I have a 2004 L322 TD6 with the GM 5L40-E gearbox with 116,000 km and fully serviced.
Last week I decided to change the ATF fluid, filter and gasket, and drained sump and replaced filter with genuine LR THE50031 Filtran filter. Filled the transmission using Texamatic 7045E ATF strictly following RAVE procedure and using GAP IID tool to set fluid level at correct gearbox temp. Then also replaced Transfer box oil using recommended Castrol BOT 26 FMB1 Transfer Box oil and filled same using LR procedure.
I then went out to road test vehicle and drove approx. 400m down the road and initially all working fine. Stopped vehicle and set to Low Ratio, all appeared ok, then with vehicle stopped and in Neutral selected back to High Ratio and went to Drive on gear selector and initially it appeared that the vehicle was stuck in LOW ratio, after some switching off and on ignition and toggling High a few times, vehicle drove as if in High, however shortly afterwards I received Trans. Failsafe Prog and car went into limp home mode (5th gear). I drove vehicle back home and using GAP IID tool diagnosed the following faults:-
Transfer Box
1/2 (0x5212) Battery Under Voltage
2//2 (0x5223) Signal Noise in Acctuator

Transmission
TCM Transmission - Pressure Line Solenoid 4 : General Fault.
I am currently awaiting clarification from GAP as to which Solenoid this is.

I then cleared the faults using GAP tool and fully charged up battery for 24 hrs.
I have test driven the vehicle a few times since, and all works ok in 1st to 3rd gears in manual mode and I am able to drive several km without issue, however if I go upto 4th gear in manual mode, the Failsafe Prog. Limp home initiates immediately. In automatic Drive mode I am able to get approx 800m (4th gear) before the Trans. failsafe Prog appears. If I turn ignition off then on, the vehicle returns to normal operational mode and gearbox functions in all 5 speed gears, until the dreaded failsafe returns after about the same distance driven. I am assuming that this rules out temperature?, so more likely a Control or command related fault?. (Actual gearbox temp around 54 Deg C, with max gearbox temp recorded at 88 Deg C).
Is it merely coincidence that all of this has happened immediately after new transmission oil change?, or more likely a transfer box systematic Fault such as a faulty transfer box stepper motor potentiometer?, or could my gearbox have suddenly junked when new higher viscosity fluid introduced?. Note no metal filings observed in sump when drained and cleaned.
I have reviewed several blogs indicating Trans. Failsafe Prog can be caused by Faulty Stepper Motor, Gearbox Faulty Neutral Sensor Switch, Faulty ECU or possibly blown seals, sensors solenoids etc. Within gearbox.
I am in Norway which is the most expensive place on the Planet with respect to LR parts and labour, therefore not to keen on going through the high cost of process of elimination.
Has anyone suffered exact or similar Fault?
Further to above when test driving and connected to GAP IID tool live values on Transfer Box, Range, The GAP tool displays Low - Stop, however vehicle is in High.
I came across this comprehensive Trans. Failsafe Prog diagnosis article which eventually pointed to the Stepper Motor potentiometer requiring replacement. http://www.valvebodypros.com/assets/range-...roblem.pdf
I have also found a supplier in UK called LRO4x4 which claim to fully refurbish the Stepper Motor and replace the potentiometer with a more robust Potentiometer for 385 pounds, has anyone any experience with this company?. They supposedly provide a 12 Month warranty for the refurbished Stepper Motor.
http://4x4lro.co.uk/home
Finally when reviewing many threads on GM 5L40E and Failsafe modes it would appear that these gearboxes are prone to failure, however mine has only accumulated 116,000 km (72,000 miles) and has not been used for excessive towing or anything, so this would appear a little premature. Also gearbox was working perfectly prior to filter and oil change and selecting Low Ratio, which makes this a little weird?
Anyone have any suggestions or advice?. Should I try to fix or simply trash the gearbox and go for a remanufactired replacement transmission?. [/b]

Last edited by jms001 on 24th Apr 2018 8:32am. Edited 1 time in total

Hi jms001

Ok I can help you here, as I am familiar with the faults you experience:

1. TFC as you have the NV225 TFC (same as mine) the faults are:

a) "Battery under voltage" - the L322 Td6 does not like a marginally charged battery.
b) "Signal Noise in Actuator" Your potentiometer in the TFC stepper motor is fubar. You will have to buy a new motor.

TFC motors are available from LRdirect at ca. �600.00. Ignoring this "noise issue" will eventually put the gearbox in permanent limp mode.

2. Actuator4 issue points to burnt direct clutch linings or sticking valves in the VB.

In your case having done the gearbox flush has produced to opposite result of what you anticipated.

You will need to:

1. Strip the valve body down
2. Fit the Sonnax mods to the valve body

https://www.sonnax.com/parts/4120-remanufactured-valve-body NB: Exchange units are no longer available but there are places in UK who will do the Sonnax mods such as RRphil

3. Thoroughly clean out the gearbox cooler and the cooler pipes. If in any doubt as to the effectiveness of the cleaning process, replace the cooler.

4. Refill the box with Texaco 7045E as before. If you cannot get that one, use Fuchs IIIG as alternative.
5. If box is operating now fine, then you are ok.
6. If not then a complete gearbox tear down is called for. There you will need to have the pump housing modified with the Sonnax kits.

