P38A A series of faults

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I doubt you will see much continuity through the driver pack, if I remember correctly the output drivers are MOSFETS which are driven via IC's and a small transistor so there is no direct path that will give much of a meaningful response on a DVM.
That last link you posted says "Complete valve block" no mention of compressor or driver pack. I got caught like that early on in my P38 ownership. It's cheap if it's complete.
 
Datatek said:
I doubt you will see much continuity through the driver pack, if I remember correctly the output drivers are MOSFETS which are driven via IC's and a small transistor so there is no direct path that will give much of a meaningful response on a DVM.
Click to expand...

Indeed they are, there's a row of them sitting at the bottom of your pic of the de-potted Driver Pack, and they were the suspects in my more electrically savy mates diagnosis of the potential problem.

Still digging through RAVE looking for the wire colours for the Driver Pack input, although I could probably relate them directly to the C152 Valve Block Connector from ECU key I suppose...
 
The inputs are 12v signals on pins 1-6 on the connector at front of EAS housing.

Power & ground are 10+11 and 12+13.

the others are for the pressure switch.
 
Yeah figured it out using the C152 connector diagram.

All the Male Pins on the connectors were absolutely fine and really clean. No sign of oxidation or failed crimps so far.

Going to look at the Female socket sides now
 
It's usually connectors C139 or C140 that cause issues, i.e. the pair that connect between driver pack & solenoids.

If you got the block & driver pack to Langley I could bench test the whole lot for you. I've built a manual control box for bench testing, plus manual control of the EAS when working on the car. Also got a set of gauges for testing valve block seals, especially where there's no external leaks, but issues with NRV-s or valve not seating properly..
 
The the pins on the Male one of the 'C139' pair all looked pristine when I popped each one out to check the wire crimps to the pins. I need to tackle the female part next

I'm reliably informed it could just be the car being a P38 and needing to be cycled a number of times for it to finally twig the order of things....but it did get cycled a fair bit yesterday.

If it carries on being daft tomorrow I maybe in touch about making a run over to you with it, as during the week I'm a little closer to you than I am right now
 
Although the pins & sockets may look good it’s better to use a spare pin to check the fit. I extract one of the pressure switch pins, and then use that to check the fit on each socket contact.
 
Couldn't find anything wrong with the Female Sockets going to the solenoids, have tightened all of them so it's now a really snug fit now the connectors are joined back up again
 
So, an odd day.

Having been through all the connectors, male and female, I could find nothing wrong and everything was nice and snug fitting.

I reassembled and refitted the unit and plumbed it back in.

I started the engine and left the driver's door open to let it fill the reservoir. With that done I opened the drivers window and shut the door. It then raised the car to the extreme 'grounded' (high centred?) ride height, so I got in and sent it to Standard height and it wnet to standard height. Hurrah! Drove it round the yard a tiny bit and all seemed well, parked it and it went down to access height with it in Park and Handbrake On. More Hurrah! I closed the drivers window. And it went up to the extreme 'grounded' ride height with the top indicator flashing and is now steadfastly refusing to go back down...

:mad:

ARGGGGGGHHHHHH!

I have collected a second complete Valve Block and Pump unit (the one from my ebay link) which I got for 80 quid. Am going to go through the connectors on that now...

:rolleyes:

The only thing I can think of is perhaps I have a fault in the 'grounded' vehicle sensing system which is overiding everything when it is triggered, I did read in the LR System Information Document that: 'The system will default to extended ride height if the system is unable to lower a sensor's bit count for any ten-second period' Could this be my smoking gun?
 
Slooby said:
So, an odd day.

Having been through all the connectors, male and female, I could find nothing wrong and everything was nice and snug fitting.

I reassembled and refitted the unit and plumbed it back in.

I started the engine and left the driver's door open to let it fill the reservoir. With that done I opened the drivers window and shut the door. It then raised the car to the extreme 'grounded' (high centred?) ride height, so I got in and sent it to Standard height and it wnet to standard height. Hurrah! Drove it round the yard a tiny bit and all seemed well, parked it and it went down to access height with it in Park and Handbrake On. More Hurrah! I closed the drivers window. And it went up to the extreme 'grounded' ride height with the top indicator flashing and is now steadfastly refusing to go back down...

:mad:

ARGGGGGGHHHHHH!

I have collected a second complete Valve Block and Pump unit (the one from my ebay link) which I got for 80 quid. Am going to go through the connectors on that now...

:rolleyes:

The only thing I can think of is perhaps I have a fault in the 'grounded' vehicle sensing system which is overiding everything when it is triggered, I did read in the LR System Information Document that: 'The system will default to extended ride height if the system is unable to lower a sensor's bit count for any ten-second period' Could this be my smoking gun?
Click to expand...
Check the earth points under the EAS box. Check the connectors at the foot of the A post both sides.
 
Earth point on behind the foot well trim on the OS A post is very clean, no sign of corrosion or oxidised copper on the wires connected to it:

HovPV3H.jpg


Couldn't find one on the NS:

3Uw2q4G.jpg
 
While looking at the earth on the OS I also found more work for myself...

The heater matrix has a weap and is splashing drops of pink coolant onto the transmission tunnel carpet :(

The usual reason for heater matrices to spring a leak is corrosion due to a poor earth...
 
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