E61 level control system failure
Discussion
A few days ago, I parked my 525d LCI at home, and there was a loud buzzing noise from the offside rear. It carried on after I had locked the car.
I went indoors and googled the problem to see what it might be, and the rear suspension pump seemed to be the favourite suggestion. By the time I went back outside, the noise had stopped, so I figured it was just one of those things.
I used the car for the next 2 days, and all seemed well.
Today, shortly after leaving home, I got "level control system failure" on the screen, and a yellow car with arrows icon on the dash.
When I got home, I checked the fuses in the load compartment, and the 40A one for the compressor had blown.
The rear was low on both sides - no gap between tyre tread and top of wheel arch.
I replaced the 40A fuse, and the compressor started running straight away, without the key in the ignition.
The pump continues to run, but the car doesn't lift. After a couple of minutes, I pulled the fuse, and it was getting pretty warm to the touch.
I left the fuse to cool down, and plugged it back in. Again, the compressor ran OK, no lifting, but the noise level reduced a little. Fuse started to get warm, so I pulled it again.
More googling, and it seems that the compressor should switch off after 30 seconds or so, so that it doesn't overheat. Mine doesn't. I guess when I first heard the noise a few days ago, the compressor only stopped because the fuse blew?
I've owned the car for nearly 3 years, and this is the first sign of any trouble with the level control. Compressor running for a long time, then 2 days later, the warning message.
I can't for the life of me remember how high the rear of the car normally sits. At the front, there is a visible gap between the top of the tyre and the wheel arch. At the rear, the top of the tyre is about 20mm inside the wheel arch. Is this the normal stance, or is the rear suspension really sitting on the bump stops? When I was driving it, it all felt fine. It's an M Sport, on 18's.
Any ideas?
I went indoors and googled the problem to see what it might be, and the rear suspension pump seemed to be the favourite suggestion. By the time I went back outside, the noise had stopped, so I figured it was just one of those things.
I used the car for the next 2 days, and all seemed well.
Today, shortly after leaving home, I got "level control system failure" on the screen, and a yellow car with arrows icon on the dash.
When I got home, I checked the fuses in the load compartment, and the 40A one for the compressor had blown.
The rear was low on both sides - no gap between tyre tread and top of wheel arch.
I replaced the 40A fuse, and the compressor started running straight away, without the key in the ignition.
The pump continues to run, but the car doesn't lift. After a couple of minutes, I pulled the fuse, and it was getting pretty warm to the touch.
I left the fuse to cool down, and plugged it back in. Again, the compressor ran OK, no lifting, but the noise level reduced a little. Fuse started to get warm, so I pulled it again.
More googling, and it seems that the compressor should switch off after 30 seconds or so, so that it doesn't overheat. Mine doesn't. I guess when I first heard the noise a few days ago, the compressor only stopped because the fuse blew?
I've owned the car for nearly 3 years, and this is the first sign of any trouble with the level control. Compressor running for a long time, then 2 days later, the warning message.
I can't for the life of me remember how high the rear of the car normally sits. At the front, there is a visible gap between the top of the tyre and the wheel arch. At the rear, the top of the tyre is about 20mm inside the wheel arch. Is this the normal stance, or is the rear suspension really sitting on the bump stops? When I was driving it, it all felt fine. It's an M Sport, on 18's.
Any ideas?
The gap on 18" MV2 Sport alloys from the bottom of the wheel rim to the wheel arch should be either 605mm or 607mm depending on where you look.
Or a more rough test is you should get about 2 1/2 fingers in the gap...
Is it dropping on one or both sides? If both and you say it worked the other day I'd it's likely that the bags are fine.. Although leaving them flat ruins them.
It sounds like the air isn't getting from the compressor to the bags, the compressor will keep running as there's no resistance. Could also be the relay??
The air comes out the compressor into a solenoid valve, this then splits it straight to the left or right.. These valves do go bad but I'd look at the air hoses first and see if they're still attached! It's a lot more basic system than it may appear.
Or a more rough test is you should get about 2 1/2 fingers in the gap...
Is it dropping on one or both sides? If both and you say it worked the other day I'd it's likely that the bags are fine.. Although leaving them flat ruins them.
It sounds like the air isn't getting from the compressor to the bags, the compressor will keep running as there's no resistance. Could also be the relay??
The air comes out the compressor into a solenoid valve, this then splits it straight to the left or right.. These valves do go bad but I'd look at the air hoses first and see if they're still attached! It's a lot more basic system than it may appear.
Edited by philmots on Thursday 16th April 21:13
Thanks for the info.
Bottom of rim to wheel arch is 575mm on both sides, so it's sitting 30mm low. I guess if the bags were empty, it would be lower than that?
Are the solenoid valves part of the compressor assembly?
Is the relay in the spare wheel well, or in the fuse box?
From what I've read, the ECU should shut down the compressor after less than a minute to prevent it overheating, even if the ride height is still low. Mine carries on running until I pull the fuse. This suggests that it might be a stuck relay, or a faulty ECU.
Presumably each side has it's own solenoid valve, so it's unlikely they have both failed?
I wonder if the original fault was a duff relay, compressor stayed on and blew the fuse? Doesn't explain why the car is now sitting 30mm low - unless the ECU knows something is wrong, and isn't opening the valves?
Bottom of rim to wheel arch is 575mm on both sides, so it's sitting 30mm low. I guess if the bags were empty, it would be lower than that?
Are the solenoid valves part of the compressor assembly?
Is the relay in the spare wheel well, or in the fuse box?
From what I've read, the ECU should shut down the compressor after less than a minute to prevent it overheating, even if the ride height is still low. Mine carries on running until I pull the fuse. This suggests that it might be a stuck relay, or a faulty ECU.
