Got an urgent program whilst on holiday down in Somorset - some 170 miles from home.
L322 Vogue (2006) automatic is driving fine but suddenly loses its gear. Its as if it is in neutral with the engine reving but no gear. I pull over, select park, stop and start the ignition and it drives fine again for a few minutes - changing gear fine - then loses gear again. The selector remains in drive the whole time. The error message that appears on the dashboard is "Trans. Failsafe Prog."
I am going to take it to the nearest local garage tomorrow and hope they have a code reader but it sounds like an electircal fault to me. Does anyone know if this is suggestive of a particular issue?

I admire your optimism, but I think it unlikely that it’s an electrical fault. Your transmission should drive in its failsafe gear (and reverse) without any electrical input whatsoever. There are so many mechanical and hydraulic issues with the GM 5L40-E transmission in the Range Rover that it would be pure speculation to guess which particular one has befallen your car. Hopefully the codes will give some clues, if you can let us know what they are.

Phil

Thanks Phil, got to be optimistic when you go touring in the family RR!
IID tool left at home when came out on holiday so will need to wait till it is towed back on saturday. I only felt it could be some sort of sensor or other electrical issue because resetting by switching the ignition off and on provides transmission once more. Other threads describe this error message with faulty potentiometers in the transfer box stepper motor or a faulty neutral sensing switch - I wondered if these would describe my symptoms?
Although the failsafe prog message does come one the car does not dirive in its failsafe gear - no gear other than neutral appears to be selected - could this be the symptom of a faulty neutral sensor switch?
The transmission codes I got from a random garage near the breakdown site were:
0x0036 - consult service manual
0x0037 - Front axle precharge valve

Not sure how useful or complete these are but will post hopefully more codes from my IIDtool when get back to base.

I am still waiting for my garage to read the codes but my own IIDTool is returning only unknown errors from the potentially relevent modules. These would be:
TBOX-Transfer case ECU: 0x5212re - Unkown
TCM - Transmission GM ECU: 1/2 0x0035re - Unkown
2/2 0x0036re - Unkown
Not sure if this helps - it seems the GAP IIDTool is not sufficient to read the gearbox errors

Like you say, unfortunately those codes aren’t very enlightening .

Just a few questions :

When you move the gear selector from Park to Low and back again, do the corresponding lights (P,R,N,D,L) light up on the dashboard?

When you have Park selected without the handbrake on, will the vehicle move if pushed or on a slope, or does the park lock hold it stationary?

When you move the gear selector from Drive back into Park (with the engine running), can you hear a loud grinding/ratcheting noise for a few moments?

With the 5-speed petrol models (ZF 5HP24 transmission) you can disconnect the 16-pin plug at the rear of the transmission to force the transmission into failsafe mode which will should then engage the default (4th) gear. This would have been a useful test. Unfortunately, the 5-speed diesel models (GM 5L40-E transmission) like yours have additional wiring to this plug (20 pins not 16) for the internal inhibitor/gear position switch and (having never tried it) I’m not sure what would happen if you disconnected the plug.

Phil

Hi Phil,
The car is now at our garage about 20 miles away. I am hoping their code readers will produce more information. However, I can answer your questions from memory.

When you move the gear selector from Park to Low and back again, do the corresponding lights (P,R,N,D,L) light up on the dashboard?
I am pretty sure that they do - will ask garage to check. In fact everything seems to behave entirely normally until the fault occurs.

When you have Park selected without the handbrake on, will the vehicle move if pushed or on a slope, or does the park lock hold it stationary?
Yes, it definately does hold it stationary.

When you move the gear selector from Drive back into Park (with the engine running), can you hear a loud grinding/ratcheting noise for a few moments?
No, it sounds perfectly fine.

Update:
Unfortunately garage was unable to read the only recurrent error code: 0x0036 (unkown). From the live data it emerges that the warmed up transmission gets stuck in 5th gear when in high range. On slowing or stopping it fails to shift down or return to first gear, unless you switch off and switch on the ignition again when first gear is once more selected. If you drive slow enough to never go above 4th gear there is no problem. Similarly if you start off in low range there is also no problem.