Trans code P0741 more questions, but learning

[malcolm2]

01 mountaineer, V8 AWD. 264K miles. I believe it is the 4R70W tranz. The OD off light started blinking. Goodyear read the codes. P0741 and P1728. I have been studying up on 741. One post I read said to note the vehicles actions. At first I noticed no real change. However, it was mentioned to pay close attention to the shifts. Basically, do the RPMs drop slightly at a shift? So, the only one that does not is the last gear. Tuff to tell if it is 4 or 5. I always thought this car had 4.

That being said, another post mentioned that fluid and filter changing could help. also that all the solenoids come on valve body. If the sol has broken up, new fluid would be in order and of course a new sol. And the complete VB would be around $200. Does it seem I am heading in the right direction here, at least on this code? If code 2 is the death code, I will stop here. But if not, I figured dropping another $200 plus fluid and filter is not the end of the world.

Cause Good Year can only recommend complete replacement for $3500.

Comments welcome.

 

[JK080]

Those codes indicate that there is a problem with the torque converter clutch, either its not being applied or it is slipping. The best way to test this is with a scanner that can read the transmission data, you should be able to watch for converter apply and monitor slip. Anything with the converter clutch circuit could be to blame, the best scenario would be with a bad TCC solenoid, you could drop the pan and replace it pretty quick. Other possibilities would be a stuck valve in the valve body or a pump and converter problems.

I would pull the pan and if there is signs of excessive debris I would know it's better to rebuild the transmission, if the pan is clean I would test or replace the TCC solenoid. If the solenoid tests good I would drop the valve body and have a look around for stuck valves or something causing issues before pulling the transmission for further inspection.

 

[malcolm2]

Thanks for your reply. I forgot to mention that the Good Year guy turned the Blinking OD off lite OFF. At least I assume he did, cause it was off after he checked the codes. I drove the car this weekend, even pulled the boat to the lake and the blinking remained off. Maybe 75 miles.

My plan is to do as you suggested, but I believe I can wait 'til I have some time. I may rush it up if the blinking starts again. The fluid, filter and gasket were changed 2 years ago. I checked the fluid this weekend and it is still nice and clear-ish pink.

I know this is Tranny talk, but how does the tach get it's rpm signal? over the last year, I noticed that the tach jumps around sometimes on the interstate. no change in revs, just the needle... UP then DOWN then normal. And while paying attention to the shifting, the needled jumped to 4000 and just stayed there for several miles regardless of speed. It would drop 500 revs during most shifts, but remain high. Is that tranny related at all?

 

[malcolm2]

BUMP>>>> so what are your thoughts on the "OD off" blinking light staying off? I have been about 400 miles. Working on my 2nd tank of gas since the dude cleared the code. Pulled the boat to the lake 2 times, getting about the same MPG.

 

[JK080]

Well if you have gone that amount of distance I would wait on any attempts or a repair and see if it returns. Starting to sound more like a bad solenoid rather than a bad converter or other problems.

The tach I believe on that vehicle will get its info from the computer that is reading the crank sensor.

I would have to experience the issue with the fluctuation of the tach to be able to determine if its normal or not. The converter engagement (TCC) may drop the RPM's from three to five hundred RPM's when it comes on, mostly noticed at higher speeds.

 

[malcolm2]

Well if you have gone that amount of distance I would wait on any attempts or a repair and see if it returns. Starting to sound more like a bad solenoid rather than a bad converter or other problems.

The tach I believe on that vehicle will get its info from the computer that is reading the crank sensor.

I would have to experience the issue with the fluctuation of the tach to be able to determine if its normal or not. The converter engagement (TCC) may drop the RPM's from three to five hundred RPM's when it comes on, mostly noticed at higher speeds.

Thanks for chiming in. I will do some additional studying along with paying closer attention to the shift points and MPG.

I will start another thread on my tach issue. It is not a drivability problem, but sounds like it could and maybe already should have given me a CEL code if it is a crank sensor. That should be an easy replacement.

I may not have mentioned this and maybe it is why the OD light blinked in the 1st place: When I saw the blinking light, i checked the shifter. It was kinda between D and 2. I have been paying more attention to that too.