Presumably each side has it's own solenoid valve, so it's unlikely they have both failed?
I wonder if the original fault was a duff relay, compressor stayed on and blew the fuse? Doesn't explain why the car is now sitting 30mm low - unless the ECU knows something is wrong, and isn't opening the valves?
There's just one solenoid valve which has one input from the compressor and 2 outputs, left and right.. It's located on the compressor but isn't available separately from BMW, I replaced mine as the air distribution side to side was out intermittently. I bought this, it's identical to what came off...
http://www.air-suspension-shop.com/BMW-E61-double-...
I'm not 100% where the relay is located, but it's available from them although it's not listed on their site.
It sounds like yours is more of an electrical issue so when i'd had a look for anything obviously wrong, I'd probably look at changing that out first for the reasons you suggest.
The only odd thing is that when the compressor is running, nothing's happening.. Where's that air going?
It could just be a perished tube.
Whilst you're in there I'd replace the compressor feed pipe if you've the original rubber one too, that's the cause of most compressor failures.
The old tube breaks and sucks unfiltered grit etc in to the compressor.
http://www.air-suspension-shop.com/BMW-E61-double-...
I'm not 100% where the relay is located, but it's available from them although it's not listed on their site.
It sounds like yours is more of an electrical issue so when i'd had a look for anything obviously wrong, I'd probably look at changing that out first for the reasons you suggest.
The only odd thing is that when the compressor is running, nothing's happening.. Where's that air going?
It could just be a perished tube.
Whilst you're in there I'd replace the compressor feed pipe if you've the original rubber one too, that's the cause of most compressor failures.
The old tube breaks and sucks unfiltered grit etc in to the compressor.
Must be my lucky day!
I figured I had nothing to lose, so I emptied out the boot to gain access to the electrics tray in the spare wheel well (bit of a struggle, as I have a spare wheel kit, and the liner is a pig to remove) and pulled the relay.
I opened it up, and the contacts were welded closed. Frred them off, cleaned up with wet or dry, blew out the debris, and finished off with a bit of isopropyl alcohol.
I put the relay back in, fitted a new fuse, and - silence!
Started the car, and the compressor fired up, car lifted an inch. All apears to be OK, so I'll check it with a drive to the dealer to pick up a new relay.
I guess what happened is the relay failed, compressor ran until the fuse blew, and after a few days the suspension sagged an inch. The ECU tried to compensate, but the compressor wouldn't run, so I got the error message.
When I was testing it with a new fuse, the car wasn't low enough for the ECU to try and compensate ( I didn't start the engine at that point) so it didn't open the air valve, but the compressor ran because the relay was closed.
The pump is a lot quieter now too, so maybe the high resistance across the burnt relay was causing it to struggle. Low voltage, higher than normal current, rough running?
I figured I had nothing to lose, so I emptied out the boot to gain access to the electrics tray in the spare wheel well (bit of a struggle, as I have a spare wheel kit, and the liner is a pig to remove) and pulled the relay.
I opened it up, and the contacts were welded closed. Frred them off, cleaned up with wet or dry, blew out the debris, and finished off with a bit of isopropyl alcohol.
I put the relay back in, fitted a new fuse, and - silence!
Started the car, and the compressor fired up, car lifted an inch. All apears to be OK, so I'll check it with a drive to the dealer to pick up a new relay.
I guess what happened is the relay failed, compressor ran until the fuse blew, and after a few days the suspension sagged an inch. The ECU tried to compensate, but the compressor wouldn't run, so I got the error message.
When I was testing it with a new fuse, the car wasn't low enough for the ECU to try and compensate ( I didn't start the engine at that point) so it didn't open the air valve, but the compressor ran because the relay was closed.
The pump is a lot quieter now too, so maybe the high resistance across the burnt relay was causing it to struggle. Low voltage, higher than normal current, rough running?
Just got back from the dealer with a new relay - £14 inc VAT. 50 mile round trip, and no problems.
I'll buy some axle stands next time I'm in town, whip off the arch liner and check the intake tubing for splits. Having had a lucky escape this time, I'll eliminate the common problem.
Not the end of my car problems though. As I left the house earlier, I noticed something shiny lying on the driveway. Passenger wing mirror glass had fallen off the Z4. Just the glass, separated from the backing plate and heater. The adhesive pad had separated. £97 from BMW!
Checking eBay now. The Z4 is being traded next week.
I'll buy some axle stands next time I'm in town, whip off the arch liner and check the intake tubing for splits. Having had a lucky escape this time, I'll eliminate the common problem.
Not the end of my car problems though. As I left the house earlier, I noticed something shiny lying on the driveway. Passenger wing mirror glass had fallen off the Z4. Just the glass, separated from the backing plate and heater. The adhesive pad had separated. £97 from BMW!
Checking eBay now. The Z4 is being traded next week.
Timmydun did you get to the bottom of your issue ?
I have similar issue car will every now and then drop on the rear suspension, compressor will fire up and run but not lift the car, then all of a sudden will lift, so I assumed it was the solonoid not working so bought a second hand one but same problem, car will be fine for weeks then it will drop and not go up even with the compressor running, now wondering if it’s a wiring problem that controls the solonoid ? Or was my supposedly tested solonoid faulty too ? Any info appreciated, mine is an E61
I have similar issue car will every now and then drop on the rear suspension, compressor will fire up and run but not lift the car, then all of a sudden will lift, so I assumed it was the solonoid not working so bought a second hand one but same problem, car will be fine for weeks then it will drop and not go up even with the compressor running, now wondering if it’s a wiring problem that controls the solonoid ? Or was my supposedly tested solonoid faulty too ? Any info appreciated, mine is an E61
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