Air suspension issues - totally bizzare

[andrewwynn]

You need to investigate left front sensor. If the corners are all deflated, the sensor values should be similar.

Running no fuses suggests wiring cross wire somewhere like a subwoofer tapping power and back feeding a circuit downstream of the fuse.

It does look like the correct fuses pulled. I would pull the relay it must have one.

Does it shut off when you remove the key or have to pull the battery cable?

[Homerlovesbeer]

I have to pull the battery to shut the compressor off. I've never had this issue before and when I had the rear bags go flat due age, pulling the fuse stopped it then.

It's bloody weird!

I've not had this problem before and this is really odd because I haven't touched any wiring, only took 2 air lines off the valve unit to do the rear suspension.

I'm hoping I haven't stuffed something up going through all the diagnostic stuff trying to level it

[andrewwynn]

Well start at the known issue; odd sensor value.

When my e seventy was aiming the headlights incorrectly i used realtime monitoring of the level sensor to determine the bar was the wrong one.

Disconnect the bar and sweep the lever while monitoring.

Disconnect the air compressor at the compressor so you can have the fuses in but it won't run the compressor all the time.

Maybe disconnect the ground if it's not a plug so you don't short it out.

Shorting the power to ground is the easiest way to determine which fuse is actually powering the thing though going through fifty fuses might not be "easy".

[Homerlovesbeer]

Originally Posted by andrewwynn

Well start at the known issue; odd sensor value.

When my e seventy was aiming the headlights incorrectly i used realtime monitoring of the level sensor to determine the bar was the wrong one.

Disconnect the bar and sweep the lever while monitoring.

Disconnect the air compressor at the compressor so you can have the fuses in but it won't run the compressor all the time.

What do you mean by "the bar was the wrong one:?

I'll try disconnecting the front left sensor however I'm not convinced this is the root cause of my problems

[andrewwynn]

On my e seventy, the front level bar was not the correct model. There are like four different sizes. It was apparently replaced with the wrong one. I had to shorten it until the headlights no longer pointed into the dirt.

[andrewwynn]

To be clear, disconnect the bar that goes to the level arm. So you can sweep the arm full range to confirm the sensor is doing its job.

Correct it's likely just one piece of the puzzle but you have to start with fixing the known problems.

Are you sure it's the compressor running?

Any chance the recent work pinched a wire bundle causing a hot to compressor short causing it it always run?


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[Homerlovesbeer]

Originally Posted by andrewwynn

Are you sure it's the compressor running?

Any chance the recent work pinched a wire bundle causing a hot to compressor short causing it it always run?


Sent from my iPhone using Tapatalk Pro

I'll take a video shortly to demonstrate but I'm sure I didn't damage any wires.

I'll remove the LH front sensor and graph movement also.

Thanks for your input!

[andrewwynn]

The compressor is supposed to run when the tailgate is opened. Shouldn't with no fuses so that's another issue. Previous owner maybe modified something?

I never pulled the fuse when doing suspension work: the cat knows what being on a lift looks like and disables itself.

[Homerlovesbeer]

https://youtu.be/KZ0H5-BsLFc?si=SwoG0b5L3HJxm6yr

Video up showing the issue. The compressor runs, stops, then vents, runs, stops, vents over and over.

I may add that the solenoid is constantly activating, along with the compressor, to try and add air into the front and rear bags.

I unscrewed the lines from the rear bags and 1 front to test and the air leaks out and then when the solenoid activates the air flow increases then tapers off again as the solenoid closes.

I think the accumulator isn't supplying enough pressure to raise the car, my best guess now. Why that is happening?

Either the compressor is running but not producing airflow or something is wrong at the accummulator.

Where to now?

[Homerlovesbeer]

Yep, just as I feared. It seems nobody has seen this issue before