P0741 - Do I have the diagnostic steps corrrect?

[Doug Fraser]

This is a great site - Thank You. I recently solved a 2/3 shift flare problem using the info posted here.

I now have another trany problem.

I am getting a P0741 code.

When this happens my 99 Eddie Bauer with 5R55E will not shift into OD. This happens intermittently (about once a week or twice on a 250 mile trip).

Code: P0741
Trany: 4R55E
Vehicle: 99 Eddie Bauer
Fluid: Amsoil Synthetic ATF
Valve Body: Replace about 10 months ago - 15K miles (purchased from Central VB)
Cooler: Factory installed external cooler
Mileage: 230 Km => 143k miles
Other: No towing or heavy loads - 10 miles to work.

About 10 months ago I had a new valve body from Central VB installed. This corrected the 2/3 shift flare problem. All new fluid Amsoil ATF was put in and the the filter was changed.

About a month ago I got the flashing OD light. The code is P0741. When the code is thrown the trany will not shift into over drive. I stop the vehicle, turn it off then restart and then proceed. The vehicle will then shift correctly into OD. This scenario repeats about one a week or twice on a 250 mile trip. There are no other shift issues.

I have put on about 20k miles since the VB, fluid and filter was replaced.

I have done a search and read through the threads. From what I can determine, the following are the recommendations to address the problem.

1 Replace fluid
2 check/replace TC solenoid - high usage part as it modulates the fluid flow
3 check/replace EPC solenoid
4 re sleave the TC valve bore - or replace VB
5 replace VB - done about 20 k miles ago
6 could be a wiring harness problem
7 replace TC - low probability of being the problem

Since the fluid is quite new and looks good (nice and red, no burnt smell), I suspect this is not the problem.

Here is my question:

Does a rebuilt VB usually have a TC solenoid or EPC solinoid replaced or are they just tested?

Given the situation as outlined, would the first step be to replace the TC solenoid and EPC solenoid and fluid change?

Is there any way for a good shop to test the solenoids? Since the problem is intermittent I suspect they could test OK one time and fail another.

Any other suggestions or steps I should follow?

Thanks
Doug

 

[BrooklynBay]

I think you should contact Central Valve Bodies before you replace any valve body related parts. There might be a warranty. Here's some Information: http://www.explorerforum.com/forums/showpost.php?p=1724378&postcount=2

 

[Doug Fraser]

Thanks BrooklynBay - I'll give Central a call and see what they have to say.

I really don't think it is the TC as all of the other shifts are OK and the problem is only with the OD shift every once and a while. Of course the Ford dealership is recommending a rebuilt.

Doug

 

[BrooklynBay]

The dealer, and any other repair shop would usually recommend getting an entirely rebuilt transmission instead of diagnosing the actual problem. Let us know what Central Valve Bodies tells you.

 

[Doug Fraser]

I spoke with Donny at Central VB'S

The net was since the VB is less than a year old he thought that that it may be the Torque Converter.

He mentioned they test all the solenoids. In about 75% of the rebuilds they replace the EPC. In my case I had asked for a rebuild with the replaced EPC. They also resleave as necessary. The other possible culprit could be the converter clutch apply solenoid (I hope I got that right).

If it is not the TC then the rebuild has a one year warranty that he would honor.

Since the X is at the dealership now (getting the timing chain cassettes replaced - another long story) and will have the motor out, I am getting the TC replaced.

Will let you know what happens.

Thanks
Doug

 

[BrooklynBay]

The EPC & TCC solenoids are modulated, so they are considered high wear parts. These parts contribute to wear in the VB since they are always controlling the fluid path in a pulsating action with PWM (pulse width modulation). The area of the valve body gasket where the EPC is located is sometimes the first area to blow out since the low frequency pulses cause the VB bolts to get loose. It's a good idea the check for gasket fragments, and loose VB bolts whenever you replace the filter during a fluid change.

 

[Doug Fraser]

Got the x back tonight with a new (not rebuilt) TC installed. This was done by the dealer.

Short drive home and so far no problems. I will drive it for a while and then provide an update.

The reason it was at the dealer was because the timing chain tensioner(s) broke and the motor sounded like a diesel. Not real impressed that they had to be replaced. 20 hours of labour (they pulled the engine). That provided the opportunity to change the TC.

The tensioning cassetts were already replaced (about 6 years ago) under TSB/warranty that addressed the pining like noise the engine came with when it was new.

Doug

 

[Doug Fraser]

After about a week of driving the problem has not returned. The new TC seems to have done the trick.

The timing chain cassette issue is another story.

After having the dealer remove the engine and 20 hours of labour there is a chain rattle coming from the the driver side front of engine. All of the cassettes, tighteners where replaced. Both front and back. One of chains was replaced. This was a fairly major overhaul of the timing chain system including chains between the crank and jack shaft etc.

Goes back to the dealer on Wed.

Will let you know what happens.

Regards,
Doug

 

[Doug Fraser]

I was traveling on business and my wife took the X in to the dealer to have the ticking noise addressed. The service manager jumps in and test drives. He immediately says it is the serpentine belt. They put on a new one. The ticking noise is gone.

I found this hard to believe as the sound was ticking - no squeal. It really sounded like the dreaded timing chain rattle.

I did a search on the forums for noise from belt and found this thread.

http://www.explorerforum.com/forums/showthread.php?t=203852&highlight=Serpentine+belt+noise

It looks like the belt can cause a ticking noise.

All is good for now.

Regards,
Doug