Thread: SLS Cycling - with resultant flattened battery

Has the suspension been raised? If so, the rear sls height sensors may be confused.
Also pin holes in the air suspension bags is another common problem that causes the sls pump to cycle more.
Could be some other problem, a short somewhere, causing the battery to loose charge? Keep us updated.
Wasa 57

does your air suspension stay up without the compressor repeatedly cylcing on/off?

pull the fuse to find out if needs be, this will tell you if your bags are leaking (and 99% of SLS leaks are the bags!)

cheers

+1

Pin holes in the air suspension bags is another common problem that causes the sls pump to cycle more. This will not flatten your battery while the car is turned off, the suspension will just sag until you turn the car on again. The ABS system draws power even when car is off, that will flatten your battery if the car is parked up long enough.

Thanks for the replies. I'm stumped a bit on this. There was no pump cycle going on (ie inflation of the air bags), just the clicking. In normal operation with the ignition off, the pump shouldn't be cycling, but the SLS does deflate the suspension if required to hold to a height for a period of time after the vehicle has been run. The suspension was at normal height. I've got new bags on the workbench but the last soap test (some 3 months ago) didn't t indicate any leaks, even on full height.

My initial thoughts was that it was like it was trying to deflate (ie clicking being the solenoids operating) with no air being released. It hasn't done it since, with either the old or the new battery.

The car hadn't been run for a few days prior to this happening, so it most probably wasn't a relay stuck, as the battery would have been flat (and I would have noticed it, as I'm in the garage a bit), rather than just being a bit marginal.....

I'll keep the post up to date, if and when it happens again.....

soapy water test is hit and miss while the bag is still on the vehicle. It took me a couple of goes over several days before I was able to confirm that the bag was leaking. When the bag is out of the car with the fold taken out stretching the bag to full length makes it much easier to detect the leak.

I've had a flat battery a couple of times and believe it has to do with the SLS, athough I have modified mine by replacing compressor and using an air tank, I think there might be a couple of slow leaks. If the car has been left for a long period the battery dies (which was recently replaced with Optima yellow top) and the suspension sags, I believe my solenoid is constantly trying to allow air into the bags which puts a constant drain on the battery, either that or maybe the height sensors are draining the battery, whatever the cause it has only started happening since I changed my air setup and installed a dual battery controller.
Cheers Matt

Hi imatt,
From experience, for your leaking SLS air I would be looking at a slow leak from any of the joins you put in when you modified the air set up.

The leak is very unlikely to be from the OE solenoids. If the sags only started after you fiddled with things

Took me lots of searching to find a very slow almost imperceptible leak from a t piece I put in may sls piping. I had to wait and watch each soaped up join for minutes to see the bubble finally appear at the culprit.

Good luck

Yeah I reckon there is a slow leak in a join somewhere, I have already had to re do my shraeder valves a couple of times because they kept leaking (its amazing how much teflon tape you need on some threads, I thought a couple of wraps would do it). I'm probably just a bit lazy at chasing the leaks, as long as I use the vehicle regularly its fine. I just wonder if when the suspension sags and the vehicle is off then one of the sensors/solenoids operates to try and raise the vehicle but while its off nothing happens, hence a constant drain on the battery, even if a small drain.
Cheers Matt