Code P0741 and new transmission 02 4.6is

[smwmustang]

I am getting the code P0741. I had it reset but it came back on today as I was not sure if it was just an error. I have a new transmission that has about 12,000 miles on it as well as a new transfer case and drive shaft with only about 3,000 miles on it.

Any idea if the TC would have been changed out at well as part of this repair. I bought it this way and since the parts were still newer and under warranty I felt good about buying the X.

I would also assume that it would not be low on transmission fluid or have a bad solenoid since it is all new.

Any help....and should the dealer be able to tell me if the TC was replaced?

Thanks,

Shawn

[RRPhil]

Renewing and getting the right preload on the lock-up clutch on the 5HP24 torque converter is a specialist job because it’s a friction welded assembly.

http://www.xoutpost.com/863854-post40.html

Even if the TC was replaced with the transmission it’s possible that the LUC in it hadn’t been touched.

If you cruise along at 60-70mph and quickly remove your foot from the accelerator do the engine revs stay the same or does the engine speed suddenly drop?

Phil

[smwmustang]

I will have to give this a try and see what happens this afternoon. Thanks for the info and for whatever reason the SES light went out today. I have read where it can come on intermittantly for no reason and has never caused any problems.

A test on the interstate will let me know more based on your info. By the way, should the revs suddenly drop or should they stay up? I know quite a bit about cars but not transmissions and converters.

Thanks,

Shawn

[RRPhil]

The lock-up clutch should be fully locked in this steady-state condition so the engine speed shouldn't change when you take your foot of the accelerator.

At lower (constant) speeds the LUC will be in its 'continuous slip' mode and the engine revs should drop immediately you take your foot off the throttle.

Phil

[smwmustang]

Ok, I tested it yesterday at about 70 MPH on the interstate 3 or 4 different times. Everytime the RPM's stayed up where they were and only dropped maybe a 100 RPM's. It was around 2500 RPM's and it pretty much held that everytime.

Maybe the code was just an error or it corrected itself....will wait and see. No other issues as far as driveability or gas mileage.

Thanks,

Shawn

[ArtMan]

Well smwmustang....

I have the same issue. I just rebuilt my transmisison. I have the 3.0 so i have the gm 5l40e tranny. I also ordered a re-manufactured torque converter. Now when i get on the freeway i get that same code as you P0741 or bmw code 48. I did the same test as RRPhil had said which was at 60-70mph when i lift my foot off my rpms drop to 1200-1500. Now the question i have Phill can it be the tcc solenoid? Should i drop the pan and check it before removing the tranny again for the torque converter? I bought my torque converter from Torque Converters - Precision of New Hampton. any thoughts?

[ArtMan]

Also one more question Phil,

When i got the reman torque converter, when i looked inside there was a part that moved around up and down and side to side. Looking at your thread where you cut one open from the range rover which has the 5l40e tranny i cant see anything that should be moving around?

[smwmustang]

So far no more issues with mine...however....I have not used the Sport or Manual mode again. I only got the SES after using one of these modes....or at least it appeared that way.

[RRPhil]

@ArtMan

Compared with the ZF torque converter the GM unit is very straightforward to remanufacture so I think you should assume, for now, that your replacement unit is functioning correctly in response to the hydraulic pressures it’s being fed. The stator has an amount of free play (both axial & radial) so I think we should also assume that’s the internal movement you noticed.

The reason the 5L40-E torque converter lockup clutches fail in the first place is that wear in the valve block allows the spool valves to leak and therefore the hydraulic pressures drop off allowing the LUC to slip. If you’ve simply replaced the TC you may have fixed the symptom but not the cause. Did you fit a replacement valve block or have your existing one checked during your rebuild?

It would certainly make sense to check the TCC/PWM solenoid valve – particularly to see if the screen is damaged or blocked in some way.





Another cause could be the TCC control & enable valves which are mounted in the oil pump cover



but clearly it won’t be possible to check them now the transmission is back in the vehicle.

I think you’re right, therefore, to concentrate your efforts on the TCC/PWM solenoid valve first.

Phil

[ArtMan]

Thanks Phil,


Well, no i did not have the valve body checked out. When i did some research i figured most ppl who had same tranny had no reverse or delayed responses and i had not of that. the master rebuild kit i bought came with new valve body gasket and all the orings for he valves and solenoids. but the company (started with S) that remanufactures the valve body i think only does the valve body and not the valve in the pump. I will be crossing my fingers and hoping that my issues arises from the TCC solenoid.

Worst case ill remove tranny from the car yet again...ill update tomorrow about how it goes.

PS: will i be doing damage if i drive the car like this with speeds up to 60mph only?