I am chasing a very frustrating transmission slipping issue and p0741 tcc fault code for over 6 months.

2005 LR3 4.4L with 205,000 miles.

I’ve already flushed the fluid, replaced the pan and filter, replaced the tcc solenoid valve in the trans valve body, and replaced the torque converter itself. The problem remains completely unchanged.

The fault code comes on consistently once I reach above 50 mph and the transmission will slip trying to start from a stop and travel up an incline slowly.

And I can’t tow my 5,000 lb boat at all because it will basically just rev and slip and won’t move forward with the added weight.

the car drives pretty normally when not towing and shifts, stops, and goes with little abnormal function..

It’s frustraing that none of my fixes made the behavior change one bit. It’s exaclty the same as before. No other fault codes are or have been present.

With the major potential mechanical issues fixed or replaced, in starting to think its an electrical or software issue..

Has anyone else delt with this trans issue or have any suggestions on how to test the trans electrical or software systems?

 

I looked back into your post history about this issue. Man, sounds frustrating as all hell! Sorry to hear of your troubles.

Back early on you mentioned it might be a speed sensor... but I don't see that in the list of things assessed or replaced.

Now, I'm no LR expert but I have fixed a transmission stuck in limp mode from a bad VSS on a 7.3L F-350. It didn't cause the symptoms you're explaining, but that F-350 certainly wasn't the LR3's complicated computer either.

Anyway, I would start here. At this point, you've addressed and thrown a lot of time/money into the big items that would logically cause this fault. Assess the speed sensor with an ohm meter and make sure it falls within spec output. However, since this is triggered precisely at 70 MPH (based on a previous post), it may not show. Considering a VSS is usually a cheap part, you could also just swap it out. The troubling thing, is that you could also have a short somewhere in the wires up to the ECU that a new VSS won't fix.

 

Just had a thought and came back to share it with you. Perhaps it is the computer itself. In medicine (which is a hell of a lot like auto mechanics) this is like a diagnosis of exclusion, going through this and that to rule out every other differential (unfortunately you've been paying for the transplants) but at some point... It comes down to either circuitry, processing, or the organ itself (your tranny?).

If you have a friend with an LR diagnostic tool, or can find/make on nearby on this forum, seek help. I don't have one myself, but I have a friend who does, and that can decode a lot of the "codes" you get from OBDII scanners. If you're in the ballpark of Willamette Valley Oregon, I might be able to help.