My 01 T&C has 98k miles, two days ago the engine light came on while driving at highway speeds. I have been reading through past forum post and have a few questions I hope that some experienced T&C owners and or service techs might be able to answer for me. I was able to get the P0700 code through the odometer area. I have not taken the vehicle for any service yet. If my tranny is still running smoothly and showing no signs of malfunction, is it safe to say the problem is most likely the torque converter? How long can the vehicle be driven (miles and at what speeds) before this can cause major problems with the tranny? I know that I will have to have the TCM read before I know the exact problem, unfortunately I will have to wait a week or two before I can pay for the repairs. If this is my problem I understand that the tranny hasto be dropped to do the repair. What kind of price am I looking at? Would really appreciate any answers or advice before I put myself at the mercy of the service personnel....LOL. Thanks.

 

I just had the torque converter problem last summer and replaced it myself, so I'll relate my experience here--

1) P0700 means only that the TCM (transmission control module) has stored a trouble code. AutoZone's code reader will give you the TCM codes and they'll do the read for free. The torque converter code is P0740. Your best bet would be to get the actual code you have in your TCM.

2) If your tranny is running fine, don't let anyone convince you that you should try replacing the solenoid valve pack. This will just be a waste of your money. The solenoid that activates the converter clutch also activates the L/R clutch, so you would have problems with your low gear if the solenoid pack was the problem.

3) You can drive the van as much and as long as you like with a bad converter clutch. We drove ours for 4 months, including long trips,before I found the time to fix it. The only limitation is that you will not be able to pass an emissions test until it is fixed. In theory, (and people may tell you this) the tranny will run a little hotter without the converter clutch. I have the dealer scan tool (DRBIII) and took it with me on our trips to keep an eye on this-- the tranny never even got close to overheating.

4) I've heard of tranny shops telling someone that they must rebuild the tranny because of converter clutch friction material poluting the tranny. This is BS, the filter will catch most of the clutch material, so the pan should be removed and the filter should be changed at the time of service.

5) If you have lots of miles (in the 100K range) you MAY want to consider getting a "rebuild" done on your tranny (new clutches and seals) while it is out of the van given the expense of just removing it and reinstalling it. We only had 57,000 miles on the van at the time and the scan tool (which can measure clutch volume-- called the CVI index) showed that all of the clutches were well within specs, so I decided it wasn't necessary to rebuild. I did replace the front seal on the tranny since it was easily accessible and only took about 15 minutes.

 

Thanks Rick99, I will definetly have Autozone get me the TCM codes before driving to much on it.

 

they cant give u the TCM codes only generic federal emmisions codes U will haft to go to a dealer or tranny shop and hook up a better scanner to get the codes.

 

ChryslerTech-- that's not true. I was away from home when the light first came on and when I got the P0700 in the odometer, I stopped by an AutoZone and their reader did give me the P0740 code. Maybe it won't give all of the TCM codes, but it did give that one.

 

the 740 is still a generic federal emmision code still wont tell u what whats wrong with the tranny.

P0740-TORQUE CONVERTER CLUTCH CONTROL CIRCUIT

 

True, if you have a p0740, it tells you onlythat the set conditions for that code have been met. Specifically that the computer detected a difference between the engine speed and transmission input speed of greater than 60 RPM when the van was driven over 50mph with the TPS (throttle position sensor) at less than 10% and the converter clutch commanded to lock. The RPM difference shows that the engine and transmission input are not "locked" together by the converter clutch.

So, the problem could be (1) a failure of the TCM, (2) a bad electrical connection between the TCM and the transmission, (3) a problem with the solenoid pack, (4) a problem with thevalve bodyor (5) a worn out/failed converter clutch.

Since the transmission is otherwise running perfectly, that gives me a strong suspicion that 1,2,3 and 4 are not the problems, but before prescribing a big job like replacing the converter clutch, a little test would be in order.

If you have a p0740, you can isolate the converter clutch by doing a pressure test. Attach a pressure gauge with a long hose to the converter clutch pressure test port on the front of the tranny just below the solenoid pack (the gauge costs about $50). Tape the pressure gauge to the windshield wiper and go for a little test drive (preferably with a buddy driving and you watching the gauge.) The gauge should read about 100psi until you get on the highway in a long straight and flat stretch with the van travelling greater than 50mph and the throttle only slightly pressed, you should see the pressure drop to below 5psi. If that happens and there's no engine RPM drop on your tachometer, you've just ruled out problems 1,2,3 and 4.

This test, of course, is just to confirm what is the most likely cause of the p0740-- since this is a very common problem with these vans.