Bought this in 2014 with 128,000 miles and had ‘hum’ and ‘cattle grid rumble’ almost immediately so got garage that sold it to do gearbox oil and filter change. Unfortunately they used a ‘specialist’ who put Dexron 3 in and made matters worse. After many arguments I bought the correct Mobil LT71141 (20 lt) and got my own garage to change.
For nearly 5 years and a further 30,000 miles it has been fine until recently. Trans failsafe from cold when trying to change in to 2nd gear, thuds in to 4th. After a short distance, stop, restart engine and it clears and all ok. Bought a new battery thinking that was problem but after 1 week same problem again! Checked fluid level and all seems ok (maybe a little high - unless temp too high when checking as poured out 😬).
I know this has been covered many times but most seem to have the problem when ‘hot’ not cold. At 157,000 miles not sure really if it’s worth spending a lot on, plus trying to find a decent ‘specialist garage’ that actually knows what they’re doing seems almost impossible. Can do a lot of jobs myself but I’m afraid no facilities to drop gearbox etc.
Any suggestions greatly appreciated, especially possible cause and cure.

Thanks in advance

Lenb Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

Issues when the fluid is hot, which disappear once it’s cooled down, often point to an internal hydraulic leak i.e. the leakage gets worse as the fluid viscosity drops, to a point where the pump can no longer provide sufficient flow to overcome the leakage and the pressure drops, resulting in clutch slip and the failsafe error.

You really need to get the codes read so that we can see what’s causing the failsafe condition to be flagged. Without this information, we’re just guessing.

Phil

Thanks Phil,
Will my IID give you the right info or do I need a garage?

Len Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

I think it will, though I don’t know if it uses the Land Rover P-code system (e.g. P0732=2nd gear ratio fault, etc.). If not, hopefully it provides a description of the fault.

Phil

Interestingly this morning I drove to an appointment and normally I would expect trans failsafe as soon as I pulled off as always seems to happen when engine etc cold - it didn’t happen! Same drive back home still no problem - 8 miles each time. I took live readings so have a massive pdf to look at, recorded solenoids pressure and shift, plus system pressure, engine speed.
As I lost more ATF when checking level I’m wondering if too much actually in, and now less due to loss could this have been the issue (although I have driven the best part of 30k like this)?

Len Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

PM sent lenb

After 2 days of no problem it all of a sudden does it again, the fault codes are:

ECM-Engine (ME7.2)

0x48C Electric thermostat circuit fault
0x404 O2 sensor heater circuit bank 2 downstream sensor fault
0x414 O2 sensor circuit bank 2 downstream sensor
IP-Instrument Pack

0xBD EBV function fault received from ABS ECU
0x90 Ignition sense incorrect
0x8D Transmission Interface Bus fault
LCM-Light Control v12+

0x59 Transmission emergency program fault
PATS-AntiTheft

0x23 Key 2 - Random code tolerance increased
TCM-Transmission

0x20 Output shaft speed sensor fault: General fault

Does this point to anything specific? Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

Unfortunately, the IIDTool codes (0x8D, 0x59, 0x20) mean nothing to me – I wish they’d translate them into the Land Rover P-codes.

The most common causes of TRANS FAILSAFE PROG are nothing to do with the transmission itself i.e. low battery voltage and a poor/intermittent voltage signal from the transfer box shift motor potentiometer. The latter also often produces an output speed sensor error (note that this is never a fault with the sensor itself, it’s just the controller saying the measured speed doesn’t compute).

Will your transfer box shift into low range with no problems, and then back into high range again?

Phil

Thanks Phil,

I haven’t tried low/high when it’s happened yet so will next time. Just off out now so if it happens will give it a go and report back once I know.

Thanks again

Len Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

Well it went straight in to Trans failsafe so I was able to check, Low box and high box was still selectable. Switched off and restarted and been ok since, stopped at my destination for 90 mins, just popped back home and all ok.

Len Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

I took some live readings with my iid tool and this time ‘failsafe’ happened again. One of the readings showed transmission system pressure which dropped each time I selected drive or reverse. On pulling away and as it tried to move to 2nd gear the ‘Trans failsafe’ happened and the pressure dropped to zero - where it stayed until I was able to pull over and restart.
Is this significant or to be expected?
I have a pdf of it but not sure if this can be uploaded.

Len Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

Can I only get a speed sensor from USA?

Both my diagnostics and my garage diagnostics says ‘output shaft speed sensor fault’ so I would like to try this before possibly committing to a full gearbox. At the same time I’ll do another filter and atf change (last one done 30,000 miles ago).

Any suggestions other than USA?

Len Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

As I previously mentioned, it’s extremely unlikely to be a fault with the sensor itself. I have a box full of the things, they never fail. If you want to convince yourself, just swap the front and rear sensors (they’re identical) and you’ll see that the error still relates to the output speed sensor. In the unlikely event that it is a sensor fault you can buy new ones from Land Rover, BMW and Jaguar or from a ZF spares supplier like JPAT or Sussex Autoparts. Alternatively, I can supply you with a used one from my collection

Click image to enlarge

Thanks Phil

I suppose I’m hoping it’s not the big fail!! 95% of the time it happens when cold, today had no problem driving to MOT and then back afterwards, but then just been out and it’s done it twice - the 5% when hot! It always does it going in to 2nd and always failsafe in 4th.
So the other question is: do you still recondition them? (My garage can remove and replace). If not do you recommend anyone nearer to me in Leicester.

Len Current: 2004 Vogue 4.4 V8 - 2004 Discovery 2
Previous: 2000 P38 DHSE - 1995 P38 DT Man - 1990 3.9 SE Classic, 1980 3.5 Classic 2dr

I usually keep a re-manufactured ZF 5HP24 032 model (Range Rover) in stock for immediate delivery : https://www.fullfatrr.com/forum/topic51883.html

I charge the same whether I rebuild your own transmission or supply you with one off the shelf. They require the same new parts and the same time spent on them.

Having said that, yours isn’t failing in ‘the usual’ way, and may still deserve some further investigation before chucking in the towel. I think it might be worth swapping over the two speed sensors. They can pick up metallic swarf suspended in the fluid (the ends are magnetic) which can cover the end of the sensor and interrupt the signal, or possibly you might spot a fault with the wiring? May be worth a look, though clearly if there’s metallic debris floating around in the fluid you have other problems!

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