Searched around for this type failure, and I find it odd. Apologies that this might be long and rambling.

Recently got the yellow ABC malfunction message. Happened after I felt a shift of sorts sitting at a light.

Got it home. Noticed left front is jacked way up to maximum. All the other wheels are somewhat normal looking, but right rear I can tell is not close to normal...it was a tad low. Playing with the height button got the left front back to normal yesterday.

Fire it up this morning, left front cranks up all the way again. No ABC message (only had it that once over this course of a couple days.) Of course it rides like a Jeep at this point.

So I yank out the DAS and see what is happening. There was only one stored code (and sorry, I cannot remember it after I put everything away, I think it was 1529 or something...left front shock circuit or something similar, I'll verify it again in the morning after yanking all the testing gear out again. Old age and all that, figured I could remember.)

Anyways, further testing:

Voltages for ride height sensors seemed ok with ranges given the height. Front left was 60mm, others were somewhat all over the place but within range.

Did a rodeo, front left stayed extended.

BAR was normal from the pump.

Finally, decided to dump the pressure. All corners then sat basically on the tires.

After the dump (which puked some fluid, making a nice mess) had it do a level and it brought every shock up to +1/-1 mm for height. Took it for a drive and all was well.

Fluke? Problems heading my way? I'm hearing a ticking sound that I think is coming from the tandem pump. Also, fully extended I could see the boot on the front left shock is completely cracked all the way around.

 

Taking it in tomorrow to an indy. Pentosin is slightly black. Still see some green but we will see. My thoughts are the tandem pump is slowly self destructing.

 

Well, car is back. They determined the tandem pump was bad which was my guess originally.

Checked out ok, shock seems good according to them, it clears the code where as before it wouldn't. Granted, doesn't make a lick of sense but rack it up to one of those oddball things.

 

Don't think the pump would affect only one shock.

It sounds like the travel sensor in the strut itself is failing. I'd plan on a strut replacement.

 

Yeah, I think we are headed there ultimately with a strut replacement. Travel sensor though basically measures the rate of travel...and is buried in the shock and shouldn't cause this situation. Ride height sensor would be the one that I would guess would be the failure.

But I read the sensors myself with DAS and all checked out OK before I dragged it in.

Like I said doesn't make much sense...but the tandem pump was clicking so it needed to go.

Basically what I think happened it caused the valve body solenoids to get clogged due to it going out. All 4 corners were wacky.

Perhaps I'm wrong, and if so I will keep things up to date.