I went to Germany this week and left the car at High, and disconnected the battery. I came back, reconnected, as I've done many times. Started her up no problem, and went to run an errand...but...no response when i went to lower the ride height. Being stuck at high is not the worst thing in the world, but i need to use it on the road tomorrow, so looking for a fix. The system has been fine for 5 years, but recently in the last few months it wd sometimes sag at the Rear RH corner when i left her parked. I'm convinced it was the system doing the deflating and not a leak... i could be shopping for 5 mins and would come back and it had gone down... other times it would just sit at standard, and it would sit at high all day long. But now as i say it wont adjust from High.... Well, I say wont, but i can plug nano in and make the car go up and down, all the sensor bit counts adjust dynamically. Fuses are ok, and switches test ok on the nano - except the raise/ lower one - which would be a red flag, but i took the switch of my other P38 and nano reads the same - no response to the ride height switch.... I'm suspecting the EAS ECU, which I suppose is easy enough for me to try... but, does anyone have any alternative theories?
I’m guessing, but what about set it to standard height with nano then remove the timer relay and plug it back in to reset it. Or disconnect and reconnect the EAS ECU?
If it is on High it should drop down to standard at 35 mph. Does it or does it just stay there all the time? Try using the Nano to open the exhaust valve and a couple of corner valves and see if it drops then. That will rule out the valve block and driver pack.
I changed out the ECU for another (no 2) and that ECU set the car to standard height with all the height settings for the other car - i guess that infor is held in flash memory. Then I changed back to the original ECU (no1) and it defaulted back to High, with the original height settings. Changing the relays didn't help either.
Car goes up and down on nano - and i can do separate valves too - the only thing is it is slow to rise back up...
I took the car for a spin, with the original ECU. Since i'm in London, it's basically 5 miles to get somewhere where i can go over 35, and for 60 mph I ended up doing a 40 mile round trip. The car dropped to standard height first , and then motorway height, and then back up on my return journey - all as expected. Still no response to the switch though. I wonder if there's a state where the ECU is programmed to ignore the ride height switch - like insufficient pressure from the pump? The pump runs... but it feels like it should be making the adjustment faster.
There is a fault reported, btw, but it just says "code not recognised"...helpful
Sounds like your pump is getting a bit weak but that wouldn't affect the height or the switch not working. The switch isn't just a switch, there's some electronics inside it too, so I would suspect that has died. At least you've got another you can try swapping to prove or otherwise.
I already switched the switch- that made no difference. My other P38 is in bits at the mo (fixing the heater box)... I will try and rebuild that tomorrow to compare. The other thing i was thinking was the wiring from the switch to the EAS ECU... or at least the connectors...it seems to be routed through the LH footwell.... I have soldered up the connector with the wiring for the outstation, but not the other one... i'll take a look at that tomorrow too.
Tnx for the assistance
If not wiring consider the EAS Valve Block driver ...... and/or the multi-way connector to it (notably for corrosion/damp) ?
C104... Lots of the green stuff...cut out and soldered up, all fine now
Great to hear