P38A Can the air suspension be controlled without the entire wiring loom?

Is it possible to run the EAS system without the rest of the ECM/BECM and wiring loom?



For reasons unimportant to this thread. Such as using the EAS system on a different vehicle, or using the p38 as a stripped down off roader, is it possible to get rid of the need for the key fob, the EKA lockout, door locks and the display screen, but still get the EAS to operate?



i.e. just use the height sensors and the ride height selector switch to control the valve block and compressor?

300bhp/ton said:

Is it possible to run the EAS system without the rest of the ECM/BECM and wiring loom?



For reasons unimportant to this thread. Such as using the EAS system on a different vehicle, or using the p38 as a stripped down off roader, is it possible to get rid of the need for the key fob, the EKA lockout, door locks and the display screen, but still get the EAS to operate?



i.e. just use the height sensors and the ride height selector switch to control the valve block and compressor?

Click to expand...

The EAS ECU does use road speed input amongst other things, but with a bit of research, I'm pretty sure it could be made to operate as a stand alone system.
Getting rid of the BECM is a much bigger challenge.

300bhp/ton said:

Is it possible to run the EAS system without the rest of the ECM/BECM and wiring loom?



For reasons unimportant to this thread. Such as using the EAS system on a different vehicle, or using the p38 as a stripped down off roader, is it possible to get rid of the need for the key fob, the EKA lockout, door locks and the display screen, but still get the EAS to operate?



i.e. just use the height sensors and the ride height selector switch to control the valve block and compressor?

Click to expand...

IIRC someone had a test rig they could control the driver pack with independently of the EAS ECU. Might have been @pwood999 or possibly @martyuk ?

Grrrrrr said:

IIRC someone had a test rig they could control the driver pack with independently of the EAS ECU. Might have been @pwood999 or possibly @martyuk ?

Click to expand...

I started on a test rig, but direct control of the driver pack amounts to a manual system rather than automatic.

The ride height switch uses some form of serial communication to the EAS ECU from memory, so don't think you would be able to use that standalone to raise/lower the vehicle.

The control of the driver pack is just s 12V high signal to activate the solenoid - the driver pack then does the higher current drive of the solenoids.

The easiest way that you could (in my view) do a semi-automatic system would be to used the height sensors, an up/down switch (it might be possible to find how the rocker switch communicates to EAS ECU and mimic that) and something like an arduino.

You could then read the height sensors on 4 analog inputs, have an array inbuild for your height settings that the sensors need to match, with some tolerance in there... You could feed the compressor overheat and the pressure switch into digital inputs. Rocker switch for up/down height selection and then program it that way. The outputs would pretty much be the solenoids to the driver pack (which would need the microcontroller output to drive a transistor to pull the signal to 12V rather than the 5V most microcontrollers work on) and the compressor output.

It wouldn't be too hard to program a basic system up - it might take a bit of fettling to get it to work properly - maybe averaging readings of height sensors for example so it's not constantly trying to adjust etc... but definitely doable.
There was a guy, Nigel Hewitt I think who did it in a P38 and replaced the controller in the EAS ECU with a microcontroller to run his EAS. But in some ways it would be easier to do something like that standalone for another vehicle.

martyuk said:

There was a guy, Nigel Hewitt I think who did it in a P38 and replaced the controller in the EAS ECU with a microcontroller to run his EAS. But in some ways it would be easier to do something like that standalone for another vehicle.

Click to expand...

Fascinating: http://www.nigelhewitt.co.uk/stuff/eas/index.html

Thanks for the replies. Pretty much what I thought it would be, i.e. not exactly straight forward or easy.

I wonder if something like these could be used with the Range Rover air springs, I don't see why not. It wouldn't automatically raise and lower itself, but tbh I'm not that fussed. Just a low entry level, normal road height and extended modes would be all I'd want. And I'd want to be in control of when each was selected.

https://www.airliftcompany.com/products/compressor-systems/wirelessone/

Be pretty easy to fit a "low rider" kit I'd guess.

Low rider wouldn’t be any good off road. Just need a way to control how much air is going into the air springs.

You may find something in the sport system as mine doesn’t raise or lower, stays in standard height unless operated by pressing the console switch to raise or lower.

You wouldn't need to self level off roading?
You just want to jack up and roll in?
For the sake of easy offroading, maybe keep it simple,
for extreme off roading, why not springs?

Didn't they put air bags on a classic in Car SOS? Don't know how it worked though. Also do the tech docs for Nanocom give any help?

EntropyUK said:

Didn't they put air bags on a classic in Car SOS? Don't know how it worked though. Also do the tech docs for Nanocom give any help?

Click to expand...

IIRC the later soft dash Classics had air suspension as standard - a test-bed for the P38.

Pete

300bhp/ton said:

Low rider wouldn’t be any good off road. Just need a way to control how much air is going into the air springs.

Click to expand...

They don't stay low! Same principle; same kit.If you can pop into Activ-Air in Aylesbury (up Rabans Lane) then a couple of the guys in the workshop have helped fit kits before. They might even have some ideas of how to do it simply and cheaply for off-road. They don't tend to be around on Fridays but if you catch them before or after they're back from jobs they're pretty good.

Grrrrrr said:

Fascinating: http://www.nigelhewitt.co.uk/stuff/eas/index.html

Click to expand...

Au contraire, I think it would be quite easy, just needs a bit of electronics knowledge and checking the wiring diagrams. For example, you don't need it to lower automatically at 50mph so no speed input required, probably just need to tie the input to the appropriate level.