Help! Suspension drops to bump stops when engine switched off.

Don1 · Jan 31, 2009

Hi All,

Please help.
2000 P38 4.6.
Used EAS unlock software to depressurize air springs and relaced a rear air spring. Car raises to all heights but now drops to bump stops immediately everytime I turn off the engine and hence takes ages to reach normal ride height.
Suspension worked fine before this work other than dropped height overnight due to small leak in air spring.
Any ideas please.

wills · Jan 31, 2009

Don1 said:
Hi All,

Please help.
2000 P38 4.6.
Used EAS unlock software to depressurize air springs and relaced a rear air spring. Car raises to all heights but now drops to bump stops immediately everytime I turn off the engine and hence takes ages to reach normal ride height.
Suspension worked fine before this work other than dropped height overnight due to small leak in air spring.
Any ideas please.

How soon is immediately?? Like turn engine off, car drops straight away before even exiting or turn off engine, get out, shut door and then it starts self levelling and eventually drops to the bumps??

-Wills

Don1 · Jan 31, 2009

wills said:
How soon is immediately?? Like turn engine off, car drops straight away before even exiting or turn off engine, get out, shut door and then it starts self levelling and eventually drops to the bumps??

-Wills

Hi Wills,
About 10 secs after turning off engine the solenoids start clicking and the car lowers in a controlled but quick decent. I have checked and only one corner was actually touching the bump stop so it may have dropped to access height. Not realy sure as I have only had the car a week and am not that familiar yet. Does this even if I don't open a door to get out. If I open a door it does not drop until it is closed. Left a door open for 5 mins to make sure it was not a fast air leak and no loss of height until door closed.

Any Idea's??

Thanks, Don.

wills · Jan 31, 2009

When you were playing with the EAS Unlock software did you mess about with the calibration at all?? It sounds like a dodgy sensor to be honest BUT this isn't definite. It could be something else like the drive pack on the side of the valve block.

You ARE parked on a flat level surface right??

You say the vehicle keeps height if you open the door and leave it which is good news as that would appear to indicate no air leaks.

You have the EAS Unlock software - get using it! Park it up on level ground and get out and hook up the EAS Unlock laptop. Turn engine off and then thurn the ignition back on (i.e. the stage where all the lights show)

Read the sensor values - what are they?? They won't all match, that's common but does one of them appear way out from the rest??

The problem your describing is the self-levelling feature of the EAS system whereby the ECU will look for the lowest corner when you park up, it will then lower the rest of the corners to this height. Lowest corners height changes as this happens and so the ECU does it again until your on the bump stops, annoying but normalish behaviour for the P38 IF parked on un-even ground.

So, get reading the heights and see what's what.

-Wills

Don1 · Jan 31, 2009

wills said:
When you were playing with the EAS Unlock software did you mess about with the calibration at all?? It sounds like a dodgy sensor to be honest BUT this isn't definite. It could be something else like the drive pack on the side of the valve block.

You ARE parked on a flat level surface right??

You say the vehicle keeps height if you open the door and leave it which is good news as that would appear to indicate no air leaks.

You have the EAS Unlock software - get using it! Park it up on level ground and get out and hook up the EAS Unlock laptop. Turn engine off and then thurn the ignition back on (i.e. the stage where all the lights show)

Read the sensor values - what are they?? They won't all match, that's common but does one of them appear way out from the rest??

The problem your describing is the self-levelling feature of the EAS system whereby the ECU will look for the lowest corner when you park up, it will then lower the rest of the corners to this height. Lowest corners height changes as this happens and so the ECU does it again until your on the bump stops, annoying but normalish behaviour for the P38 IF parked on un-even ground.

So, get reading the heights and see what's what.

-Wills

Hi Wills,

Did not use the calibration option, only de pressurize air springs.
Surface is fairly flat but not perfect.
Started car to do the checks and this time it came straight up, ie about 10 secs to ride height. I switched off to see what would happen and this time it stayed up. It's cold and dark now so I will continue tomorow on proper level surface and post results.
Thanks for your help. Don.

Don1 · Feb 5, 2009

Don1 said:
Hi Wills,

Did not use the calibration option, only de pressurize air springs.
Surface is fairly flat but not perfect.
Started car to do the checks and this time it came straight up, ie about 10 secs to ride height. I switched off to see what would happen and this time it stayed up. It's cold and dark now so I will continue tomorow on proper level surface and post results.
Thanks for your help. Don.

Been fine all week, suspect height sensor may have got confused after car been jacked up.

Many thanks for all suggestions.

Cheers.

Help! Suspension drops to bump stops when engine switched off.

Don1

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wills

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Don1

Active Member

wills

Well-Known Member

Don1

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Don1

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