p0741 2001 sport trac

[SteveV]

Hi guys. I have rebuilt my neighbors 5r55e, new central vb, 2 convertors (rockauto), internal harness and we are still getting light of death and p0741.

Borrowed snapon scanners lastnite and pcm commands lockup in 4th gear, of course it does not see the drop in turbine speed times out set the dtc and trans shifts like crap.

We are pretty much down to it is either the harness or the pcm itself. I am looking for a schematic so I can test the wires at the pcm.

He removed the trans last weekend and we where able to apply the convertor with air through the pump. I compared the new and old valvebodies, ohmed the tcc sol 15ohms IIRC, checked the new harness. Put in 2nd convertor and still the same issue.

Thanks for any help.

 

[swshawaii]

http://www.explorerforum.com/forums/showpost.php?p=3205683&postcount=2

http://www.bbbind.com/free_tsb.html

 

[SteveV]

update

So we checked the resistance at the plug and got 10.8 ohms. Then checked for power for TCC sol and got battery/alt voltage. Then we ohmed the wire from the tcc sol all the way back to the PCM and it ohmed less than 3 ohms. After that I backed that terminal out and ran the truck and grounded it. I could not see any drop in rpms on the tach. At that point I put my foot on the brake and locked the TCC in drive and it stalled the engine 3 times. I am guessing that the tach is not able to show that small of an rpm drop.

At this point I am thinking PCM is bad, possibley the driver itself. The pcm did pick up the open tcc circuit as the light of death was flashing steady the entire time.

I will add that the unit was pulled out a 2nd time and I can apply the tcc (hear it thump) when I apply air to the pump. I rigged it up so that the pump was in the convertor(blocks of wood holding convertor up) used the feed hole and whola. That proves convertor is good, seal on stator support is good as well.

New central valvebody and took the tcc valve train out of both old and new vb and everything looks fine. Ohmed old and new TCC sols and both are about 10-11 ohms.

Can here TCC sol click when it is applied in park as well as little spark when it is grounded.

The only thing I did not replace is the internal turbine speed sensor. Kind of wishing I did at this point. But no dtcs for that circuit as well.

So any opinions before we boom a PCM at it? I feel like we have ruled everything out at this point.

 

[SteveV]

anybody?