P38A Pesky EAS!

Good evening, Haven't been on here for a while, project for rebuilding my P38 had to go on the back burner for a while. I've only just started back on it recently and decided that I'd try and get the suspension working if I could. I know there is soooo much for this topic but I've been reading so much the last few days that I've got a bit of information overload. Plus I can't seem to see exactly the problem I have.

It's a 01 2.5D and I've done the following with the suspension.

1. Rebuilt pump and valve block.
2. New pump.
3. Cut out the two connector blocks in the passenger footwell and soldered the wires together (there was some serious corrosion on the pins)
4. Swapped the EAS ECU
5. Swapped the delay relay.
6. Swapped the Switch on the dash.

I can raise and lower the bags on the EAS Unlock software. The bags will hold for days without dropping from the height I set them at. I have no lights on the ride control switch and can't change the heights with it, there is 12v power coming to the switch. The 35mph warning is on the dash.

It was parked up for a good year and a half beside my mothers house on the bump stops, but to give it it's due I threw a battery into her, pumped the primer a few times and she started straight up and drove to my house not a problem (bar the uncomfortable ride on the bump stops, it was only a quarter mile so not too bad)

It's been so long sitting and it got damp inside the cabin that I'll be going around to do all the earth points again just to rule them out. It's parked in a nice dry garage now.

I think I've covered most of the points.

Thanks.
D.

The 35mph warning indicates a hard fault. Have you tried reading the faults or alternatively have you clicked on the "Unlock" button.
No lights on the height switch suggests a bad connection somewhere, but first try reading the faults.

I did but I got different faults every time. Last nights rabbit hole research suggests faulty usb adaptor cable/drivers. Is there special drivers that come with the original cable/mine was an eBay special (CH341SER drivers)? If there is would someone be able to email me a copy of them or a link to them?

Thanks.
D.

Digweed said:

I did but I got different faults every time. Last nights rabbit hole research suggests faulty usb adaptor cable/drivers. Is there special drivers that come with the original cable/mine was an eBay special (CH341SER drivers)? If there is would someone be able to email me a copy of them or a link to them?

Thanks.
D.

Click to expand...

Is your cable USB without an adaptor? If so you will need to contact the cable maker for details of the driver. If you are using a USB to serial adaptor, it needs to be an FTDI device with a full RS232 implementation. The driver has to be loaded before the cable or USB adaptor is plugged in or Windows will load a generic driver that will not operate the EAS. If you have plugged in first, then the driver will have to be removed and the correct one installed.

It's not an ftdi one. Manufacturer is listed as wch. I'll get one of those ftdi ones. I'll report back when i have one.

Thanks.
D.

Digweed said:

It's not an ftdi one. Manufacturer is listed as wch. I'll get one of those ftdi ones. I'll report back when i have one.

Thanks.
D.

Click to expand...

You need to make sure it has a the full RS 232 implementation with the signal lines RTS, DTS and CTS. Many do not have those lines only the RX & TX lines.
I have not come across wch, the other common USB to serial adaptors are by Prolific but the ones I have will not work on Win 10.

I'm in the process of digging out an old pc with a serial port and rebuilding it. With any luck that'll do it.

I had three old dell machines sitting in the attic all with serial ports, couldn't get any of them to work so I ordered the FTDI adapter. I've that plugged in and now all I get is PP in the Rx column. I've tried changing the delay but nothing. It's amazing how difficult it is to find a laptop with a serial port now!!!

Digweed said:

I had three old dell machines sitting in the attic all with serial ports, couldn't get any of them to work so I ordered the FTDI adapter. I've that plugged in and now all I get is PP in the Rx column. I've tried changing the delay but nothing. It's amazing how difficult it is to find a laptop with a serial port now!!!

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Before plugging in the FTDI adaptor, you should have installed the correct driver otherwise, as has been said many times, Windows will install a generic driver that uses the X-on/X-off protocol rather than the RTS/CTS protocol. You also have to be sure the FTDI adaptor you bought is a full RS232 implementation that supports RTS/CTS.

