L405 2014 AB SDV8.

Side steps have a mind of their own... sometimes they come out, some times they don't. Some times they come out on one side only.. very frustrating what you need them to climb in...especially what I have a pregnant misses, and a 94 year old grand mother to contend with.

No fault codes at all on the IID Tool.

Help very much appreciated

there are a few plugs underneath so i would check thise first...

Thank you.

I have unplugged them and WD40 them up and it's still the same unfortunately. Is there anything else I can check or do? It's very annoying. It happens in bouts, it can be totally fine for a whole week and then start playing up for 2 weeks... I'm stumped

does this happen after rain?....this maybe suggests water is still getting in somewhere ..or it could be an electronic gremlin..

Could be a module that is located against the transmission tunnel at fault, plugs lose? or the switch in the overhead consul these are plugs that are easy to check?

Mine behaved similarly until I lubricated the moving parts, been ok since - suspect the antitrap was kicking in on occasion.

Tinman wrote:

Could be a module that is located against the transmission tunnel at fault, plugs lose? or the switch in the overhead consul these are plugs that are easy to check?

The OP has a 405 so the module is in the right rear compartment behind the seat bolster... And the switch is in front of the drivers right knee sir...


I would try a battery reset first, then check the connections are all good, then replace the switch (as its the cheapest) then the module (remembering to buy an age appropriate one as the can-bus changed on later years)

There is a software update for this issue available from the dealer network. However, the deployable side steps have an “intelligent “ feature, that kicks in if the vehicle detects it is being driven over rough terrain or off road. In this scenario the steps will not deploy until back “on road”.

I had this exact fault with erratic side step behaviour - the dealer (who I have no faith in at all after they damaged my car whilst it was in recently for a reversing camera issue) told me they had updated some software.

In truth, I didn't know if I believed them because they were so awful to deal with but this does lend credence to the story that there is a software update available.

I get the car back later today so will let you know if the behaviour of the steps has improved 2016 (L405) Autobiography in Black with Ivory - for ULEZ
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They have an anti trap feature and the steps predominantly work off the terrain response system hence switches off in mud n ruts etc etc... not heard of a software update but I will check later when I get back 👍

Last edited by Cam-Tech-Craig on 21st Dec 2018 11:56am. Edited 1 time in total

Thank you all for the input. Interestingly I have a static fault in the terrain module, something along the lines of quqesent (if that's how you say it) voltage issue. When I questioned the dealer recently they said "it's perfectly normal to have this fault in the terrain response unit" however, if I turn the terrain response off, by clicking the knob so it sticks out, I have no difference (except the junction full lock shudder goes away) in the behaviour of the steps.

How might I lubricate the mechanism to prevent the anti trap from kicking in?

160dmb wrote:

I had this exact fault with erratic side step behaviour - the dealer (who I have no faith in at all after they damaged my car whilst it was in recently for a reversing camera issue) told me they had updated some software.

In truth, I didn't know if I believed them because they were so awful to deal with but this does lend credence to the story that there is a software update available.

I get the car back later today so will let you know if the behaviour of the steps has improved

I will eagerly await your update. I have also lost faith in the dealer...

I used a spray on white grease with an extension tube attached to the nozzle (like you get with a can of WD40) to get it directly into all the pivot points, I operated the steps multiple times by opening / closing the door and this seemed to free up the movement, whereas they used to start to extend / retract then stop, one side would be out whilst the other in etc, but now all seems ok for me.

As JCW says...plus just be prepared to manually "help" the step out and back the first couple of times if its sticking. Also important to do the motor spindle as well as the step pivots (that was actually the critical area for mine second time of sticking)...admittedly on the L322. Mike - MPx

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I lubricate all my customers steps (using white grease) at service point...

I then lock & unlock the car a few times to work them...