air pressure preset function doesn't work properly

[Jan VM]

air pressure preset function doesn't work properly because I cannot set the air pressure stable. If I push the button when the pressure is on 40, the pressure changes (from 36 to 48) so it's impossible to set the other air pressures at the same pressure because it changes. We have checked the ground connection, and this is ok. Our sending unit is mounted on the solenoids.
Can anyone give me a possible solution??? (other than the solution in the troubleshooting...)

Thanks in advance

[britt@ridetech.com]

What control system do you have? Since you mentioned "Troubleshooting" I'm guessing you have an e3.

Are you changing the pressures on the rear or the front?
If you inflate only one air spring all other air spring pressures will change slightly as weight is being transferred around the car.

To set the presets manually raise the vehicle to the destination (when possible push both front inflates together and both rear inflates together, this will keep you from cross loading the vehicle inadvertently).
Once you have everything at the desired pressures (when sitting still the pressures will remain stable unless the vehicle is moved or load is changed), you simply press and hold the desired Preset button for longer than 5 seconds.

If you are trying to hit 40psi EXACTLY I think you are being to precise. Once set the air pressure only presets have a window of +/-7psi (so if you set it at 40psi the software is allowed to stop between 33psi and 47psi). Though it is typically within +/-2psi. If we make it exact it takes 30 minutes to hit the exact number as it will keep inflating then deflating, then inflating, then deflating, ect.

If you need to be that exact you need to add level sensors. With the addition of level sensors the system now knows EXACTLY where the suspension is, and can calculate load by looking at both pressure and level.

Remember, air pressure is only an indication of vehicle height, it is not a direct relationship.

[Jan VM]

The system I use is the ARC4800e Big red max compressor kit w/dual Viair 400 compressors, dual 5 gal. tanks...

We mounted the system with one tank in the front and one in the rear. the solenoids and sending units are placed near the wheels

I have bought it a few years ago,to place it in a hotrod we're building. This is already an older system because the hotrod building have taking a few years (+-6) to complete.

I'm quite sure that I have one pressure sensor who fails. Everytime we push the button, it goes up and fall down to 2psi or 3psi. There's no pressure leak, and the air bag stays on pressure. This is a problem that only occured a few days ago, before the pressure sensor work properly but everytime we wanted to put the car on the destinated rideheight, it always overshooted the preset height. It may be because of the front of the car is very light and the front shock absorbers are shock waves. What can I do to prevent overshooting the preset?

Normally the sending units are placed straight on the solenoids, they all have a very good grounding, we have tried about everything but it doesn't seem to work.

I need one sending unit DIG 1051 very urgently (is it possible to order online?)

thanks in advance

ps: pictures attached

[britt@ridetech.com]

I notice a few things that will contribute to your overall issue:

1-Pressure Sending Unit
-you'll need a new part
-as we haven't used those sensors since 2006-or-so they are not on the website. You'll have to call the sales staff to order (I think we still have a few left)
-I would purchase 4 sensors. If one failed now, the rest are soon to go as well.

2-Big Reds + 10 gallons of air +1/2" airline + small car = Disaster:
-Can you manually get the vehicle to the desired height?
Basically you have WAY too much compressor system for that vehicle. Big reds on a vehicle that has only 50psi at ride height is VERY difficult to control.
If you can get the vehicle to height manually the computer should be capable of doing the same if everything is working correctly.

-The #1 thing I would do is change the front air line to 1/4". This will help TREMENDOUSLY! (for reason, please keep reading)

Now, about overshooting:
The system inflates past the preset destination then deflates down to the desired preset pressure. This eliminates any suspension bind you may have. If three air springs go over (as they should) but one air spring does not (due to faulty sensor) they will not deflate. It waits until all 4 air springs are over the preset pressure before it deflates.

Vehicle Configuration:
I can see you have double convoluted Shockwaves on the front, and a 7000 Series rolling sleeve on the rear. However, it appears as though you have either a VW drivetrain or an East-West 4 cylinder in the rear using independent suspension.

What pressure does it take to get the front and rear to the desired ride height?

Here's the situation: Double convoluted air springs lift more weight than rolling sleeve, so they should be used on the end of the vehicle that weighs the most (when appropriate weight dictates their use). With Big Reds, 1/2" airline, double convoluted Shockwaves, and no front weight that front end should almost bounce off the ground when you inflate it. If you keep this configuration I don't see any way the e1 is capable of controlling it correctly.

[Jan VM]

Hello again,
this air ride system has been purchased few years ago (orderdate 08-12-2004) but it's only now we have finished the hotrod. How is it possible that there's allready one sending unit broken and the other 3 will likely follow? We have not even driven 1km with the car. I can only conclude that this is a bad product. Are you sure the other 3 units will stop functioning? They haven't been used. Can you suggest other sending units. If I have the buy 4 new sending units, I want other sending units which will function a much longer time.

[britt@ridetech.com]

The pressure sending units originally chosen for the e1 system were VDO units which are VERY durable. However, during the time we sold the e1 a large OEM customer came in and purchased all the stock VDO had, which meant they shorted our order. To fix things as quickly as we could we purchased direct replacements which were made in Taiwan.

These units, though they spec out exactly like the VDO's, are not quite as well built. The seals on the bottom tend to dry out and allow moisture inside the sensor. This moisture builds up on the electrical wiper arm which causes corrosion and eventually causes a failure.

We sell only VDO sensors at this time.

There are only two ways to make these live longer:
1-use them periodically. This "wipes off" the corrosion (not completely, but it helps).
2-if they are going to set on the shelf for a long time you should cover the end with a cap so moisture cannot get inside.

Like I stated before, I have concerns that even if you get the sensors working properly the e1 will not be able to achieve the proper ride height as the compressor system as a whole is much too large for that vehicle.

I'll do whatever I can to help. Let's get the sensors working then go on from there.
I will need to know a little more about the vehicle. There is never too much information!

[Jan VM]

I would like to order 4 VDO sensors, shipping to belgium. I have allready emailed twice to sales department but I don't get any answers. How can I order? Is it in the online catalog? thanks in advance

[britt@ridetech.com]

One of the sales guys should be with you shortly regarding those sensors. Not sure if we've discontinued them or why it's taking so long.

[Jan VM]

I hope to hear from them soon, It's an urgent matter and the shipping will take allready a few weeks. What do you mean by "we've discontinued them", Does it mean that those sensors are no longer available? It doesn't have to be that label, just sensors that properly work, without them, I cannot use the air pressure system.

Regards

[britt@ridetech.com]

I said I hope we HAVE NOT discontinued them.

Anyway, since you are in Europe, and the VDO sensors come from Europe, maybe you'll have better luck finding them locally.
They are used primarily for oil pressure and turbo pressure on many vehicles, including large diesel trucks.

Any of these part numbers will work:

Single Pole (grounded through sensor body)
360-081-029-012C
360-081-029-012K
360-081-029-042C
360-081-032-067C

Double Pole (ground supplied to secondary pole)
360-081-032-014C