1999 Grand Voyager 3.3L Transmission Error Code P0740

The transmission is working fine. The van failed state inspection. Would Autozone be able to tell me exactly what needs to be repaired or do I need to bring it to a transmission shop? Any recommendations for a shop in the Lehigh Valley area (Allentown)? Thanks

torque converter lockup not locking up. Autozone would be totally clueless about this one.

if you plan on fixing this yourself, you will need a scanner, factory service manual diagnostic routine for problem solving the TCC and a hydraulic pressure gauge.

possible problems: bad torque converter clutch, leaking seal, worn pump bushing, solenoid pack, solenoid shift valve,

...or just reset it and see if it comes back.

We reset it twice and it came back on twice. There is a small red leak near the radiator on the driver's side...could this cause it? I want the diagnostics so I don't get ripped off. Any suggestions re who to go to...dealership, specialty shop, or local garage.

My friend has a 1997 Dodge Caravan with this same problem... The Torque Converter clutch circuit has a problem, but it may not be fixable in your case, as in my friend's case... However this does depend upon what was done already...

Do you have VERY high mileage???

My friend's tranny has 190,000 on the ORIGNAL tranny... Also, some tranny rebuilders are crooks and they REUSE your torque converter, therefore, your torque converter clutch may have a TON of miles!

About 30,000 miles ago, we changed the solenoid block (which has the Torque Converter solenoid in it) and I rebuilt the valve body with as much updates as possible... Then we got another known working computer for the transmission and that didn't solve it either... Those are the 3 things that it can be before saying it's the clutch itself...

The the same code comes on for him, so it is evident that the Torque Converter clutch actually wore out... In NYS, inspection DOES NOT fail for THAT code, because it is a NON-emissions related code...

HOWEVER...

We still don't like taking it for inspection with the light on, so we will RESET the codes and then ONLY drive 30 MPH until the MIL status is ready... By doing that, the light won't have a chance to come on because you haven't reached highway speeds... THEN we go for inspection and it always is not a problem...

It is VERY possible, you have something else wrong, because what I have here is rare and I'm kinda waiting for the day that this tranny needs a rebuild; it's almost comical...

Anyway, if the solenoid itself is bad, you can replace the solenoid block, in which you can find them for less than $100, I think I have bought them for $75-$80 most recently... Overall, if your tranny was going to last awhile, changing the solenoid block will only make it last longer and shift better with less "buzzing" noise... If you end up needing a rebuild, you will at least, already have a new solenoid block for your new tranny...

Second, dodges have certain TSB's with most dodge vehicles about the computer needing to be reflashed, due to a "quirk" in the programming for the Torque Converter..

Barring something is wrong in the valve body (doubt it) that is related to the system, you can always try a bottle of lucas transmission fix; it can't hurt, and it may even allow the torque converter clutch to regain friction and start to reapply again, be it, even if only for awhile...

Hope that helps,
Mike

As far as the leak goes, you may only have a little leak at the tranny lines that screw into the radiator... If you had a new radiator recently, maybe the guy didn't tighten it all the way or the hoses are getting old and dried up...

Another thing is, IF you have an external cooler, it may be leaking; I have seen them get broken in accidents and rusted out somewhere...

you definitely need a real scanner and factory service manual for proper diagnosis.

Based on recommendations I brought it to an independent shop Dynamic Transmission in Emmaus. Based on all your help and my research he knows I am informed. I will post the results when the diagnosis comes in. Thank-you

I have a 2002 Caravan with 230,000 miles on it, about a month ago the wife said the check engine light came on, checked it and found the P0740 code. After driving it I could tell that the converter was not locking in, other than that, seemed to drive fine, that was about 1500 miles ago. She called me yesterday (im out of town for business) and the trans is now gone, she barely made it home. From what I have read, when you get that code, the clutch inside the converter is slowly breaking apart and will kill the transmission.

I cant find where I read this, but if the solenoid pack was the problem, it would be in limp mode, since it does shift normally (just no lockup) the problem is more than likely the converter itself.

I am not complaining about having to rebuild it, after 230k, I got my money out of it, I may even buy a couple of books and attempt to rebuild it myself.

I have a 2002 Caravan with 230,000 miles on it, about a month ago the wife said the check engine light came on, checked it and found the P0740 code. After driving it I could tell that the converter was not locking in, other than that, seemed to drive fine, that was about 1500 miles ago. She called me yesterday (im out of town for business) and the trans is now gone, she barely made it home. From what I have read, when you get that code, the clutch inside the converter is slowly breaking apart and will kill the transmission.

I cant find where I read this, but if the solenoid pack was the problem, it would be in limp mode, since it does shift normally (just no lockup) the problem is more than likely the converter itself.

I am not complaining about having to rebuild it, after 230k, I got my money out of it, I may even buy a couple of books and attempt to rebuild it myself.


found you a trans in Swanton OH for $200 with 80K. cheaper than a rebuild.

I might be insterested in that, where did you find it at? I searched car-part and it didnt return that particular one.

the trick is to know what you are searching for. I'm am a master at circumventing the rules. just so happens a stratus trans will bolt righ in, hook up and the only thing you need to do is change the diff housing for the passenger side axle... that's it.

Learn something new every day, I knew most of those transmissions were the same, didnt know the one side was different. I am probably going to rebuild mine, if I ever get home.....

Learn something new every day, I knew most of those transmissions were the same, didnt know the one side was different. I am probably going to rebuild mine, if I ever get home.....
they are so easy, I watched group of highschool kids rebuilding them

you definitely need a real scanner and factory service manual for proper diagnosis.

Where can I get a good scanner, how much are they and what brand is best for the $$

A good scanner that can do bi-directional tests will cost thousands and really isn't needed by a regular joe. As for a code reader, get the cheapest one you can find since pretty much any OBD2 code reader will read all drive train codes for a domestic vehicle. I wasted my money on a Snap On ETHOS for just under $2K and the damn thing cannot even perform tests.

A good scanner that can do bi-directional tests will cost thousands and really isn't needed by a regular joe. As for a code reader, get the cheapest one you can find since pretty much any OBD2 code reader will read all drive train codes for a domestic vehicle. I wasted my money on a Snap On ETHOS for just under $2K and the damn thing cannot even perform tests.

There's no other scanners out there that don't cost 1000's and allow bi-directional communications? Snapon ETHOS list price is under $1000. How about a used scanner? Would that be a good way to go? I can get a used Genesis for $300 with cables and chips goes up to 2006.

Or would it be stupid for me to own a scanner so I can fix my own stuff?