I am sure this has been discussed before. I have a 2005 grand caravan sxt with the 3.8 motor. The other day when my wife had gone to town and on her way back the trans. would rev up to 4500rpm and wouldn't go above 25 mph. Had van towed home. Pulled codes p0734, p0700, and p0740. What do these codes actually mean? I had erased the codes and checked fluid level, which was a little low and put more atf+4 in took for a test drive. Everything ran just fine. drove up to 80mph and trans shifted just fine. Today there is a high pitch noise coming from the area of trans and motor. Where they are bolted together. With vehicle up on stands I put in reverse and then there was a grinding noise and the tires would spin like normal. They would stop like I was tapping the brakes, which I wasn't. Did same thing in forward. Does anybody have an idea of what is wrong? Am I going to have to replace the trans? Also I have trac loc button on stearing column. Does that mean I have trac control trans? Thanks for the help.
Matt B.

 

P0700 Transmission control circuit malfunction - It's just telling you the TCM has detected a fault and stored a code.

P0740 Torque converter clutch (TCC) circuit malfunction - Could be anything from a corroded electrical connection to a bad torque converter in the transmission.

P0734 Gear 4 ratio incorrect ratio - Can indicate slipping clutches or sesnor problems.

You could drop the fluid pan and inspect for debris. If there then it's time for a replacement or rebuild. You could take it to a shop and have them scan it and read the CVI values. They will tell you the condition of the clutches.

"The other day when my wife had gone to town and on her way back the trans. would rev up to 4500rpm and wouldn't go above 25 mph" Sounds like the TCM detected a failure and put the transmission into what's called "limp mode". It limits gears to 1st, 2nd and reverse.

 

Thanks for the reply Cougar41. I had figured it went into limp mode and you confirmed that. I did drop the pan and there is no debris, just some small sludgy particles on the magnet. How would I know the torque converter is bad? Could you please tell me the procedures to test the control module or the solenoid?
Thanks Matt B

 

If you have a scan tool that can perform a transmission clutch test and can see the CVI. After you have done that, then post the information.

 

Master Tech,
I do not have a scan tool to do that. Getting the CVI pressures is the only way to know if the clutch packs or torque converter is bad, that is without having the trans totally torn apart. I would like to take the valve body out, how do I do that? I have taken all of the non torque bolts out and still cannot remove the VB. Is there a trick?
Thanks Matt B.

 

After much checking things are good. I had removed the trans pan to see if there was any metal pieces. Thankfully none. After reading about the different electrical issues I had removed all connecters and cleaned and put dielectric grease on. Then called a local dealer and asked them some questions about test that I could do. The mechanic said to remove the connector to the TCC solenoid. He said if there are problems with it connected and then no problems when disconnected the issue is electrical. Also if the problem happens when disconnected then it is a mechanical. I had performed the test and got no issues either way. The only thing that I noticed when I changed the filter and added fluid was I needed to add 6 quarts of oil. In my manual, it said it takes 4qt with filter change. I have driven the van for 4 days now and no problems.
Matt B.

 

6 quarts - wow! I was interrupted when I did this job, and couldn't finish until the next day. Even with the tranny open and dripping for a full day, it still didn't even take 5 full quarts on the refill.
Are you certain the level is ok? Did you run it for a few munutes and use the "cold" marks to check the level on the refill? The vehicle has to be driven for quite a while before the tran fluid gets hot enough to use the "hot" marks. Perhaps it might be a good idea to check the level again using the cold marks, after just starting and running for a minute or two.
And you did use ATF+4, correct? (somebody always has to ask, so it might as well be me this time).

 

Yes I did use atf-4. I did run the van for a drive to make sure that it was good and warm when I checked level. Was a little nervous about the amount added. Did not add all at once. I added 3.5 qts first then let the van warm up. Only added a 1 qrt at a time until I made sure that it was at the top.
Matt B.

 

It's hard to understand how it could have gone 6 quarts down. The tranny fluid takes much longer to come up to full temp than an engine warm-up cycle takes. So, iIf you checked it using the hot marks, and didn't drive it for around 20-25 minutes, then chances are good it's overfilled. I suggest that you check it again by starting it up when cold, idle for just 1 minute, and then see if the fluid is inside of the cold (bottom) marks.

 

Well I am back to working on my van. It sat from Sept. 13' till a couple weeks ago. Wife went and bought a new car. Now van is mine to deal with. I just replaced the torque converter solenoid. Now the van does the rumble strip shudder when it shifts and I get the p0740 code. I am wondering if I am going to have to replace the torque converter, relearn tcm, or do a rebuild. Can any shop do the relearn or does it have to be a dodge dealer? What is involved in the rebuild? The van has 182,000 miles and is in decent shape. Any and all advice is welcome.
Matt