EAS question

Paul Coddington · Jan 16, 2023

Evening All
I am aware that there is loads of threads regarding the air suspension on the P38, but rather than trawl though potentially years of questions and answers I'm throwing it out to you all.
Vehicle is a year 2000, Manual 2.5dt
On first start up yesterday, EAS fault appeared on the message screen. followed not long after by the "slow 35mph message", shortly afterwards I connected the EASunlock diagnostics up and a fault of RL signal incorrect and the vehicle has moved one also.
I had to leave it at that yesterday and returned to the problem today,
Firstly I got a whole raft of error codes some of which were contridicting each other "pressure signal constantly high, Pressure signal constantly low" among them. I read up of previous posts led me to think that this was a connection/communcation error and I shut down and restarted. This time there were no faults shown although the 35 mph messageis still on the dash and the Air suspension is not operating on the dash controls.
Connecting the vehicle to the diagnostics removes the dash message which re appears as soon as I shut the software down.
Has anyone come across a similar fault and if so what was the solution please. Any ideas of what is potentially wrong, would be welcome.
The vehicle did develop a slight list to the right at the end of last week, so assume that is part of the same problem.

oakey · Jan 16, 2023

You need to clear the fault using the software.
Does vehicle drop overnight?
If not then ,maybe sensor problem

Paul Coddington · Jan 16, 2023

oakey said:
You need to clear the fault using the software.
Does vehicle drop overnight?
If not then ,maybe sensor problem

Hi Thanks for the reply, The fault has already been cleared and hasn't re appeared, the vehicle doesn't drop overnight but does go down over a period of a couple or three days if not used.
I am suspisious of the left rear sensor that was the first fault on the software, but my last P38 was on coil springs and I'm not knowledgeable about the air system.

oakey · Jan 16, 2023

If you have a small leak then the car should self level until eventually on bump stops.
Does it end up on bump stops after 3 days or listing?

Paul Coddington · Jan 16, 2023

oakey said:
If you have a small leak then the car should self level until eventually on bump stops.
Does it end up on bump stops after 3 days or listing?

I couldn't honestly say if it is on the stops, probably not but I'll leave it a this week and see how far it drops

oakey · Jan 16, 2023

Good plan

Paul Coddington · Jan 16, 2023

oakey said:
Good plan

brianp38dse · Jan 16, 2023

If you remover the eas delay relay under the passenger seat it will not self level and will show if a bag is leaking that corner will drop
if there is a leak then the pump may well need a rebuild as it will have been working more to overcome the leak.

Paul Coddington · Jan 17, 2023

brianp38dse said:
If you remover the eas delay relay under the passenger seat it will not self level and will show if a bag is leaking that corner will drop
if there is a leak then the pump may well need a rebuild as it will have been working more to overcome the leak.

Thanks for your help, I'll get have a look at that today.

Datatek · Jan 17, 2023

Paul Coddington said:
Evening All
I am aware that there is loads of threads regarding the air suspension on the P38, but rather than trawl though potentially years of questions and answers I'm throwing it out to you all.
Vehicle is a year 2000, Manual 2.5dt
On first start up yesterday, EAS fault appeared on the message screen. followed not long after by the "slow 35mph message", shortly afterwards I connected the EASunlock diagnostics up and a fault of RL signal incorrect and the vehicle has moved one also.
I had to leave it at that yesterday and returned to the problem today,
Firstly I got a whole raft of error codes some of which were contridicting each other "pressure signal constantly high, Pressure signal constantly low" among them. I read up of previous posts led me to think that this was a connection/communcation error and I shut down and restarted. This time there were no faults shown although the 35 mph messageis still on the dash and the Air suspension is not operating on the dash controls.
Connecting the vehicle to the diagnostics removes the dash message which re appears as soon as I shut the software down.
Has anyone come across a similar fault and if so what was the solution please. Any ideas of what is potentially wrong, would be welcome.
The vehicle did develop a slight list to the right at the end of last week, so assume that is part of the same problem.

Multiple faults as said means bad comms. You need to get the green "Good Idle" to indicate communication has been established. If the "Slow 35mph" message remains after disconnecting, it means the fault is still there, you probably just have not seen it due to a comms problem. If the EAS fault appeared at start up, quit possibly the RL (Rear Left) sensor is the problem. The car dropping or a leak will not flag a fault on start up. If the car was leaning, that could be the sensor or a leak, either way it needs working diagnostics to progress.
Vehicle has moved can be ignored, it just means the height has changed since the ignition was last turned off, as the car self levels every 6 hours when parked, that message is almost always there.

