2006 Limited Air Suspension Issue

[Minnesota_expy]

My 2006 Expedtion is having the weirdest air suspension issue, it seems unwilling to attempt to inflate passenger side bags, but won't deflate the driver's side, however when you start moving it goes back to normal, both sides inflate and hold their air correctly and it self levels as it should.

But if you stay still for a good 30 minutes, it says "Check Suspension" and when turned off it won't deflate the drivers side bags.

Attached picture is it sitting after eight hours without being run, left side held air, right deflated. as far as i know, it should deflate both sides when left in park and shut off.

Never had problems with it, it's perhaps the nicest example of a gen 2 expedition i've ever seen, it's minty fresh with less then 60,000 on the clock.

 

[GAINMOB]

I don't have the slightest clue but I will offer to look at doing the coil conversion and be done with dealing with these problems again

Mr. 10K

 

[5.4T]

You need a scanner to pull the codes. I would recommend :OBDLINK MX BLUETOOTH TOOL and download the Forscan app on your phone.
Nice expedition BTW that's a rare color!

 

[Minnesota_expy]

News! scanner tools indicate that it developed error code C1275, "Front Pneumatic Fault" since i did not have tools available to find out more about what in particular was wrong, i gathered it was a sensor since pump, bags and array where fine, took it to dealership and they did a test on the sensors, the front drivers side height sensor was stuck indicating "0.75" and that it was leaning 4 degrees driver side [Even when on perfect flat ground], thus it attempts to inflate driver side bags and deflate passenger side so it can maintain level.

This is a really stupid way to design such a thing, i don't know why they did not just put a little gyroscope in the dash or something to indicate level, instead of this complex arms attached to the struts that detect degrees of movement.

Ordered the Part on amazon, should get here tomorrow, will respond with more news when it happens.

 

[1997SCEBFEX]

good deal; hope it resolves your issue.

 

[Minnesota_expy]

Whelp, as i thought, it was a Sensor issue, the Ford Expedition/Navigator with air suspension balances itself using height sensors attached to the arms, the sensor itself is a rather primitive machine itself, but reliable, the sensor itself is called a rotary variable differential transformer, it has no circuits or anything on the inside, it's simply brings electrical current inside and changes the output voltage depending on the potion of the arm, this is why the Expedition's computer reads it measurement as fractions [IE, mine was stuck at 0.75] and not degrees of movement, some system in the Relay does some math and adjusts the suspension accordingly

While an ingenious idea, displacing the need for a computer run gyroscope to balance the vehicle, it does leave a weakness in the design, the sensors can become stuck or corrode over time, mine had become stuck and would no longer move with the suspension arm, thus it tipped my vehicle to one side, the computer thinking the sensor was giving out the correct reading, something it was not.

Anyways, here is the picture of the broken part, you can just see the corrosion of what 10 years of Minnesota winters has done to it, i made sure to dismount and clean the other three just to give them a longer service life