Ford Transit 2016 minibus power step

[jack2006]

We are converting our 2016 L4/H3 minibus to a camper and having issues with the powered step.

When we brought it the step would start to come out when door was opened, then start to close and then open again when sliding door was fully open. So it worked after a fashion.

Checked for error codes using ForScan and there were quite a few so reset these. Powered step now worked as expected so all appeared good. But when engine was started and tried to engage gear warning message pops up to say step is out so the engine switches off. This 'feature' can be disabled via the drivers assist screen by turning the step off but that's not ideal.

Using the service mode for the power step in FORScan it cycles out then back in with no faults raised. Cannot think of anything else as that suggests the hall effect sensors being used for out/in must be working?

Thanks, John

[p2thed]

A failing aux battery will also cause issues with these, but go over the test steps before replacing any parts

[jack2006]

Thanks for the service information and I will take step off and go through the mechanical items detailed.

The switch on the pillar is fine and have used that a few times to retract the step. The control module is easy to access as everything is stripped out. With regard to the aux battery this was discharged along with main battery as minibus has been stood for a few months while we have been working on it and only realised a few days ago when engine would not crank more than couple of turns. Recharged both but think about it this problem showed up since then.

One last thing, where did you get the service info for the step? I have been into FordEtis a while back and payed/downloaded the mechanical and electric schematics etc for our minibus but there was no real detail on the power step?

[p2thed]

The information is within the tsb section, i dont know if it is available within the payed service. I have a dealer login so i have full access.

[Altransit]

If your batteries were completely (or even nearly) discharged, then they are toast. Starter type batteries never recover from this state, and need to be replaced.
New batteries often have a warning not to let voltage drop below 12v

[jack2006]

One stroke of luck is that our minibus is conventional starter and does not have stop/start feature. Put the batteries back on a slow charge and they are fine so looks like its all good.

Managed to sort out the powered step by turning it off in the IPC using ForScan. It no longer appears in drivers assist and minibus starts and engages gear fine without cutting out. Next step is to unplug its controller and if no errors are thrown up put my own controller in to operate the power step.

[dumper]

Hi jack if you do wire it up independently can you report back on how the step on my van brings the yellow service now up but as soon as you turn the ignition on it flashes up step problem and then clears and doesn’t log any codes and sometimes it will not come out with the ignition off or will not stay out on manual.if I can I’d like to run it off the leisure battery thanks.

[jack2006]

Yes no problem. It might be a few weeks before I get around to building a controller as working of the roof at the moment building a roof rack to put the solar panels on.

I turned the power step off in the IPC configuration file (see jpg image) and that got rid of the issue with step being detected as being out.

Today I disconnected the power step at the harness on passenger side rear, is this where you have done it? Problem with this is it then threw up a DTC for the power step. So had a look at the modules it was finding and the power step module was still being scanned in the MS CAN bus but it now set a fault condition as the step was disconnected from it. Next step was to disconnect the power step module which is located on the drivers side rear and all good. Initialisation scan no longer showed the power step module (which was correct as it was disconnected) and no DTC's. Engine starts and gears can be engaged with no warnings or cutting out etc.

The step does need to come off though because it still has a fault somewhere that its controller was picking up and I guess this will be its sensors for open/close which I intend to re-use. Last thing I will do before taking it off is to re-connect and re-enable the power step module, use oscilloscope on the step open/close, hall effect transducer supply, hall effect signal and SSR return (whatever that is?). Using multimeter the voltages made sense on all connections except the SSR which looks to me like a waveform of some sort as voltage output very low when step is moving hence reason for scope.

[dumper]

Thanks no problem it’s not giving me problems I can’t live with it’s more of a nuisance for now.

[jack2006]

Update on the step.

Unbolted the actual step itself (4 x M6 bolts underneath) from the 2 brackets ready to strip the brackets out for repair. Thought I would just try the step again manually via drivers assist. Motored it out then back in manually before changing back to to auto-mode.

Bingo! engine starts and gear can be selected without warning message and the cutting of engine.

When I moved the unpowered hinge it was quite stiff but no notchy action. So it looks like the hinges (pins) need to be stripped, cleaned and greased. Someone did mention on the forum that these should have grease pins fitted and a bit of a dire design, think I agree!

[jack2006]

After removing the step platform and both of the hinge assemblies from minibus (one has the motor attached) ran a few checks.

There are the 2 power connections to the motor which are Brown/White and Violet/Grey. Briefly applying 12V to these will attempt to motor the hinge either in or out. If it tries to motor in lets say and its already in the motor will protest because it has stalled hence brief connection. swapping the wires will motor the hinge in opposite direction. This function of providing power to the motor and reversing connections for opposite direction is done by the 2 relays (Black cased items) on step module PCB picture.

The hall effect sensor signal (displayed on the oscilloscope, picture attached) is only present when the step is moving. This signal appears on Grey/Orange, the Grey/Brown connection had +10V DC supply with respect to the Blue/Green which was 0V return.

It is assumed that the hall effect signal (square wave on scope) is used by the power step module to detect that the step is moving and if/when it stops, i.e. end of travel to cut supply to motor via control circuitry. Because the signal was not encoded with exact angular position I assume that the module counts the pulses from the hall sensor and 'knows' approximately how many should be read for fully open or fully closed. So if not enough pulses are counted step module thinks the step is still out. Just a guess but cannot see how else it works.

With regard to detecting if the step has hit some obstruction when motoring this will be done by the current sense resistors on the step module PCB (see photo of modules PCB). These resistors could also double up to stop the motor when the step hits the end of its travel as motor will stall.

So if step hinges are stiff then the motor could stop on current limit before enough pulses are counted from the hall effect sensor so step module would think the step was still out, which in my case it was but not by much.

Anyway next job is to design and build a controller to do similar job to the Ford one but with manual buttons for open and close and not switch the engine off!! will have a warning buzzer though etc.