrow to quick learn the tcm for 57.00. I've put this much in, might as well go 1 step further. I have a nagging thought that maybe it isn't the tranny's fault at all. Maybe it's the engine? The fact it sat so long supposedly needing a water pump makes me wonder if when the fluid leaked it may have gotten hot and damaged the engine. I wonder if lack of compression from a head gasket might cause the tranny to hold a gear because of the engine speed sensors? Or vacuum (showing my age). It most of the time has no trouble rapping to 4K or higher if I let it, but in higher gears or when really acting badly it likes to hold 3K rpm. What might have been damaged by excessive heat which causes a loss of power besides head gasket? Will get quick learn first, but just curious as I ponder this through as far as junking it verses fixing it.

 

I wonder if your transmission computer has a problem with warming up. Sometimes a marginal solder point on a circuit board will operate just fine until the board warms up a bit, expands and "stretches" the joint enough to lose the continuity. You can replace the computer using services that operate on the internet. It costs something like 20% of what the dealer would charge for a new one and is relatively easy to do.

Here's one such source. There are many others:

https://carcomputerexchange.com/

 

Here is the latest update. Had the Chrysler dealer "quick learn" the TCM and he basically told me in advance that I was wasting 57.50 as it seldom changes things. His statement was that minor shift issues can sometimes be resolved, but mine would likely not be. He was right. Same driving out as driving in. But at least I know the TCM is functioning and not the culprit. No codes in the TCM. Driving home from the dealer (a long way from me) I lost basically all horsepower. As the car got warmer it shifted worse and worse and I wasn't able to keep up with traffic. Even the slightest hill, like an overpass, I would slow to crawl with engine rpm at 3K (3-4K seemed max no matter how much pedal)and first or second gear barely rolling along. Engine sounded guttural going uphill. If I tried to maintain or speed up the car would shift to 1st and higher rpms. Downhill it will shift and eventually pick up speed. I had to drive on the shoulder with hazard lights on at any small incline. I live near Tampa so we're pretty flat here. Eventually, when stopped at a light the engine stalled but restarted ok with a shudder. If I stopped and shut it off for even a short time the car would do better for a few minutes although still poorly. I'm really wondering if what I have is an engine problem. Perhaps the tranny is doing the best it can with what horsepower is being delivered. After this long fiasco the car cooled off and I drove it to the store and it shifted perfectly for 1 or cycles and then when warm it again began same problems. Temp gauge is dead center and no boiling in overflow. I must say though that it seems pretty warm under the hood. Not very scientific I know, but the hood prop rod will burn your fingers. I have put cleaner in tank and in oil and been through a tank of gas. Oh, this thing sucks a tank of gas in a very short time. Half a tank in 20 miles yesterday. Tried high octane with no change. Just a reminder, the A/c on makes the condition worse. I thought perhaps because of the draw on the alternator but now think perhaps it draws away more horsepower? Will get some carb cleaner today and look for vacuum leaks around hoses and intake gasket. Was thinking perhaps replacing pcv (by the way there is some blowback at oil fill but not ridiculous), cleaning throttle body (what do you think of seafoam?). Perhaps general tune up items like plugs and air filter. Pretty much guessing here. I ordered a laptop OBD2 cord and software will be here monday. Maybe then can post actual data which may help.

 

Almost forgot...the cooling fan and the a/c fan both come on cycling. A second or two on then shut off for a few seconds. Swapped both relays with the fuel pump relay and same action regardless of relay. Just seems a very short "on" period.

 

The cooling fans come on only occasionally as called for by the computer. If the dash gauge is not showing overheating then you don't have a problem there. If the driveability problems are showing up when the underhood temperatures rise, then, again, you may have the problem described in my previous post.

 

If you are indeed using that much fuel there's no way your car would be driveable. Your spark plugs would be so fouled up that it would be impossible to maintain any sort of speed. I don't see a transmission issue causing that type of fuel usage. Pull your spark plugs and see what they look like. I suspect that they will be black from carbon and probably wet. If you fix your fuel issue your other problems may just go away. My suggestion is to remove the plugs. Either clean them very well or replace them and take your car for a short drive. If everything seems good for a short time and then gets worse come back and remove the plugs again. If they are wet then your computer can't regulate the correct air/fuel ratio. You may have a sensor that has gone haywire. Did the dealership do a complete engine diagnostic or just the transmission. That's something that would've shown up right away. You mentioned that the car sat. Have you checked the air intake to make sure no critters have built a nest that may be blocking your airflow. I know it sounds far fetched but I've seen it happen before.

John

 

First of all want you to know I appreciate y'all. Whether we fix it or not it was considerate of you to help. As far as gas....I filled it to halfway point before going to dealership and was at 1/8 on return. Lots of lights between me and them (not a typical highway - us 19 in florida is a very congested 4 lanes each way blvd basically). They just read the TCM as they wanted 250 to read other codes for diagnotic purposes. Autozone and Advance Auto readers had already told me no codes. I didn't actually check the intake itself for critters, but the air filter was intact in the air box so not sure how anything would get in there. Also the throttle body is closed when off...though I suppose a strong critter may be able to push past. Will peak in and see. I did check the airway from the air box to the the throttle body and it was clear. I will check the plugs. I have noticed when running poorly I can floor the pedal with little to no reaction until it's to the floor and it quickly high revs and downshifts. Leaning TPS at the moment.

 

New plugs. New wires, new MAP, cleaned throttle body. New filter. Runs a lot smoother at idle and lower rpms at idle. Still warms up and shifts same as above. So I guess I'm down to TPS and tranny is just jacked....oh, and also need to pull O2 sensor and see if plugged cat is doing it. Will do O2 after it cools off a bit (summer in florida) and see if I can rule out the cat.