Paul Coddington · Jan 17, 2023

Datatek said:
Multiple faults as said means bad comms. You need to get the green "Good Idle" to indicate communication has been established. If the "Slow 35mph" message remains after disconnecting, it means the fault is still there, you probably just have not seen it due to a comms problem. If the EAS fault appeared at start up, quit possibly the RL (Rear Left) sensor is the problem. The car dropping or a leak will not flag a fault on start up. If the car was leaning, that could be the sensor or a leak, either way it needs working diagnostics to progress.
Vehicle has moved can be ignored, it just means the height has changed since the ignition was last turned off, as the car self levels every 6 hours when parked, that message is almost always there.

Thanks for the reply, just comeback in the vehicle had definitely dropped slightly on the left but did rise back up when I started the engine. No fault codes before I started her up, but did get some odd height readings on the rear left wheel. I think I'm going to change the rear air bags, both the front where done at the end of last year. The sensors can get changed at the same time... hopefully that'll get it.

Datatek · Jan 17, 2023

Paul Coddington said:
Thanks for the reply, just comeback in the vehicle had definitely dropped slightly on the left but did rise back up when I started the engine. No fault codes before I started her up, but did get some odd height readings on the rear left wheel. I think I'm going to change the rear air bags, both the front where done at the end of last year. The sensors can get changed at the same time... hopefully that'll get it.

If the airbags are old, almost certainly they will be leaking, the design life was 8 years 80K miles. Odd readings from the sensor may just be corrosion in the connector but no harm in replacing them if one is giving odd readings. Worth the expense if you are keeping the car long term. You will need to calibrate all heights after fitting new sensors.

Paul Coddington · Jan 17, 2023

Datatek said:
If the airbags are old, almost certainly they will be leaking, the design life was 8 years 80K miles. Odd readings from the sensor may just be corrosion in the connector but no harm in replacing them if one is giving odd readings. Worth the expense if you are keeping the car long term. You will need to calibrate all heights after fitting new sensors.

I've printed the guide off that comes with the software ready for that eventually!

Paul Coddington · Jan 17, 2023

I don't know if this is a symptom of anything but the vehicle won't stay on its highest suspension settings, even when it's connected to the laptop. It goes back down to standard height almost immediately.

Datatek · Jan 17, 2023

Paul Coddington said:
I don't know if this is a symptom of anything but the vehicle won't stay on its highest suspension settings, even when it's connected to the laptop. It goes back down to standard height almost immediately.

That is possibly a symptom of corrosion in the white connectors at the foot of the A post behind the kick panel passenger side, a very common problem.
The solution is to cut and solder the wires one by one insulating with heat shrink. The connectors are only there for assembly of the car and are not necessary. Could also be related to your suspect height sensor.

Salisbury Nick · Jan 17, 2023

Notwithstanding everything that @Datatek said - who should be listened to most carefully - I had the same issues exactly as you first described them - and again, not withstanding the fact that multiple things can be wrong at the same time and compound a problem, after a lot of mucking about with my EAS over a very long time - replacing a faulty sensor eventually cleared all of my issues. At least for a while....

Paul Coddington · Jan 17, 2023

Back in from the cold, I love laying on the floor in this!! I've had a look at the rear air bags and they look pretty new ( I have a photo if anyone is willing to give a second opinion). Previous owner told me he had changed the front but it seems the back have been done as well.
Also the ride height display is behaving oddly, the ride height will now drop to access, rise back up to standard but will not actually rise to high, the light flashes and eventually the high and standard lights are both illuminated, but the vehicle hardly moves if at all.
I'm going to take a look at the connections in the left hand footwell and change the sensors before touching anything else.

Datatek · Jan 17, 2023

Paul Coddington said:
Back in from the cold, I love laying on the floor in this!! I've had a look at the rear air bags and they look pretty new ( I have a photo if anyone is willing to give a second opinion). Previous owner told me he had changed the front but it seems the back have been done as well.
Also the ride height display is behaving oddly, the ride height will now drop to access, rise back up to standard but will not actually rise to high, the light flashes and eventually the high and standard lights are both illuminated, but the vehicle hardly moves if at all.
I'm going to take a look at the connections in the left hand footwell and change the sensors before touching anything else.

Send me a photo of the airbags, I'll PM you with an email address.
It might be worth checking the compressor output. Also, remove the little silencer towards the rear of the valve block and check for white powder.

Paul Coddington · Jan 17, 2023

Salisbury Nick said:
Notwithstanding everything that @Datatek said - who should be listened to most carefully - I had the same issues exactly as you first described them - and again, not withstanding the fact that multiple things can be wrong at the same time and compound a problem, after a lot of mucking about with my EAS over a very long time - replacing a faulty sensor eventually cleared all of my issues. At least for a while....I Thanks for the advice, I have had

Paul Coddington · Jan 17, 2023

Paul Coddington said:
[/QUOTE
Oops hit the wrong button on the last post

EAS question

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