This is an intermittent (and very annoying) problem.

I have a 2000 Dodge Durango SLT 4.7L. It has 218k miles on it. This seems remarkable, but most of them are highway miles.

Every so often, and with increasing frequency (5 times in August!) my truck will lose acceleration power when increasing speed from a stop position. It will happen suddenly, sometimes straightaway when i have just started the engine and am pulling into traffic, and at other times it will happen after i have been driving for a while. I will stop at a light or something, and when I go to accelerate it just drags. Almost immediately, the engine light will pop on.

After I restart the car, the acceleration problem will go away and my truck will drive as usual. The engine light will stay on for two or three days before turning off, and the truck will run perfectly until its next sudden episode.

This has been happening for a little over a year. About 12k ago, last November, I replaced the transmission entirely (I at least paid for a new tranny - no guarantees as this has killed my trust for my local mechanic). The problem reduced in frequency but did not stop entirely.

Getting an engine flush also briefly reduces the frequency of the problem but does not eliminate it.

When I took it back to the shop, they told me the car was "just getting used to the new transmission." I may be a girl, but I know more about cars than to buy that!

I have taken it to five shops altogether; no one can seem to solve this problem. The computer gives the error code P1781: Manufacture controlled Transmission. This, as I understand it, is a generic transmission error message.

I researched error codes, and I found that 0781, which is very similar, seems to best describe what is happening. the is the code for a 1-2 shift malfunction. It feels as though the truck is having trouble shifting between first and second when accelerating. When i tell this to any mechanic, they tell me i need a new transmission without even looking at the car.

I already paid for one new transmission. I don't want to have to do that again. I love my Durango; it has been a very reliable and comfortable vehicle, and has given me years of great use, except for this issue. I really just want to fix the problem, I just don't know how. If anyone has any insights or experience with this matter then please help!! I really don't want the problem to develop into something worse.

 

When was the last time you did a tune up on your "D", Spark plugs, wires, oxygen sensors, and so on? what brands did you use for the tune up? 218k is remarkable mileage. The mechanic who said " It's just getting used to the new tranny is not the one I would trust. Does the "D" ever back fire? Using engine flush frequently is not a good thing. You may have a good bit of sludge built up. Or may be the shop that installed your tranny may have ripped you off. saying they replaced it with a new one. I had mine replaced and I felt a little more resistance for about 50 miles but then it "broke in" and was back to normal.

 

If the error codes refers to the tranny having shift problems on 1-2 gears, check the governor actuator switches. They may be bad or going to go bad. It is possilbe they may not replace these switches when they rebuilt/replaced your tranny.

First, you may want to check to see if you have ever replaced both the tranny speed and output sensors. These sensors failures are common on 1st Gen Durangos. It can give you that power loss problem when accelerating. These sensors can be flaky enough to cause problems without throwing a check engine light.

Lastly, but unlikely, it may be your TPS (throttle position sensor). But this sensor is another common sensor to go bad on the 1st gen Durango.

All 3 of these sensors are not expensive and you can buy them from your local parts store. TPS is a easy do it yourselver, but the tranny sensors may take a little more time as you have to go underneath your durango.

As your Durango has over 218k miles on it, if these sensors never got replaced, I would replace them anyways.

 

We did have the Throttle Position Sensor replaced at one point, because the Durango was accelerating by itself. I think that was probably at about 100k, so I will look into doing it again.

I don't know when the last time the car had a tune-up. It was my mom's soccer-mom-mobile before it was mine. She bought the car new in 2000, so she probably has record somewhere.

Thanks for the ideas though, I will look into these things because I don't think the speed sensors have ever been replaced. I will have a mechanic check out that transmission to see if it truly is new. Can you recommend a good shop to have check it out?

There is one Chrysler/Dodge dealership here, but I have already taken it to them and they can't figure it out. Is Aamco generally a reliable place? One just moved in to town. Maybe I should try there?

I will drive my Durango until it is dead! It runs like a dream for having such high mileage and I'm still getting about 18-20 hwy. I love the thing...I would hate to have to buy a new car.

 

Aamco is a good place. If the car hasn't had a tune up in quite a while that may be your problem. Spark plugs, wires, distributor cap and rotor, O2 sensors and such.

 

Have a fuel pressure test done to it. It might have something to do with the fuel pump.228K on any fuel pump is unbelievable.

Second, Did they install a new Torque Convertor????? Also the trans might need to be re-adjusted and I would definatly get a fluid and filter on the transmission.

Just by chance, a mechanic could have installed the wrong trans fluid and that would do it.

 

I have this exact same problem. I was wondering if this was or has been fixed or not. I'm about to go start a thread on my own. Thanks.

 

I haven't even had anyone be able to diagnose it, much less fix it. Good luck. I hope you figure it out so that you can spread the knowledge

 

You said it got better after an engine flush=is that the oil or the coolant-if it was coolant then maybe the truck is going into closed loop-or cold mode or if an oil flush it could be going into "limp home' mode due to low oil pressure=does your oil gauge show about 35 psi=just below 40 at idle.....and last but not least make sure to check the battery and charging system=if the alternator is putting out low voltage{13.9 or lower} it will play havoc with the comp or a bad battery will also caus the truck to turn over slowly...One last thing did they change the torque converter when they did the tranny?.............Aamco=around here ya better off with a junkyard transmission then goin to Aamco>>my opinions are personal and do not represent Dodge forum in anyway however=LOL

 

03-12-2009, 03:35 AM
macanddons7
Registered User
My Garage
Join Date: Mar 2009
Posts: 8

1781 code means your lock up torque converter is not working and will need tranny work done i just did.

This is what I was told. I'm going to go to a tranny shop since no one knows what this is. I'm gonna replace some things. There are 4 sensors on the out side of the tranny. I'm gonna change the fluid and filters. Supposedly there are like 3 or them. I'll let you know what happens.