04.5 48RE torque converter lockup feed wires

[JCBerry]

Does anybody know what wire or wires feed the transmission to get torque converter lockup?? My truck still only has intermittent lockup and I think its electrical. Picked up truck Friday after a new converter & pump, trans tried to lockup once but hasn't since in 300 miles. Would like to show dealer & rep I'm not crazy about the vibration i get when it does lockup. Would like to also be able to prove converter is not locking as the rep thought it was although the two trucks we drove didn't have the same rpm at the same speed 400 RPM higher on mine and 5 MPG less. The rep said that wasn't significant. :-{} Guess he hasn't looked at fuel prices.

Please help.



04. 5 5. 9ho QC, 3500 4X4, DRW, LSD, Laramie Oo. 48RE :{

 

[ThomasLawrence]

Does anybody know what wire or wires feed the transmission to get torque converter lockup??

It's the orange/black wire on the 8-pin connector. See this picture. Grounding this wire will engage the lock-up clutch.



Now, that said, I don't know if I would go around hacking up the wiring to demonstrate something to the dealer. There's a couple of simpler ways to see if the TC is locked. First, at crusing speed (>50MPH), apply some additional throttle - not enough to cause a downshift, but enough to accelerate the vehicle. If the TCC isn't locked, RPMs will climb immediately, with little to no change in vehicle speed. If the TCC is locked, the truck will accelerate, with very little change in RPM.



Secondly, if the TCC is locked, maintain constant throttle pressure to hold 55-60MPH, then tap the brake with your left foot. This will cause the TCC to unlock, and RPM's should immediately jump up, without a change in speed.



-Tom

 

[JBlock]

DTT has an electronic filter that might address the problem.



Gooc Luck.

 

[Dieselnerd]

Thomas Lawrence gave you good advice. Try it, if it doesn't work like Thomas said, take it to the dealer and MAKE THEM FIX IT! It's their job as long as you have warranty coverage. Don't cut your wires, that will only give them an excuse to say you caused the problem.

 

[JCBerry]

Thomas

Thanks for the info.

I wasn't going to cut any wires just check for grounding & if none piggyback with a needle beside the electrical connector pinto gnd at 60MPH.

The truck has been in 4 times in the past 3K miles for the same problem, and 23 days out of service. The converter is not locking and they don't see it, I don't think they've had a mechanic drive it just the service writer and rep, the rep had never driven a 1 ton or a diesel and the writer owned a 5 speed.

I've been a mechanic for 25 years and have told them specifically what the problem was but with no code they play stupid, on the ride with the rep we drove mine and an 05 and the 05 locked up, 17. 5 MPG with 25 miles on it, mine 9K miles 12 MPG, light throttle increases rpm 400, let off RPM drop almost 1000. Thanks for the info the check engine light came back on again today so tomorrow I'm calling a lemon law attorney. Enough is enough I've had it.

Found loose bolts on trans when I checked what they had done, not even finger tight. :--)

 

[ThomasLawrence]

Found loose bolts on trans when I checked what they had done, not even finger tight.

Idiots... I hate to hear stories like this. 10:1 it's something extremely simple - like a dirty APPS, or a flakey brake switch. It would take a competent mechanic less than 30 minutes to fix - but because nobody has a clue, it's going to turn into a legal battle.



Before throwing in the towel, why not try a different dealership?



-Tom

 

[JCBerry]

Thomas

just checked connector no orange/black

From the picture it looks like pin 7 is that correct?

I'm not sure if at this point I want to continue with the Auto when they can't diagnose a simple problem like this. If I get a stick at least it's not in gear because I didn't put it in. I'm towing a 38' travel trailer too so maybe I'd be better off with the stick.

Thanks again

 

[ThomasLawrence]

From the picture it looks like pin 7 is that correct?

Yes - pin 7. Guess they changed colors (again). Another practice that makes little to no sense...

 

[JCBerry]

Thanks

Still no lockup

Guess all the real mechanics have moved on due to low pay,

Thats why I stopped working on cars for a living.

I appreciate the help.

Jay