p38 eas

hi new to this great forum,i have a 1996 p38 ,i have a question regarding the eas system,should the valve block be making noises when engine is off (not be going for a day)when came home from work heard it working,sounded like it was trying to adjust the heights,but no one was near it,dont know if this is supposed to happen or not any info would be much appreiciated thanks

dove said:

hi new to this great forum,i have a 1996 p38 ,i have a question regarding the eas system,should the valve block be making noises when engine is off (not be going for a day)when came home from work heard it working,sounded like it was trying to adjust the heights,but no one was near it,dont know if this is supposed to happen or not any info would be much appreiciated thanks

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Yes it will equalise pressure side to side when you get out. Should last a few seconds then go to sleep via timer relay.

Sorry misread that. No not after a day it sould not. Timer relay should go to sleep and not come back in until engine is started again. Common cause of flat battery and dropping to bump stops is faulty timer relay not going to sleep. Under front passenger seat.

the motor was left stationary for at least 16 hours and nobody went near it or in it in that time.and thats when i heard what seems to be the valve block ticking away.i thought everything would be shut down when ignition is switched off.there are no faults with it ,all airbags have been replaced recently.another thing i noticed the other day,i have recently fitted a towbar.i went to pick up a car on a trailer when it was all loaded up the suspension went to offroad height and would not adjust down all the lights were on on the level height indicator on the dash does this seem correct?

what relay do you ask for then

dove said:

the motor was left stationary for at least 16 hours and nobody went near it or in it in that time.and thats when i heard what seems to be the valve block ticking away.i thought everything would be shut down when ignition is switched off.there are no faults with it ,all airbags have been replaced recently.another thing i noticed the other day,i have recently fitted a towbar.i went to pick up a car on a trailer when it was all loaded up the suspension went to offroad height and would not adjust down all the lights were on on the level height indicator on the dash does this seem correct?

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No when you load back end sensors change value air is then pumped in until they regain nominal set height. Think you need to check that all the ride heights are set correctly. Think you maybe getting a bad sensor reading from somewhere. Reason for delay relay is when you get in car drivers side sensors will change reading air will be pumped in to adjust level returning sensor to nominal. So whilst you are in there, there is more air pressure in O/S bags than in N/S. When you get out that pressure will cause car to rise at O/S changing sensor readings the car will then equalise pressure O/S to N/S so car sits level again. Then relay goes to sleep after about 20 seconds. It should not be clicking 16 hours later. I know there are problems with RF recievers picking up stray signals and waking BECM. But i don't think it wakes up the EAS. Someone may have different ideas on this.

mine does the same click,click,click now and then had flat battery

biggledom said:

what relay do you ask for then

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EAS delay timer relay.

is this a problem caused by parking on uneven ground, my driveway has a steep access and if rr aint parked square on driveway it happens

would wireless p/c cause probs if rr parked close to house with wireless p/c connection

biggledom said:

is this a problem caused by parking on uneven ground, my driveway has a steep access and if rr aint parked square on driveway it happens

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Yes if delay relay is not asleep. As the sensors will have differing readings and the EAS will try and level itself. It does not put air in, only releases it. Hence the morning bump stop problem.

biggledom said:

would wireless p/c cause probs if rr parked close to house with wireless p/c connection

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If your RF reciever is duff yes very possibly. But i think Rf reciever waking BECM will only effect EAS if EAS delay relay is not going to sleep. It should only be woken up when engine starts.

is there anyway to check this relay?done a quick search on the net and are about £50.if the sensors were giving a false reading would this not log a eas fault it only done it when the trailer was hooked up. it is always ok,it moves through its positions almost instantly. thanks for all the replys

dove said:

is there anyway to check this relay?done a quick search on the net and are about £50.if the sensors were giving a false reading would this not log a eas fault it only done it when the trailer was hooked up. it is always ok,it moves through its positions almost instantly. thanks for all the replys

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Well something triggered the christmas tree effect. Read the faults again and see what you have.

is there anyway to check this relay? think they are about£50if the sensors were giving false readings would this not put up an eas fault?it only happened when trailer was hooked up,it works fine all other times,up and down almost instantly .thanks for replys

I had the same and it was two things both mentioned by Wammers first was the relay was fooked second was a rear nearside sensor working intermittently every now and then it would give the christmas tree but never showed a fault took ages to find - check all connections etc first - also and this will sound a bit nuts but pull fuse 7 in the fuse box under the bonnet and see if there is a burning smell as when these fuse boxes go down al sorts of odd problems arrive I had this as well. good luck

wammers said:

Yes it will equalise pressure side to side when you get out. Should last a few seconds then go to sleep via timer relay.

Sorry misread that. No not after a day it sould not. Timer relay should go to sleep and not come back in until engine is started again. Common cause of flat battery and dropping to bump stops is faulty timer relay not going to sleep. Under front passenger seat.

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According to my reading of RAVE, it wakes up every 6 hours and re-levels, this is to compensate for possible small leaks that would otherwise leave the car at a drunken angle. It will often if parked on uneven ground level all the way down to access height when the process stops.

Datatek said:

According to my reading of RAVE, it wakes up every 6 hours and re-levels, this is to compensate for possible small leaks that would otherwise leave the car at a drunken angle. It will often if parked on uneven ground level all the way down to access height when the process stops.

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OK can live with that, but think there is also something about not losing more than 15mm in height in 24 hrs through leakage. So if this process causes bump stops overnight there would appear to be a much larger leak on one of the corners than that. Relay not sleeping at all is given as flat battery cause in technical bulletins.

wammers said:

OK can live with that, but think there is also something about not losing more than 15mm in height in 24 hrs through leakage. So if this process causes bump stops overnight there would appear to be a much larger leak on one of the corners than that. Relay not sleeping at all is given as flat battery cause in technical bulletins.

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15mm or 5mm in 24 hours, not sure which without looking, but thats parked on flat level ground.
Park mine on the flat, it drops less than 5mm overnight, outside my front door at a crazy angle and it will sometimes drop 20mm in the same period.
If the car drops dramatically overnight, personally my first thought would be a leak rather than the relay.

Datatek said:

15mm or 5mm in 24 hours, not sure which without looking, but thats parked on flat level ground.
Park mine on the flat, it drops less than 5mm overnight, outside my front door at a crazy angle and it will sometimes drop 20mm in the same period.
If the car drops dramatically overnight, personally my first thought would be a leak rather than the relay.

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Yes more likely to be a leak i agree. Think it is 15mm from memory. But if the relay is faulty and there is a small leak it will drop to bump stops even on level ground, depending on the severity of the leak. The system has no way of knowing how much air pressure is in each individual bag, it takes it's commands from the sensor positions and tries to equalise them. A glitching sensor, maybe through moisture ingress (one that now and then gives a simular reading in different positions) can also cause leveling problems.

Yes a worn sensor can produce some strange problems.