On my 2004 Dodge Dakota I have an engine light code 740: transmission trouble. Local mechanic wants $600 bucks to change out the solenoid ($350 for solenoid, $250 labor), he says that's the problem because the transmission shifts fine. I disconnected the battery and the light clears until I've gone about 20 miles, then it comes back on. I changed out the filter, not much metal fines on the magnet, and I didn't see anything that looks like a solenoid in the pan. Where is it and is this something that can be replace without going into the transmission internals?
I appreciate any help and advice. Thanks.

 

the solenoids are in the transmission's valve body. Do you have a code for what solenoid is bad?

 

P0740 is "torque converter clutch, no rpm drop at lockup."

TCC solenoid.

What engine/transmission do you have?

 

that could be a failed solenoid or a fried/roasted/deepfried/broiled TC clutch itself, which is what happened to me...then took everything else with it.

For optimism's sake, lets assume it's only the solenoid.

 

I've got the 3.7 with the 4 speed auto, it's a quad cab. I bought it about two weeks ago, the light was on then but the owner said his mechanic had said the code was for transmission overheating and since it wasn't hot he thought the light was faulty. The guy I bought it from didn't seem too mechanically inclined and he was elderly. I've never worked on an automatic transmission so where is the valve body and is this something an average shade tree mechanic can tackle or not? I'm digging out my receipt from the local mechanic, give more details in a minute. And thanks!

 

In labor description "Check transmission, light on, Computer test (code PO740), test TCC, working OK, clear codes and retest. So I drove it home and on the way the light came on again, I called the mechanic and he made the statement about the solenoid and that's all I've got. The charge for that was $93.50 and I had already had that done at AutoZone for free, but I took it to this guy to try and find out more about what the problem was. He cleared the code, test drove it, and sent me on my way to have the light come on again.

 

Maybe, just maybe, it's a different code. You don't need any tools to check codes on your Dakota. It can read them for you.

With the key OFF, turn it to RUN (don't start the truck). Then back to OFF, then to RUN, back to OFF, and this time LEAVE IT in RUN.

Codes will display in the odometer window. It will show P DONE when finished.

A failed torque converter clutch, or one slipping, can lead to overheating.

 

Thanks 00DakDan, Okay, I'll check it tomorrow (10pm here). When I changed the filter I could pretty much tell it hadn't been done in a while, but the fluid smelled okay and didn't look too terribly bad. Some amount of metal fines on the magnet but not a terrible lot, and there was some "sludge" in the bottom of the pan but not a whole lot. I'm wondering now if the mechanic said "solenoid" or "sensor", I'm not sure anymore, does a solenoid have electrical wires (he mentioned something about wiring harness) and does changing a "sensor" make more sense? and would this be a two screw affair and relatively simple? I'm assuming the valve body is the first thing you see with the pan off and where the filter is with about a million bolts and screws, I'm not sure I want to mess with that. This truck has 175,000 miles and looks great and the engine runs really well, I got it for $2k. It's been neglected and not kept up but I feel at that price I can put quite a bit of money in it and still get a lot of good use out of it. I'd like to have a simple fix if possible, but before I spend $600 on a solenoid, I rather go with a remanufactured tranny and replace the whole thing and I can do that myself.

 

if in fact TCC, it's a pretty simple good-fail system. If it works, the engine falls 300 RPM when engaged. If it doesn't, it doesn't. The engagement and RPM fall should occur about 1 second after the 2-3 shift completes. If you hold a constant throttle in 3rd or 4th and just lightly tap the brake, you should see on the tach the TCC disengagement because the RPM will come back up 300 or so.

 

Good morning! I checked the codes in the odometer window by turning the key on and off like 00DakDan said, I got a P0440 and a P0700, then P done. I haven't checked the RPM's yet per magnethead, I do remember the mechanic saying it wouldn't hurt anything to continue driving it with the light on, that all it would do is affect my gas mileage a mile or two. I'm just one of those folks that wants everything working the way it's supposed to and will try to get it back to it's intended state if I can. That "check engine" light on is driving me crazy !