L322 2004 4.4 Trans Fail Safe fault code & locked in 4th gear fault

[knightrider]

hi guys I got the Trans fail safe warning message ping up today along with the car locking to 4th gear (can't change gears manually either). I managed to limp the car home and hooked my icarsoft scanner up which is throwing the following faults:

P0755 State: Plausability Fault. Shift Solenoid B
11 State: None. Shift solenoid 2 Fault

Does anyone have any idea on what the cause of this fault code is and how to go about fixing it, thanks in advance for any help

 

[Datatek]

hi guys I got the Trans fail safe warning message ping up today along with the car locking to 4th gear (can't change gears manually either). I managed to limp the car home and hooked my icarsoft scanner up which is throwing the following faults:

P0755 State: Plausability Fault. Shift Solenoid B
11 State: None. Shift solenoid 2 Fault

Does anyone have any idea on what the cause of this fault code is and how to go about fixing it, thanks in advance for any help

No idea, but I assume you have enough oil in the box?

 

[knightrider]

Datatek I had a look underneath the car and there isn't any transmission oil leaking so i think the oil level is ok.

I reset the fault code and tested the car, I was able to drive fine for about 10 miles before the error message came back. This time it was the same error code with a slightly different message as below:

P0755 State: Open Circuit
Shift Solenoid 'B'

It looks like there is a fault with shift solenoid, can anymore help me out with information on where to get the correct replacement shift solenoid and also what the procedure (and how difficult) is to replace it?

 

[holidaychicken]

I’ll reply here as well as FFRR !

Rave download

https://www.landyzone.co.uk/land-ro...lus-other-useful-info-on-range-rovers.322195/

Quality thread from your man @Saint.V8

https://www.landyzone.co.uk/land-rover/zf5hp24-fluid-drain-and-filter-change.212722/

JPAT for spares I think, @Bemble = RRPhil if you are googling
Sorry no time to add more detail but everything is on here, get rave also from download
I wouldn’t be changing anything without confirming your fault , there is an epic thread here

http://www.fullfatrr.com/forum/post351030.html

from my reply on your other thread
I have replied to your other thread as well, JPAT for spares but I would send Phil a message as he will definitely be able to advise you better than me and he may also have the spares you need on the shelf

https://www.jpat.co.uk/uploads/1/0/3/5/103..._5hp24.pdf

This is the correct fluid
https://www.ebay.co.uk/itm/Mobil-ATF-LT-71...1244234762

Filter needs to be Filtrans genuine ideally
https://www.island-4x4.co.uk/gearbox-filte...26665.html

 

[knightrider]

Cheers mate top man for your help!

 

[holidaychicken]

Phil has replied to your other thread, you are now in very good hands, post back your solution here though as well.

 

[knightrider]

Hi guys I had the soleniod replaced yesterday and it has fixed the problem, I've done approx 100 miles since and had no further Trans fail messages.

Whilst changing the soleniod I also had the gearbox filter and oil changed along with replacing the oil cooler as I have had the gearbox go into the cooling strategy a few times this summer. I've had the car nearly 5 years and for the last few years I had the classic torque converter LUC rumble/vibration at 30mph and 50mph. It had gotten worse over the last year and I had been using the gearbox in manual mode as it largely eliminated the noise. I'm pleased to say the noise/vibration is now hardly there (95% improvement) so for anyone with similar symptoms maybe try a oil change before replacing the torque converter.

The gearbox oil in my car was changed between 50-70k miles ago from the service records and the fluid that came out was dark and similar to cola colour. There was no sludge, metallic flakes or burnt smell etc and the magnets were pretty clean which was good news considering its gone to cooling strategy at least 6-8 times since I have had the car plus had the torque converter rumble for many years.

Due to the previous overheating I decided to have the oil cooler replaced at the same time, since doing so I've found the gearbox oil temperature is sitting at around 100 degrees Celsius whereas before it would go up over 110 -120 Celsius with normal driving so it's definitely keeping things cooler. I had the radiator replaced with a Hella unit earlier this year.

The car is driving nice and smooth now, my only concern is there is a possible gearbox oil leak from one of the oil cooler connections but I'm not certain yet and will monitor it over the coming days.

I would like to give a MASSIVE thank you to RRPhil for his invaluable advice and knowledge and for kindly sending me a replacement soleniod. Big thanks to holiday chicken too for his help.

 

[holidaychicken]

Good news, if you have some spare cash it is worth carrying out another oil change later on as the TC holds a fair amount so unless you remove the complete transmission and TC you can't change it all.
I changed my transmission pipes, stat and cooler under the guidance of the legend that is @Bemble (RRPhil) when I rebuilt my transmission and had the TC refurbished - the man is a true gentleman and an amazing engineer.