All that was done. Been going through datasheets for the last while and as far as I can make out it does have RTS/CTS protocol. The only thing I could find is that there is a new driver out. the one on the CD was 2017. I've updated that. I'll let you know how it goes.

Right. I figured out what was wrong. I'd changed the relay a while back and forgotten I'd swapped it for the original one. Put in the new one and lovely communication!!! BTW you've no idea how dumb I feel after driving 2 hours to buy a laptop with a serial port. Anyways I still have no lights on the selector switch and the 35MPH message is still on the dash. There's no faults detected when I read them. The last thing I did last night was to depressurise the springs and tank so I can start fresh later on this evening. There wasn't a heck of a lot of air left in either. I'll report back later tonight.

Digweed said:

Right. I figured out what was wrong. I'd changed the relay a while back and forgotten I'd swapped it for the original one. Put in the new one and lovely communication!!! BTW you've no idea how dumb I feel after driving 2 hours to buy a laptop with a serial port. Anyways I still have no lights on the selector switch and the 35MPH message is still on the dash. There's no faults detected when I read them. The last thing I did last night was to depressurise the springs and tank so I can start fresh later on this evening. There wasn't a heck of a lot of air left in either. I'll report back later tonight.

Click to expand...

Sounds like the compressor is not making enough pressure.

Right I left it running for about 15 minutes and when I got back in the garage the rear of the car was sky high. It'll drop down using the software but won't go back up unless the pump is running. The front doesn't seem to want to move at all. I'll check the pump but I think it's a new never used pump that I got off a friend of mine who used to be a Jag/Land Rover mechanic. I have a few of them lying about. I'm still stumped about why the switch isn't working though. I might be able to lay my hands on another EAS control module but I'd rather not start changing too many things at once.

Digweed said:

Right I left it running for about 15 minutes and when I got back in the garage the rear of the car was sky high. It'll drop down using the software but won't go back up unless the pump is running. The front doesn't seem to want to move at all. I'll check the pump but I think it's a new never used pump that I got off a friend of mine who used to be a Jag/Land Rover mechanic. I have a few of them lying about. I'm still stumped about why the switch isn't working though. I might be able to lay my hands on another EAS control module but I'd rather not start changing too many things at once.

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The back should rise first. It sounds like there is a leak at the front. The EAS ECU rarely fails.

Thanks. Might just try disconnecting it and checking the pins for corrosion. It's one thing I haven't tried yet. I've chopped and soldered the two big blocks that are in the passenger footwell and some of those pins were dark green.

Digweed said:

Thanks. Might just try disconnecting it and checking the pins for corrosion. It's one thing I haven't tried yet. I've chopped and soldered the two big blocks that are in the passenger footwell and some of those pins were dark green.

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You may need to do the same blocks in the drivers side footwell too.

Thank you, I'll have a look there.

If you run the car with a door or tailgate open it should just pressurise the tank and not rise. If it still does, either someone has messed with it, or you have internal leaks in the valve block allowing pump air to feed the bags while running.

Update from todays escapade. Ran the compressor with the tailgate open for about twenty minutes. When I was on the 'Get sensor heights' screen I found that I could move the suspension down with the switch on the dash went up once or twice but stopped then, wouldn't do it on any other screen and there was no leds lit on the switch. I find that the only way to get the compressor to run is using the command on the software. Is it possible the control board at the pump is faulty?

Digweed said:

Update from todays escapade. Ran the compressor with the tailgate open for about twenty minutes. When I was on the 'Get sensor heights' screen I found that I could move the suspension down with the switch on the dash went up once or twice but stopped then, wouldn't do it on any other screen and there was no leds lit on the switch. I find that the only way to get the compressor to run is using the command on the software. Is it possible the control board at the pump is faulty?

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There is no control board at the pump. Have you checked that the pump is making good pressure? It should not take 20 minutes to fill the tank.