This should then render your box operative again. (These Sonnax mods are mandatory unless you want to do the box again in around 15-20000 miles from now).

Remember without the Sonnax mods you are wasting your time!!! (Got the t-shirt on that one).

Good luck

George

Last edited by hgbosch on 30th Nov 2017 11:27pm. Edited 1 time in total

Hi George,

Sorry been out of the loop for a few weeks stuck out in the middle of the North Sea. So I have not got any further with my Gerabox issues.
As for the voltage and noise issues, I fully recharged battery and cleared the Fault codes and thus all appears ok on the Transfer Box side.
The auto transmission is another matter. The gearbox still functions very smoothly in the first 3 gears and reverse. The main problems occurr shortly after moving up into 4th gear and either up into 5th or back down to 3rd, whereby the Transfailsafe mode kicks in immediately. If I pull over and switch off ignition, the TFM disappears and I drive home carefully using gears 1 to 3 without problem.
I was contemplating replacing the 4th to 5th shift Solenoid and possibly the TCC and the Pressure Control solenoids, as well as opting to replace the Stepper Motor.
If you have a contact email address for RRPhil let me know?, as I will try to contact him to try and obtain a refurbished valve block complete with Sonnax upgrade.
Cheers
Jon

Hi Jon

your issues with the gearbox are the direct clutches starting to give. If you have a Hawkeye, GAP or similar tool, you can check that up for yourself by putting the diagnostic in Live Data mode and then monitoring actuator4 behaviour. You will see that it will increase (in my case to over 90%) and ultimately going into failsafe mode. This is as a result of a mismatch in rotational speeds due to a slipping direct clutch.

You will have to strip down the box and send the pump housing and the valve body to have the modifications done. Sonnax agents in Norway are:

http://www.sarpsborgmotor.no/main.aspx?guest=yes

Alternatively you can send the whole box to them and ask them to overhaul the box and incorporate all the Sonnax mods.

My L322 is currently in the gearbox shop for an overhaul incl. all the Sonnax mods.

The noisy potentiometer in the TFC stepper motor will show again. It initially starts intermittent and will get worse over time.

I have attached files showing the mods

Hi George,

Firstly, I did not receive the attachments that you refer to in your previous reply. I have also sent an email to the email contact address, you have provided for more info.
Yes I do have a GAP IID BT tool, but please can you provide some more detail on what Live values I should actually be looking for, with respect to actuator 4 as you mention above?.
The exact fault code that is displayed on my vehicle using GAP IID tool is:-
TCM Transmission - 0x4 Pressure Line Solenoid 4 - General Fault
I have contacted GAP for further clarification, however they are not able to provide me with any more information on what this Fault Code is.
The shift solenoids are labelled A,B,C and the other two solenoids are simply referred too as TCC (Torque Convertor/Clutch) Solenoid and Pressure Control Solenoid. (There is no Solenoid 4). There are also the spool valves located internally on the valve block and 4 x Clutch shift accumulators which I have learned can fail due to broken spring, although this should not explain why it registers as a Fault Code with Solenoid 4. Perhaps I need to take to Land Rover and get them to provide a diagnosis using the T4 code book?.

I have been through all of the live values on the IID tool, but am not aware of any that display actuator or Solenoid values?.
I am specifically interested to hear why you are so certain that the clutches are burned?, as gearbox was functioning perfectly immediately prior to oil/filter change, so still at a loss to explain why replacing old oil with new should cause clutches to fail?.
The gearbox has only done approx. 72,000 miles from new and no hard off-road driving.
Cheers
Jon

hgbosch what range rover do you have ? I think rrphil only specialises on the non gm transmissions

Hi Bertie

I have the 2003 Td6 with the BMW inline 3lt Diesel. As Jon lives in Norway, I have sent him the details of the local Sonnax agent who will be able to sort that box out.

My vehicle is currently with the auto trans rebuilders, to have the SONNAX mods done on the valve body. The pump housing had the Sonnax mods done recently. All the friction clutches in the box will now be changed again.

kind regards


George

Hi jms001

Did you do the Sonnax mods on the valve body. These are critical on the GM box if you want your gearbox to last. I have previously sent you the details of the Norwegian Sonnax Agents.

Regarding the faults on the transmission "failsafe mode etc".

Once you have disconnected the TFC stepper motor harness (with or without replacing the motor) you will have to clear the TFC errors. For this you need Faultmate MSV2 or the RSW Solutions cable with the software. Or naturally the JLR diagnostic system (expensive).

Hawkeye does not recognise the NV225 TFC.

Hope you come right.

George

Hi George,

I did enquire at the pricing to undertake the Sonnax upgrade in Norway! However I could buy a replacement geArbox from UK, for less than the quotation for the upgrade. So no I did not venture down that route.
My gearbox has now accumulated 116k km or 72k miles so is now entering into the unknown GM5L-40E reliability territory.
But as it is running very smoothly and no signs of any metal particals in the sump or on the magnet when carrying out ATF oil changes, I am willing to risk leaving it as it is for the time being.
As for the Stepper Motor I have a GAP IID blue tooth diagnostic tool that does all of what the RSW tool does and more. So no problems clearing codes etc. As posted in my reply, the Stepper Motor change out was literally a 5 min job and all works fine.
Also my original Stepper Motor tested out fine and was still well within the variable resistance load values as described in the test procedure when I powered it up using 12v power supply.

Cheers

Jon