Car: 2015 L405. Less than 80000 km.

Deployable tow-bar last used in December. Now stuck in retracted position.


Symptoms:

When pressing the deploy button, the tow-bar motor runs for a split second, then the red and green diodes start flashing and the alarm goes off. The tow-bar doesn't move at all - or at least I cannot feel anything with my hand.


Troubleshooting performed so far:

Made at least 10 attempts with resets per service manual instructions. Every attempt to deploy the tow-bar results in the symptoms described above.

Checked battery voltage and added an additional battery to make sure it is not a voltage problem.

Checked that tow-bar control module is within the range of good modules per the service bulletin.

However, I have not removed the tow-bar, just inspected from below and lubricated the lever for the 12-pole trailer light socket.


Question:

Since the tow-bar doesn't move at all, my guess is that this is a gearbox problem, and that I should order a motor and gearbox combo from Powerful UK.

Any other ideas?

Last edited by Boatmechanic on 26th May 2024 1:59pm. Edited 1 time in total

Have you tried spraying it with WD40 ? and maybe trying to pull it down when the motor engages ?

There's this thread, but I don't think it adds much more - https://www.fullfatrr.com/forum/topic55975.html

I sprayed WD40 (or rather, something similar), on the lever for the socket for the trailer light connector.

I can't get to the mechanism for the tow bar from below. Since I haven't removed the tow bar, I haven't sprayed that mechanism. It seems quite well-protected, though.

Last edited by Boatmechanic on 26th May 2024 1:58pm. Edited 1 time in total

By the way, the sound it makes when trying to deploy is something like this:

knock-knock-knock
swish-swish

Then beeeeeeep.

Powerful have a video for the L494 tow bar, which I assume is very similar. There may be some pointers in there ? (I haven't watched it all)

?si=mP1xRbYmR2lMTMM2

Thanks!

Watched that one earlier today, and probably read a dozen threads here and on that other forum.

A couple of bits from the manual -

If an obstruction is detected during operation of the electrically deployable tow ball the button's LED indicator lamps flash. A 10 second warning tone also sounds. In this event, press the deploy-stow button while the LED indicator lamps are flashing, to reverse the movement of the electrically deployable tow ball.

NOTE:
The operation of the electrically deployable tow ball may also be affected by debris. For example, mud, ice, etc. In this event, press and hold the deploy-stow button to increase the power supplied to the tow ball motor.

Thanks!

This is not a 10 second warning tone. It goes on and on and on.

Press and hold does not help.

They are known for seizing so that would be my starting point. Only Range Rovers since 1988

IMHO deployable towbars are like locking wheel nuts and deployable steps, remove them all and throw them in the bin... all they do is seize up and fail just when you need them...  Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

A bit harsh Pete! The alternative is a combination of regular use and regular maintenance (clean/lube) - works for me anyway, and I'd rather have them. Though obviously not the locking wheel nuts - they are just hopeless. Mike - MPx

2017 5.0 V8 Supercharged SVAutobigraphy Dynamic SVO Palette Grey (2021-...)
2012 5.0 V8 Supercharged Autoboigraphy Orkney Grey (2017-2021)
2007 4.2 V8 Supercharged Vogue SE Tonga Green (2012-2017)
2002 4.4 V8 Vogue Bonnatti Grey (2008-2012)

My life is better without them... I'm sure if you lavish time and lube on them they last a bit...

 Pete

__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Parchment over Navy Interior. Sold
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand, Jet Interior. Sold
2002 L322 Vogue 4.4 V8 Epson Green, Ivory over Aspen Interior (Fatty Offroader) Sold
-Click for Project Fatty off roader-

MPx wrote:

A bit harsh Pete! The alternative is a combination of regular use and regular maintenance (clean/lube) - works for me anyway, and I'd rather have them. Though obviously not the locking wheel nuts - they are just hopeless.

Well obvs the steps cycle everytime its locked/unlocked or a door opens. They get cleaned like the rest of the car (jet wash, snow foam, jet wash, two bucket sponge, jet wash, dry) probably every 3 or 4 weeks. I lube less often - Craig does it for me in the Jan service and I'll do it maybe one other time through the year. Its all of the pivot points in the brackets and the motor drive shaft.

My tow bar gets used maybe once a month (bit less regular in truth but I'd guess never left for more than 3 months before a few cycles over a shorter period). I just look at it when its moving. If it seems in any way laboured I get the lube out (easist to see in the connector socket than the tow bar itself). I lube any pivot points I can see with the long straw on the can - I use a silicon or PTFE spray not standard WD40. Do it maybe twice a year. The car is only 7 years old so maybe not had time to really deteriorate - but I have had the odd steps refusal and the odd time where I manually help tow bar deployment - just gives me the kick I need to clean and lube again.

In general I'm a believer in the idea that its worth cycling through stuff that's rarely used from time to time to ensure its not got stuck - say 2 or 3 times a year. (Eg off road height on the suspension) Better to find out any bad news when you don't need it rather than when you do! Mike - MPx

2017 5.0 V8 Supercharged SVAutobigraphy Dynamic SVO Palette Grey (2021-...)
2012 5.0 V8 Supercharged Autoboigraphy Orkney Grey (2017-2021)
2007 4.2 V8 Supercharged Vogue SE Tonga Green (2012-2017)
2002 4.4 V8 Vogue Bonnatti Grey (2008-2012)

Thank you!

My towbar is used monthly, except in the winter. Hence the pause from December until now.

Never had any problems with it not wanting to move, except due to low battery voltage.

Is my understanding correct that what you do is to spray some silicone spray in the tow bar opening under the car?

I.e. no disassembly except the cover plate under the car, and no particular washing routines?

I was thinking of dropping the whole tow bar assembly so that I could get at it from above...