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?

Thank you!

Phil

 

I would get the software updated on it from the dealer... sorry to hear the "normal" fixes didn't help.

 

I have similar symptoms on my 2005 with 154k miles but without the towing load. It usually runs OK for a few mins after cold start, then intermittently starts to slip. Gear shifts may be fine or may be very jerky. Once in every 2-3 journeys I will get complete slippage for 5 seconds when pulling out of an intersection.

I get fault code p0741 and also some codes for incorrect gear ratio, and occasionally the F on the dashboard for the gear indicator gauge.

How easy is it to replace the solenoid or solenoids? I have done a couple of LR3 transmission filter changes on other cars in the past (I always updated to the BMW transmission pan for easy removal).

 

Swapping the solonoids with the metal bmw pan is quite easy but to be honest In my case, I didn’t want to risk it being seals or clutches or the valve body so I bought a 76k Mile used transmission off eBay for $1,200 and swapped the whole thing in there.

Filled her up with fluid and she’s run perfect for 6,000 miles so far.

I plan on rebuilding the old one at some point and selling it, which will make most of the money back.

hope this helps!

- Phil

 

How tough is it to replace the transmission and how long did it take you? I would like to give the solenoid replacement a go before replacing the whole transmission, as it looks like they are under $100 and seem to be a lot easier to swap out than the whole trans, as I only have access to axle stands, no lift.

I have pulled manual transmissions out of Porsche 911's before, but never removed an auto box or a Land Rover transmission. I would consider myself to be a competent home mechanic with a fully loaded pro mechanic tool chest.

 

We fortunately had access to a lift and a transmission jack. Obviously a lot easier than on stands. Biggest pain in the *** is unbolting the transfer case and lowering it because it’s unbalanced and awkward.

Once that is off the transmission is pretty straight forward except clearing the front cross member takes the perfect angle and a trans jack is REQUIRED. You have to put it at a severe angle to get it out.

Re install is straight forward but as hard as the transfer case bolt access was on removal, rebolting it up is 3x as hard. There’s Just no access to the top bolts on the transfers case.

i honestly wouldn’t attempt it on jack stands unless you could get it up at least 3ft off the ground and had 4 strong friends to support the trans on removal.

A local shop quoted $1,500 for labor to do the swap and if you can get close to that, I’d consider that option as well.

 

OK, I've pulled the mechatronic unit from the transmission, replaced the 7 solenoids and am trying to refit it. I am struggling with engaging the new wiring harness sleeve to the electrical connector's locking tab on the mechatronic - it won't close. It seems a metal spring plate stops it closing.
Any advice on how to reinstall this part?

 

For those wondering, I found the answer on Youtube:


The car is back together and drives very well, all the juddering, slipping and jerky shifts are gone. No codes popping up for the transmission. It took maybe 7 hours of slow, steady work with a bit of googling and learning as I went. Probably take 4-5 hours if I had to do it again. The old fluid was terrible, very dirty and smelly.

I replaced the following:

Transmission pan upgraded to Britpart metal unit with separate filter $125
Replaced all 7 solenoids (1068 298 044 01) $300
Flushed all the old fluid and put in new 6HP fluid ($200)
Replaced the Mechatronic Seal Adapter (0501 219 952 01) $17
Replaced the Sealing sleeve (0501 216 272 01) $17
Added 1 bottle of Lucas Transmission slip prevention fluid $10

I also cleared the transmission adaptations using my scan tool.

For the first time since I owned the car, I was able to drive it with no check engine lights, warning lights or codes getting thrown for engine and transmission. I may even be able to get it through smog tomorrow!

 

thank you for the update. I have a project LR3 that slips in 1st and 2nd and comes up with the trans fault code. I bought it like this. It was 3.5 quarts low on fluid!
I added it to the proper fill point and it’s a little better. But now I’m going to drain and fill next. And then if that doesn’t do it, I might drop the $400 on parts to service the solenoids. Or I might just sell it as a project at a loss