Erratic EAS height going to raised

[ian4002000]

Whilst driving along in my P38 the suspension is often going to raised height for no apparent reason, it will often return to normal during the trip and will even go to raised again. It will lower itself if the lower button is pushed but can at any time return to raised.


Has anyone had this occur before ? Any ideas what may be causing it ?


I have done quite a lot of work on the EAS over a few months but this problem has been with the car for over a year. The EAS seems to work ok, except that it will usually trip out after approx. 15 minutes driving. I have assumed this was due to the compressor running too long and I have since located a couple of small leaks and all seems well except the compressor still runs too long which I am now thinking is caused by this constant changing of ride height.


Ps the ride height changed even when the override switch was on.


All thoughts appreciated....


Ian
Bittern Vic

[davidsonsm]

Have you carried out a valve block rebuild? Sounds to me like a dodgy non-return valve within the block. That's just top of head response.

[ian4002000]

Yes, the valve block has been rebuilt and rechecked on the weekend. found a small airleak and rectified. the compressor has reasonable output and gets to 145 psi before turning off. I have installed a tyre valve and guage onto the air tank line to reduce the amount of work the compressor is doing during testing.


I did see a small air leak at the bottom of a rear air bag at full extension and I am wondering if this would cause the system to go into extended height if it was constantly leaking ???

[Keithy P38]

Extended height is designed to be triggered if more than one height sensor has been detected as "unable to lower" (which indicates wheels may be either hanging in the air or the vehicle has "bellied out", as a result it further inflates in an attempt to lift the vehicle over the obstacle, or provide grounding for at least two wheels in order for the vehicle to drive away/off the obstacle.

Perhaps you have an exhaust valve that's sticky or a height sensor on the end of its life?

Cheers
Keithy

[TheTree]

Hi

Do you mean "offroad height" or "extended height"? They are not the same thing.

I too would be looking at the sensors and possibly the valve block driver

Steve

[finallyrangie]

Might be worth swapping the sensors left to right just as a test, might be a free fix but it's unlikely that they would all be out of range both ways up, could help isolate the driver as the problem, suspension driver, not vehicle driver that is!

[ian4002000]

Hi

Do you mean "offroad height" or "extended height"? They are not the same thing.

I too would be looking at the sensors and possibly the valve block driver

Steve

Thanks everybody for your help ! Most appreciated !


How do I tell if it is off road height or extended height ? The car is in high range and highway speeds and can be in highway mode.


My thinking at the moment is that the right rear airbag has a leak at the low height setting, this may be what is causing the system to be constantly adding air to the RR, after a few minutes the car then raises, and a few minutes later the whole system trips out on error, possibly a hot compressor or the system just gives up. ( it takes approx. 15 minutes for the system to trip out )
My wife does a lot of five minute trips during the week, so the tripping out error is happening only about once a week or less.


Does this make sense ???


Ian

[finallyrangie]

if you are doing lots of short trips it might be an idea to check the battery has a full charge before you start chasing the error, ,low charge can give all kinds of strange effects

[TheTree]

Hi

I think you are at offroad height, there is an emergency extended height that the beast will go too if it thinks it is stuck.

No idea how it works out if it is stuck though .. some kind of LR voodoo no doubt

Steve

[p38arover]

No idea how it works out if it is stuck though .. some kind of LR voodoo no doubt

Read the EAS training documents I posted in the Files Area.
http://www.aulro.com/afvb/local_link...id=248&doit=Go